Strobel v. Johnson & Johnson ( 2021 )


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  • Filed 9/21/21
    CERTIFIED FOR PUBLICATION
    IN THE COURT OF APPEAL OF THE STATE OF CALIFORNIA
    FIRST APPELLATE DISTRICT
    DIVISION FOUR
    JO ANN STROBEL,
    Plaintiff and Appellant,             A159609
    v.                         (Solano County Super. Ct.
    JOHNSON & JOHNSON et al.,                   No. FCS052548)
    Defendants and Respondents.
    Douglas Strobel was diagnosed with malignant mesothelioma in
    February 2019 and passed away at age 68 in April 2020, during the pendency
    of this appeal. Before his death, Strobel sued Johnson & Johnson (J&J) for
    damages under product liability, negligence and fraud theories, alleging that
    continuous exposure to asbestos in J&J’s Baby Powder (JBP), a product he
    used regularly for some sixty years, was a substantial contributing cause of
    his mesothelioma. Strobel’s wife, Jo Ann, a coplaintiff who substituted in as
    the sole appellant after his death, seeks recovery for loss of consortium.
    The trial court granted summary judgment for J&J. Pointing to the
    declaration of J&J’s expert, Dr. Matthew Sanchez, who swore that JBP was
    at all relevant times asbestos-free, the court ruled that the Strobels failed to
    present evidence creating a triable issue of legal causation. The Strobels filed
    declarations from five experts, Drs. Sean Fitzgerald, Steven Compton,
    Murray Finkelstein, and Richard Cohen, and Mr. Charles Ay, all
    contradicting J&J’s experts on this point.
    1
    The court sustained J&J’s hearsay objections to much of the Strobels’
    proffered expert testimony under People v. Sanchez (2016) 
    63 Cal.4th 665
    (Sanchez) and for lack of foundation. It then concluded that, after the
    exclusion of this testimony, the Strobels could not bear their burden of proof
    on legal causation because what was left—the opinions from Drs. Fitzgerald
    and Compton—only confirmed the presence of asbestos in the talcum ore J&J
    used to manufacture JBP, not in JBP offered for sale as a finished product
    during the years Doug Strobel used it. Without relying on case-specific
    hearsay about which these experts had no personal knowledge, the court
    ruled, they could only speculate about the presence of asbestos in JBP during
    the exposure period.
    This appeal followed the entry of judgment for J&J. We now reverse.
    I. BACKGROUND
    A. Doug Strobel’s History of Using JBP
    Starting shortly after his birth in 1951, Doug Strobel’s mother
    regularly used JBP when diapering him as an infant. As a young boy, Doug
    developed what would become a lifelong habit of applying JBP on himself,
    coating his feet in it and dumping it in his shoes after little league baseball
    practice to reduce odor. When he applied JBP to his feet in this way, a cloud
    of it would arise around him. Doug continued this habit as he grew older,
    applying JBP to his feet two to three times a week for nearly six decades,
    until 2014. Every two months or so, his wife, Jo Ann, routinely bought
    containers of JBP for Doug’s use, as his mother had done when he was a boy.
    One of the Strobels’ experts testified that, over the course of his lifetime,
    Doug Strobel used at least 338 containers of JBP. While none of this is
    disputed, whether asbestos was present in JBP during the six-decade
    exposure period is a matter of sharp dispute.
    2
    B. Whether JBP Was Contaminated with Asbestos: The State of the
    Evidence on Summary Judgment
    The Strobels were unable to produce any containers of the JBP that
    Doug Strobel actually used or to arrange for testing of the contents of those
    containers, since all of them were consumed years ago. But the Strobels did
    make a showing that, over the course of Doug Strobel’s lifetime, he was not
    exposed to asbestos from any source other than JBP.1 Generally speaking,
    the proof bearing on whether JBP contained asbestos during the period 1951
    through 2014 fell into two categories. First, there were opinions from
    physicians specializing in asbestos-related diseases who considered Doug
    Strobel’s lifetime habit of using JBP and addressed whether it was a likely
    cause of his mesothelioma (Drs. Cohen and Finkelstein for the Strobels and
    Dr. Moolgavkar for J&J2). Second, there was evidence from geologists and
    1 The absence of some source of asbestos exposure other than JBP is the
    thrust of the expert declaration from Charles Ay, a certified consultant with
    expertise in workplace asbestos exposure. Ay identifies 12 types of commonly
    used industrial products that are known to contain asbestos (joint compound,
    fireproofing, gaskets and packing, brakes and clutches, dryer felts, asbestos-
    cement pipe, gloves and cloth, electrical insulation, floor tile, thermal systems
    insulation, gun plastic cement, and stucco). Having worked for many years
    as a pipefitter in the marine insulation and construction industries, Ay
    gained familiarity with the nature and properties of asbestos by actually
    working with these asbestos-containing industrial products.
    2 Dr. Cohen, a clinician with a private practice, and Dr. Finkelstein, a
    retired government consultant on asbestos regulation, are both professors of
    occupational health and environmental medicine. Dr. Moolgavkar is a cancer
    epidemiologist and research scientist. Although Drs. Cohen, Finkelstein, and
    Moolgavkar have widely varying professional profiles, each is a physician
    with special expertise in one or both of the fields of epidemiology (the
    incidence, patterns, and causes of disease in human populations) and
    industrial toxicology (the investigation of the health effects of dust,
    chemicals, metals, toxic materials, and physical agents on workers who may
    be exposed in the workplace).
    3
    asbestos detection experts who conducted geological and mineralogical
    analyses, using microscopic examinations and other techniques to test for the
    presence of asbestos in JBP milled as a finished product and in the source
    talc ore used to manufacture it (for the Strobels, Dr. Compton [source ore
    only] and Dr. Fitzgerald [source ore and milled JBP], and for J&J,
    Dr. Sanchez [source ore and milled JBP]3).
    Among all the physicians who submitted declarations for and against
    summary judgment, it was undisputed that mesothelioma is a signal tumor
    almost always associated with exposure to asbestos. Dr. Cohen opined
    without contradiction that inhaled asbestos fibers can become lodged in the
    lungs or the pleural cavity around the lungs, and that when the body is
    unable to expel these fibers through its natural immune response, they may
    cause genetic damage at the cellular level, ultimately causing mesothelioma.
    Dr. Cohen further opined, here too without contradiction, that there may be a
    long latency period between exposure to asbestos and the development of
    asbestos-related diseases (10–50 years is “normal”); that “mesothelioma is a
    very low dose disease, with no known minimum threshold of exposure to
    3  Dr. Compton, a physicist, works in the areas of “particle analysis,
    asbestos analysis, industrial hygiene, and the physics of small particles.” He
    specializes in “the identification, measurement and analysis of materials,
    determining the constituent ingredients in materials, and characterizing
    those materials and ingredients, including asbestos and talc.” Dr. Fitzgerald
    is “a licensed Professional Geologist, mineralogist and asbestos expert, with
    over 30 years of experience analyzing asbestos minerals and researching and
    developing the science of asbestos.” He is familiar with regulatory standards
    governing asbestos and has “substantial training and experience in the
    analysis of asbestos and asbestos-containing materials, including
    transmission electron microscopy, scanning electron microscopy, x-ray
    diffraction and polarized light microscopy.” Dr. Sanchez, a geologist,
    specializes in “characterizing asbestos in raw materials and in building
    products and the development of asbestos analytical methods.”
    4
    asbestos below which there is no risk”; and that the chance of disease
    developing from exposure to asbestos is “proportional to” cumulative dosage
    over time.
    From there, however, the physicians for each side sharply disagreed.
    For the Strobels, Dr. Cohen opined that “to a reasonable degree of medical
    certainty . . . [the JBP] Douglas Strobel used and was exposed to for decades,
    starting 68 years ago” contained asbestos “above normal background levels”;
    “that his use of and exposure to asbestos from [JBP] was a significant and
    impactful contributing factor in the development of his mesothelioma”; and
    that “Douglas Strobel’s exposure to asbestos was the cause of his
    mesothelioma.” Dr. Finkelstein concurred. J&J, for its part, contended that
    Doug Strobel’s mother sometimes used a brand of cosmetic talcum powder
    manufactured by Colgate-Palmolive rather than JBP, but did not dispute the
    absence of any unusual source of asbestos exposure in Doug Strobel’s life
    other than talcum powder, nor did it claim he had any habits such as
    smoking that put his lungs at particular risk. Rather, J&J disputed legal
    causation based on Dr. Moolgavkar’s view that mesothelioma, like all
    cancers, can develop spontaneously, that mesothelioma may be triggered by
    any number of carcinogens commonly found in today’s environment, and that
    the risk of contracting mesothelioma is strongly correlated with a person’s
    age.
    The principal difference between the physician experts was this. The
    Strobels’ physicians gave weight to the opinions of Drs. Fitzgerald and
    Compton, who each attested that consumer powders made from talc produced
    from the mining regions where J&J obtained talc contained asbestos, while
    Dr. Moolgavkar did not, giving weight instead to the likelihood of other
    potential asbestos exposure sources and general risks that anyone may face
    5
    in developing mesothelioma. The Strobels’ physicians cited the extensive
    literature relating to the geology and mineralogy of asbestos, discussed
    testing methodologies for detecting asbestos, and used statistical analysis—
    extrapolating from the frequency and incidence of positive asbestos findings
    in the tests undertaken by others—to opine on the percentage likelihood that
    asbestos would be present in any given container of JBP during the time
    Doug Strobel used it. But because none of the physicians actually conducted
    any tests for the presence of asbestos in JBP or in the talc ore used to
    manufacture JBP, the testimony of the geologists and asbestos testing
    experts had dispositive significance in the trial court’s analysis.
    As further explained below, the trial court ruled that Dr. Compton’s
    and Dr. Fitzgerald’s declarations, to the extent they infer the presence of
    asbestos in milled, finished talcum powder from nothing more than positive
    tests for asbestos in raw talc ore used to manufacture it, are legally
    insufficient to create a triable issue of fact under applicable principles of
    causation. And to the extent Dr. Fitzgerald’s declaration went beyond that,
    opining that asbestos was present in JBP itself during the exposure period,
    the court ruled that his opinion constituted inadmissible case-specific hearsay
    under Sanchez, supra, 63 Cal.4th at pages 684–686, which in effect left the
    opinions of Dr. Sanchez and Dr. Moolgavkar unrebutted.
    C. The Geology and Mineralogy of Talcum and Asbestos
    To frame the issues that divided the opposing experts in this case in a
    more specific way, we pause for a brief tour through the science that
    undergirds their opinions. Much of that science is undisputed. Talcum, or
    “talc” as the parties refer to it in shorthand, is a hydrated magnesium silicate
    mineral. One of the softest minerals on earth, at the far end of a spectrum
    opposite to, say, diamond, talc is used in a wide variety of commercial
    applications ranging from pharmaceuticals and cosmetics to ceramics, paints,
    6
    paper, and asphalt roofing. Talcum powder, a talc-based cosmetic product, is
    manufactured by a milling process in which large pieces of talc ore are
    crushed and pulverized into fine-grained powder.
    There are essentially two types of talc ores, industrial grade and
    cosmetic/pharmaceutical grade, depending on the particular deposit from
    which the ore comes. Talc deposits vary with regard to chemistry,
    morphology and habit. Chemistry in this context refers to the elemental
    composition of a mineral.4 Morphology refers to the size and shape of
    particles in a mineral. And habit refers to the form, crystal structure and
    texture in which a mineral is found in nature. Certain talc deposits, valued
    for their purity, softness and fine particle size, tend to be the ones used for
    cosmetic products.
    “Asbestos” is a collective term describing a regulated group of six
    naturally occurring, highly fibrous silicate minerals that grow in a unique
    crystalline form as bundles. Geologists describe this growth habit as
    “asbestiform.” In the process of being crushed in the talcum powder milling
    process, asbestiform bundles are easily separated into long, thin, flexible
    fibers. When crystallized in an asbestiform habit, the six minerals that are
    regulated as asbestos fall into two mineral families: serpentine and
    amphibole. Both mineral families grow in asbestiform and nonasbestiform
    4 To geologists, a “mineral” is a regular and specific arrangement of a
    given chemistry (chemical elements that are present in a certain ratio or
    amount). Only ten elements in the periodic table of elements make up 98.8
    percent of the earth’s crust, namely, in order of abundance: oxygen, silicon,
    aluminum, iron, calcium, sodium, potassium, magnesium, titanium, and
    hydrogen. “Silicates,” which are made up of four oxygen atoms bonded to a
    single silicon atom and arranged in the pyramidal shape of a tetrahedron, are
    a family of minerals.
    7
    habits. Serpentine and amphibole minerals with a nonasbestiform
    morphology are not regulated as asbestos.
    Talc and asbestos minerals are distinct, but they are closely related in
    their geological formation and thus often found together in nature. Because
    magnesium, silica, and water are the essential ingredients in talc and
    asbestos, both minerals form under the same conditions. They both grow
    within formations of either continental rock or ocean crustal rock.
    Continental rock, which includes layered sedimentary rock of many varieties,
    is dominated by the elements silicon and aluminum, while ocean crustal rock,
    known as basalt—and further classified by geologists as either mafic or
    ultramafic in origin—is both silica poor and magnesium and iron rich.
    As a result, asbestos is often found intergrown as an “accessory
    mineral” within a talc deposit. Serpentine tends to appear in talc deposits in
    mafic and ultramafic host rocks while amphiboles and serpentine tend to
    appear in talc deposits in sedimentary host rock. The growth of talc and
    asbestos within either of these two types of host rock occurs by complex
    metamorphic processes. According to Dr. Fitzgerald, the asbestos minerals
    most likely to be found as accessory minerals within talc are chrysotile, the
    fibrous form of serpentine, and the asbestiform varieties of three amphibole
    minerals: actinolite, tremolite, and anthophyllite.
    Summing up the geology and mineralogy of asbestos in general terms,
    Dr. Fitzgerald states that the three most common asbestos accessory
    minerals found in talc (anthophyllite, tremolite and chrysotile) “form under
    similar conditions in regional or contact metamorphism of ultramafic rocks
    especially in the presence of carbonates and water, as all of these minerals
    are hydroxylated magnesium silicates.” And according to Drs. Cohen and
    Finkelstein, who add an epidemiology perspective, of those three, all have
    8
    documented histories as carcinogens when humans are exposed to them in
    dust form.
    D. Testing for Asbestos
    Asbestos fibers are very small, so small, in fact, that millions of fibers
    could fill the air in a room without anyone being able to perceive them with
    the naked eye. Testing to detect them, as a result, requires specialized
    technology that can identify particles at the level of microns, a unit of
    measurement that is approximately 70 times smaller than the breadth of a
    human hair.5 These tiny fibers are distinguished by having a large aspect
    (length to diameter) ratio with highly parallel sides and are crystallized in an
    asbestiform morphology that causes them to separate into very thin fibers or
    fibrils. There are several analytical methods for detecting and identifying
    asbestos fibers. Each method has advantages and disadvantages. Bulk
    sampling identifies how much asbestos is in a product or material. Air
    sampling identifies how many asbestos fibers are released into the air.
    For identifying asbestos in bulk materials, X-Ray Diffraction (XRD)
    determines the crystalline structure of minerals by measuring the response
    angles and intensities of an X-ray beam reflected through the lattice
    structure of a mineral. This method yields a mass percentage of different
    minerals present, but it has a detection limit around 1 percent for the
    regulated asbestos minerals and is incapable of detecting individual asbestos
    5 Microns are denoted by the symbol µm. Nowhere in any of the
    thousands of pages of often highly technical expert declarations in this case
    does any expert explain the relative size of a micron as a unit of
    measurement. Since the comparison of a micron to the breadth of a human
    hair is helpful for explanatory purposes, under Evidence Code section 451,
    subdivision (f ), we will take judicial notice of it. (Ley, Diameter of a Human
    Hair (1999) in The Physics Factbook (Elert edit.)  [as of Sept. 21, 2021].)
    9
    fibers. Polarized Light Microscopy (PLM), which can determine the different
    asbestos types by optical properties and asbestiform morphology, also allows
    positive asbestos identification at the level of individual fibers, but is limited
    in its resolution and does not allow for positive identification of smaller fibers
    (e.g., shorter than 5 µm long, or narrower than 0.25 µm, the types of fibers
    that, according to Dr. Fitzgerald, are typically found as contaminants in talc).
    Some experts in asbestos materials testing—Dr. Fitzgerald, for
    example—believe that Transmission Electron Microscopy (TEM) is the most
    reliable instrument for detection and identification of all asbestos types,
    especially in air sampling because of its higher resolution and thus higher
    sensitivity to the presence of individual asbestos fibers. The high-energy
    electron beam used in TEM allows resolution of even the thinnest 0.02-µm
    asbestos fiber, and Selected Area Electron Diffraction (SAED) can determine
    if the crystalline structure is one of the asbestos mineral types. As a further
    refinement, an Energy Dispersive X-ray detector (EDX) interfaced with a
    TEM yields elemental composition, confirming particle chemistry. According
    to Dr. Fitzgerald, TEM can therefore determine the morphology, structure,
    and chemistry definitional to asbestos minerals, at a resolution capable of
    defining asbestos fibers at the finest level.
    Other experts in asbestos materials testing—Dr. Sanchez, for
    example—believe that electron microscopy alone is a suboptimal method to
    test for the presence of asbestos. According to Dr. Sanchez, the combination
    of XRD and PLM has been approved by the United States Food and Drug
    Administration (FDA) as a method of testing talcum powder for decades.
    Dr. Sanchez holds the view that, because PLM analysis examines a greater
    number of particles than TEM analysis, and because TEM images alone only
    depict morphology—yielding accurate information only if used with SAED
    10
    according to a rigorous protocol called the Yamate Level III Method6—
    examination of populations of particles is best performed by PLM.
    E. The Opinions of Dr. Fitzgerald and Dr. Compton
    In opposition to J&J’s summary judgment motion, Dr. Fitzgerald
    opined for the Strobels that “geologists have known for well over a century of
    the intimate relationship between talc and asbestos.” He further opined that,
    to determine the presence of asbestos as accessory minerals in talc mining
    ore, “we must closely and carefully examine” the talc formation from which
    the talc is mined, both from the “macroscopic geology of formation to the
    microscopic examination of materials and minerals as they change through
    time.”
    During the exposure period in question here—1951 through 2014—J&J
    obtained talc that was later formulated into JBP from three mining sources:
    (1) from 1951–1967, the Val Chisone and Val Germanasca region of
    Piedmont, Italy, (2) from 1968–2003, the Windsor region in the state of
    Vermont, and (3) from 2003–2014, from Guangxi Province, near Guilin City,
    in China. Dr. Fitzgerald opined without contradiction that metamorphic
    processes in all three of these areas are conducive to the formation of
    asbestiform anthophyllite, tremolite, or chrysotile as accessory materials
    within talc.
    According to Dr. Sanchez, “[t]he Yamate Level III Method is a TEM
    6
    protocol that describes a quantitative type of SAED analysis. The Yamate
    Method has three increasingly rigorous levels of analysis, and under the
    Yamate Method Level III, in specified circumstances an analyst must obtain
    diffraction patterns from two different zone axes to positively identify a
    mineral as an amphibole. . . . This is particularly true in talc, where talc and
    anthophyllite, for example, can yield similar diffraction patterns depending
    on the orientation of the particle to the electron beam.”
    11
    Dr. Fitzgerald tested samples from the Italian source ore and reported
    that, “I found both asbestiform anthophyllite and asbestiform tremolite, and
    occasionally chrysotile asbestos, not only present in the talc, but easily made
    airborne when product use was simulated by my own hand.” Dr. Compton, a
    physicist with expertise in asbestos testing, tested talc ore samples from
    Italian and Vermont mining regions used by J&J and reported results
    consistent with those of Dr. Fitzgerald.7
    According to Dr. Compton, “the asbestos content of . . . samples [for the
    Italian talc ore] found to contain amphibole and chrysotile fibers range[s]
    from approximately 1.7 to 660 million fibers per gram,” and for the Vermont
    ore found to contain amphibole fibers, the range was 1.16 to 15.3 million
    fibers per gram. “Fiber release studies of consumer talc products within this
    range,” Dr. Compton opined, show “elevated concentrations of airborne
    asbestos fibers during use of those products. It is expected that
    aerosolization of these samples or any powder consumer product containing
    these samples as a constituent ingredient would likewise result in elevated
    concentrations of airborne asbestos fibers.”
    Addressing J&J’s Chinese talc, Dr. Fitzgerald relied primarily on the
    geology of the region. According to Dr. Fitzgerald, talc deposits in the
    Guangxi region are “[c]omprised chiefly of siliceous carbonate rock derived
    from marine sediments subsequently metamorphosed to low-grade
    greenschist assemblages.” He explained, further, “it is well recognized
    7 The declaration of Dr. Fitzgerald references the ore samples he tested
    as “AGI 1615,” a designation that he uses to describe ore as coming from a
    specific mining location in the Val Chisone/Val Germanasca region known as
    the Fontane Mine. Dr. Compton also tested ore from the Fontane Mine.
    According to Dr. Compton, the Fontane Mine has been in operation since the
    seventeenth century.
    12
    that the metamorphism of siliceous dolomites invariably forms tremolite,
    often fibrous.” In addition to commenting on the regional geology of J&J’s
    Chinese talc, Dr. Fitzgerald also observed that, in 2019, the FDA, through a
    contract laboratory, conducted tests of “Chinese talc-based Johnson &
    Johnson baby powder . . . , with repeated findings of asbestos in the
    products.”
    F. Summary Judgment for J&J
    Upon examination of the evidence presented in support of, and in
    opposition to, J&J’s motion for summary judgment, the trial court
    determined that J&J carried its initial burden of production, thus shifting
    the burden to the Strobels on the issue of legal causation. After scrutinizing
    the Strobels’ evidence in opposition to the motion, the trial court assumed
    arguendo that the Strobels had presented through Drs. Fitzgerald and
    Compton “competent direct evidence that samples of source ore associated
    with deposits at some source mines have been found to contain asbestos.”
    But that was not enough to meet the test of legal causation. Looking
    downstream from the mining sources of talcum ore, the court focused on
    whether “the talc ore from a deposit that actually contained asbestos was
    milled into talcum powder and then actually used in JBP sold during
    Plaintiff’s exposure period.” The key witness on this issue was
    Dr. Fitzgerald, who tested five JBP samples obtained from J&J’s historical
    archives, reporting positive tests for asbestos in four of them, but none of
    these asbestos-positive samples dated from within the exposure period.
    The testing results in the record confirming the presence of asbestos in
    JBP marketed by J&J during the six-decade-plus exposure period at issue—
    presented with laboratory bench data specifying the number of asbestos
    structures counted—came from asbestos testing expert Dr. William Longo.
    Dr. Longo has presented these test results through testimony and expert
    13
    reports in other asbestos litigation against J&J, but he was not designated as
    an expert in this case. Drs. Fitzgerald, Cohen and Finkelstein all cited and
    relied on Dr. Longo’s reported test results.8 Drs. Finkelstein and Cohen had
    no foundation to rely upon Dr. Longo’s test results, the trial court ruled, since
    his work was outside their area of expertise. And “to the extent” any of the
    Strobels’ experts, including Dr. Fitzgerald, relied on Dr. Longo, the court
    ruled that their opinions were inadmissible case-specific hearsay under
    Sanchez.
    The court overruled most of J&J’s objections to Dr. Compton’s proffered
    opinion, but since he tested only mined ore, it concluded that that still left a
    gap in the Strobels’ evidence they could not overcome. Having ruled that, “to
    the extent” Drs. Fitzgerald, Cohen, and Finkelstein rely on inadmissible
    hearsay and that Mr. Ay was not competent to address the presence of
    asbestos in JBP, the trial court turned to the Strobels’ remaining evidence of
    exposure to milled and formulated retail containers of JBP. The court noted
    the Strobels’ evidence included a number of studies that have been published
    over the years reporting positive tests for asbestos in JBP samples, but
    concluded the Strobels failed to “establish a hearsay exception that
    permit[ted] [them] to use these documents to prove the truth of the matter,
    rather than the limited non-hearsay purpose of notice to [J&J].” Ultimately,
    the court found, the Strobels “fail[ed] to establish triable issues of fact to link
    the harvesting of a known deposit of asbestos-contaminated talc ore from a
    particular mine through the milling process and into a canister of JBP sold in
    stores during the exposure period.”
    8 Mr. Ay stated it was his understanding that “talc, an ingredient in
    Johnson’s baby powder used by Mr. Strobel . . . , contained asbestos,” without
    specifying the basis of that statement.
    14
    II. DISCUSSION
    A. Legal Standards
    We begin with familiar legal standards.
    A trial court must grant a motion for summary judgment “if all the
    papers submitted show that there is no triable issue as to any material fact
    and that the moving party is entitled to a judgment as a matter of law.”
    (Code Civ. Proc., § 437c, subd. (c).) When, as here, defendants move for
    summary judgment, they can “meet their burden by demonstrating that ‘a
    cause of action has no merit,’ which they can do by showing that ‘[o]ne or
    more elements of the cause of action cannot be separately established . . . .’ ”
    (Id., subd. (o)(1); Nazir v. United Airlines, Inc. (2009) 
    178 Cal.App.4th 243
    ,
    253.) “The defendant has shown that the plaintiff cannot establish at least
    one element of the cause of action by showing that the plaintiff does not
    possess, and cannot reasonably obtain, needed evidence.” (Aguilar v. Atlantic
    Richfield Co. (2001) 
    25 Cal.4th 826
    , 854.)
    If that initial burden is met, the burden shifts to the plaintiff “to show
    that a triable issue of one or more material facts exists as to the cause of
    action or a defense thereto.” (Code Civ. Proc., § 437c, subd. (p)(2).) “There is
    a triable issue of material fact if, and only if, the evidence would allow a
    reasonable trier of fact to find the underlying fact in favor of the party
    opposing the motion in accordance with the applicable standard of proof ”
    (Aguilar v. Atlantic Richfield Co., 
    supra, 25
     Cal.4th at p. 850), which here is
    the preponderance of the evidence (Rutherford v. Owens-Illinois, Inc. (1997)
    
    16 Cal.4th 953
    , 965 (Rutherford )).
    “ ‘On appeal “[w]e review a grant of summary judgment de novo; we
    must decide independently whether the facts not subject to triable dispute
    warrant judgment for the moving party as a matter of law. [Citations.]”
    [Citation.] Put another way, we exercise our independent judgment, and
    15
    decide whether undisputed facts have been established that negate plaintiff’s
    claims.’ ” (Turley v. Familian Corp. (2017) 
    18 Cal.App.5th 969
    , 977.) We
    “ ‘accept as true the facts . . . in the evidence of the party opposing summary
    judgment and the reasonable inferences that can be drawn from them.’ ”
    (Nazir v. United Airlines, Inc., supra, 178 Cal.App.4th at p. 254.) And in
    undertaking our analysis, “ ‘we must “ ‘view the evidence in the light most
    favorable to [the plaintiffs] . . .’ and ‘liberally construe [the plaintiffs’]
    evidentiary submissions and strictly scrutinize [the] defendant[’s] own
    evidence, in order to resolve any evidentiary doubts or ambiguities in [the
    plaintiffs’] favor.’ ” ’ ” (Turley, at p. 978.)
    We must, however, disregard any evidence to which legally correct
    objections have been made and sustained. (Guz v. Bechtel National, Inc.
    (2000) 
    24 Cal.4th 317
    , 334; Code Civ. Proc., § 437c, subd. (c).) Since the trial
    court’s evidentiary rulings excluding some of the Strobels’ proffered evidence
    are central to its analysis, our standard of review of those rulings is crucial.
    As we discuss in part II.B.2.a., post, there is some dispute in the case law
    (and between the parties) as to whether the de novo standard or the abuse of
    discretion standard should apply. “[T]he weight of authority holds that an
    appellate court reviews a court’s final rulings on evidentiary objections by
    applying an abuse of discretion standard.” (Carnes v. Superior Court (2005)
    
    126 Cal.App.4th 688
    , 694; see Serri v. Santa Clara University (2014)
    
    226 Cal.App.4th 830
    , 852.) But for reasons specific to this case cited in part
    II.B.2.a., post, we elect to employ a de novo standard of review.
    Turning from procedure to substance, the applicable substantive law
    focus here is on legal causation. As is frequently the case in asbestos
    litigation, that, in turn, requires us to consider the issue of exposure to
    asbestos. To prevail on “a cause of action for asbestos-related latent injuries,
    16
    the plaintiff must first establish some threshold exposure to the defendant’s
    defective asbestos-containing products.” (Rutherford, supra, 16 Cal.4th at
    p. 982.) Here, the determinative issue is whether the Strobels presented
    sufficient admissible evidence to create a triable issue of whether a
    reasonable jury could conclude it was more likely than not that the JBP Doug
    Strobel used contained asbestos. (LAOSD Asbestos Cases (2020)
    
    44 Cal.App.5th 475
    , 489.)
    B. Analysis
    We conclude that the Strobels presented sufficient admissible evidence
    on legal causation to create a triable issue. On summary judgment, the
    parties offered the court two starkly different expert perspectives: There
    was, on the one hand, the view presented by Drs. Compton and Fitzgerald
    that J&J obtained talc ore from sources contaminated with asbestos during
    the exposure period, a premise from which these experts draw the inference
    that asbestos was present in JBP when Doug Strobel used it. On the other
    hand, there was the view presented by Dr. Sanchez that J&J sorted and
    screened its ore in the mining process to ensure only the most pristine talc
    was used for cosmetic products, and that suppliers were subject to strict
    testing requirements—established under an FDA-approved testing protocol—
    to confirm that source ore used to make JBP was asbestos-free.
    Which of these competing views to accept must be decided at trial.
    Both camps of expert opinion extensively analyze historical records going
    back many decades, including government reports, published articles, and
    internal J&J memoranda, and arrive at opposite conclusions. One
    fundamental difference between the Fitzgerald and Compton perspective, on
    the one hand, and the Sanchez perspective, on the other, is in the respective
    methodologies the experts’ laboratories chose to use in testing samples of talc
    ore. Dr. Compton’s lab relied on a combination of XRD and TEM utilizing
    17
    microscopy equipment capable of both EDX and SAED, a testing approach
    Dr. Compton describes as generally accepted. Dr. Fitzgerald’s laboratory
    used a combination of XRD and TEM with SAED; according to him, the
    approach used by his lab is in accord with Environmental Protection Agency
    (EPA) guidelines and published authority in the field of microscopy. The
    TEM-based microscopy testing protocols used by Drs. Fitzgerald and
    Compton are sensitive enough to produce images at the level of individual
    asbestos fibers.
    Dr. Sanchez, by contrast, believes there is no generally acceptable
    methodology for TEM analysis. He prefers a combination of XRD and PLM,
    an approach approved by the FDA that his lab, RJ Lee Group, used.
    According to Dr. Sanchez, only by using this method can it be determined
    whether the sample ore being examined has a sufficient population of fiber
    bundles to indicate the presence of asbestiform fibers. In effect, he believes,
    the ultrasensitivity of TEM analysis is also its weakness. Without looking for
    populations of fibers of a specified size9 that have asbestiform habit,
    9  Dr. Sanchez uses a definition of asbestos that requires fibers to have
    very specific dimensions. In his view, a population of fibers having
    asbestiform morphology generally exhibits several characteristics, including
    mean aspect ratios that are in the range of 20:1 to 100:1 for fibers greater
    than 5 µm long; that are less than 0.5 µm wide; and that have at least two or
    more of the following additional features: (1) parallel fibers occurring in
    bundles, (2) fiber bundles displaying splayed ends, (3) matted masses of
    individual fibers, and (4) fibers showing curvature. Dr. Fitzgerald believes
    that Dr. Sanchez’s use of fiber populations and specified dimensions is an
    artificial way of excluding fibers less than 5 µm long that should be counted
    as asbestos structures. We note this point of definitional disagreement
    appears to be consistent with what has been reported about areas where
    consensus is lacking among causation experts in asbestos litigation. (See
    3 Faigman et al., Modern Scientific Evidence (2020–2021 ed.) Areas of
    scientific disagreement—Mesothelioma, § 26:28 [[“t]here is . . . disagreement
    18
    Dr. Sanchez believes, the “cleavage” in an individual fiber can easily be
    mistaken for an asbestiform fiber, generating a false positive test.10
    Whatever the merits of this line of critique, it goes to the weight and not the
    admissibility of the opinions offered by Drs. Fitzgerald and Compton
    confirming the presence of asbestos in Italian and Vermont source ore.
    1. The Colgate-Palmolive Cases: Berg and Lyons
    The trial court acknowledged that the Strobels presented competent,
    admissible evidence that there was asbestos in the Italian, Vermont and
    Chinese source ore used by J&J but concluded that was not enough to create
    a triable issue of fact. Relying primarily on Berg v. Colgate-Palmolive Co.
    (2019) 
    42 Cal.App.5th 630
     (Berg), the court reasoned that without evidence
    that there was asbestos in any retail JBP product, as milled and formulated
    [among experts] regarding the role of short (<5 µm) asbestos fibers in the
    causation of mesothelioma”].)
    10 Dr. Fitzgerald strongly disagrees with Dr. Sanchez’s “cleavage
    fragment” theory. “I have reviewed numerous reports from Dr. Sanchez’s
    laboratory,” Dr. Fitzgerald states, “and, more often than not, structures are
    deemed ‘cleavage fragments’ . . . . In the calculations of concentrations on
    such reports, cleavage fragments are tabulated as non-asbestos, and
    therefore not counted.” According to Dr. Fitzgerald, “[t]his practice is
    completely contradictory from the intent and letter of regulation specifying
    counting protocols for airborne asbestos.” Thus, while Dr. Sanchez suggests
    that Dr. Fitzgerald’s approach generates false positives, Dr. Fitzgerald
    suggests that Dr. Sanchez’s approach generates false negatives.
    Here too we have a difference of views between the opposing experts
    that is consistent with reported lack of consensus among causation experts in
    asbestos litigation generally. (See 3 Faigman et al., Modern Scientific
    Evidence, supra, Areas of scientific disagreement—Talc, mesothelioma and
    ovarian cancer, § 26:32, fns. omitted [“Experts disagree as to whether
    cosmetic talcum powder is contaminated with asbestiform minerals. Some
    have analyzed these samples and reported finding asbestos fibers, whereas
    others have not. The issue is clouded by the distinction between amphibole
    asbestos and amphibole cleavage fragments.”].)
    19
    into JBP in the years 1951 to 2014, no reasonable jury could conclude that
    Doug Strobel’s use of JBP during those years exposed him to asbestos. We
    disagree. This case is more like Lyons v. Colgate-Palmolive Co. (2017)
    
    16 Cal.App.5th 463
     (Lyons), which reversed a summary judgment grant for
    the defense in a case involving alleged exposure to asbestos in cosmetic
    talcum powder.
    In Berg, the plaintiff sued Colgate-Palmolive in 2017 claiming that his
    exposure many years before to a talc shave product once sold by Colgate-
    Palmolive’s corporate predecessor, the Mennen company, was a substantial
    factor in causing him to develop mesothelioma. (Berg, supra, 42 Cal.App.5th
    at p. 632.) The proof showed that, as a teenager, plaintiff Berg had been
    exposed to Mennen’s talc shave product for a three- or four-year period
    between 1959 and 1961 or 1962, and during that period, he had used four to
    six containers of it. (Ibid.) The proof also showed that, during his life,
    plaintiff Berg “was exposed to other products that contained asbestos as part
    of their design, such as cigarettes with asbestos-containing filters.” (Id. at
    p. 636.)
    There, as in this case, the defendant built its case for lack of causation
    upon an opinion from Dr. Sanchez, who defined asbestos as a “ ‘group of six
    naturally occurring, highly fibrous silicate minerals’ ” that, “ ‘when
    crystallized in a rare asbestiform habit’—‘likely account[ing] for less than 1%
    of the known world occurrences of each mineral’—‘are regulated as
    asbestos.’ ” (Berg, supra, 42 Cal.App.5th at p. 632.) “Relying on studies by
    other researchers and his own testing, [Dr. Sanchez] opined that Mennen
    Shave Talc was ‘free of asbestos’ and, even if some of the raw talc sourced to
    make the product was contaminated with asbestos, there was no legitimate
    scientific basis on which to conclude that any particular container of shave
    20
    talc was contaminated.” (Ibid.) And there, as here, the plaintiff relied on an
    opinion from Dr. Fitzgerald, who testified that the raw talc from the mines
    where Mennen sourced talc ore contained asbestos. (Id. at pp. 632–633.)
    Dr. Fitzgerald also tested Mennen’s shaving talc product in 2016 and 2018—
    nearly 60 years after plaintiff Berg’s last exposure to the product—in
    containers that “looked like” the ones the plaintiff used decades before. (Id.
    at pp. 633, 636.) The tested samples of Mennen shave talc revealed
    “ ‘countable structures of amphibole’ minerals, the majority of which ‘were
    clearly asbestiform in crystalline habit.’ ” (Id. at p. 633.)
    On that record, the Court of Appeal affirmed a summary judgment
    grant for Colgate-Palmolive, pointing out that plaintiff Berg had established
    no more than a possibility he had been exposed to asbestos in the accused
    Mennen product. “[E]ven assuming that some talc from the North Carolina
    and Italy mines contained some level of asbestos,” the trial court said, “the
    Fitzgerald declaration fails to support a conclusion that all or most of the
    Mennen Shave Talc containers sold from 1959 to 1962 contained asbestos.”
    (Berg, supra, 42 Cal.App.5th at p. 636.) Because “[t]he testing of the talc on
    which Fitzgerald relies, both his own and others’, occurred decades after the
    period of Berg’s use,” the court concluded, “Berg’s testimony that the
    containers Fitzgerald tested looked like the ones he used . . . falls far short of
    establishing that any containers of Mennen Shave Talc sold between 1959
    and 1961 or 1962 contained asbestos, much less that it is more likely than not
    that the containers Berg used contained asbestos.” (Ibid.)
    In Lyons, on the other hand, the appellate court reversed a summary
    judgment grant on a record where the “[p]laintiff alleged and at her
    deposition testified that she used” defendant Colgate-Palmolive’s “Cashmere
    Bouquet talcum powder from the early 1950’s to the early 1970’s.” (Lyons,
    21
    supra, 16 Cal.App.5th at p. 465.) After decades of applying Colgate-
    Palmolive’s talcum powder regularly to herself upon bathing, plaintiff Lyons
    was diagnosed with mesothelioma in 2015, the same diagnosis Doug Strobel
    received in this case. (Ibid.) Although Lyons did not keep any of the
    containers of talcum powder that she had used and she had no evidence
    showing positive tests for asbestos in Cashmere Bouquet sold at retail, here
    too like Doug Strobel, she presented a declaration from Dr. Fitzgerald
    reporting positive test results for asbestos in raw talc taken from three mines
    used by Colgate-Palmolive as sources of ore for the manufacture of Cashmere
    Bouquet, including the Val Chisone mine in Italy. (Id. at pp. 465–466.)
    Dr. Fitzgerald proffered testimony that his lab conducted bulk testing of
    Cashmere Bouquet product and concluded that “[t]he results of such testing
    are consistent with the makeup of the product, the ore, and the geology of the
    talc sources used by its manufacturer, Colgate.” (Id. at p. 467.)
    Colgate-Palmolive contended Dr. Fitzgerald’s declaration supported
    nothing more than a possibility of some asbestos in some Cashmere Bouquet
    sold at retail at some point in time, which left to conjecture whether the
    talcum powder the plaintiff used exposed her to asbestos. (Lyons, supra,
    16 Cal.App.5th at pp. 467–468.) In support of its position, Colgate-Palmolive
    argued that Dr. Fitzgerald’s testing of retail product had not been done on
    any tins of talcum powder that the plaintiff actually used and that his
    generally stated opinion as to the presence of asbestos in all Cashmere
    Bouquet lacked foundation. (Ibid.) The appellate court saw no basis for the
    evidentiary attack. It pointed to Dr. Fitzgerald’s opinion that “the evidence
    that talc from all three mines used in the manufacture of Cashmere Bouquet
    contained asbestos, repeatedly found in multiple tests and studies conducted
    before, during and after the 1950 to 1970 time period, coupled with plaintiff’s
    22
    use of the product over those 20 years, particularly in the absence of evidence
    of any other source of the asbestos causing plaintiff’s mesothelioma, creates
    more than an unsupported possibility.” (Id. at p. 469.) “Rather,” the court
    held, “there is a sufficient basis for the ‘inference[] reasonably deducible from
    the evidence’ that all or most of the Cashmere Bouquet that plaintiff used
    almost daily for 20 years contained harmful asbestos.” (Ibid.)
    As in Lyons, the summary judgment record here shows long term use of
    a talcum powder product alleged to contain asbestos by a mesothelioma
    sufferer who was not exposed to any other known source of asbestos above
    background asbestos levels that are ever-present in the environment,
    together with expert testimony reporting positive test results for the presence
    in the source ore used to manufacture the product. In the absence of evidence
    explaining how asbestos in the source ore would have been eliminated in the
    process of milling talc, that is enough to support more than a mere possibility
    that the accused product here, JBP, was a substantial factor in causing Doug
    Strobel to develop mesothelioma. Berg, by contrast, was a short-term use
    case in which the evidence tying the actual product the plaintiff used to the
    presence of asbestos in the product sold by the defendant during the exposure
    period was dubious. “The only basis on which to conclude that the samples
    tested were of the correct vintage was Berg’s testimony that the containers
    Fitzgerald tested looked like the ones he used.” (Berg, supra, 42 Cal.App.5th
    at p. 636.) Because of the evidence of long-term usage in this case, and
    because, as we explain below, Dr. Fitzgerald fairly draws the inference on
    this record that JBP of a vintage dating from within the exposure period
    contained asbestos, there is no such evidentiary gap in this case.
    2. The Trial Court’s Evidentiary Rulings
    In Lyons and in this case, the plaintiff relied on more than simply an
    inference from the use of asbestos-positive sources of raw talc. Dr. Fitzgerald
    23
    reported asbestos-positive tests of sample JBP that were “consistent with”
    the use of asbestos-contaminated raw talc. (Lyons, supra, 16 Cal.App.5th at
    p. 467.) J&J contends that, on this critical point, the Strobels offer nothing
    more than hearsay from Dr. Longo about which Dr. Fitzgerald lacks personal
    knowledge. This line of argument tracks the trial court’s reasoning. Without
    Dr. Longo’s hearsay opinion, the trial court ruled, the only evidence of
    asbestos in samples of JBP offered for retail sale comes from Dr. Fitzgerald’s
    testing of five canisters of JBP taken from J&J’s historical archives. But four
    of those five canisters date from periods in time before Doug Strobel was born
    in 1951, and for the only canister dating from after 1951, Dr. Fitzgerald
    reported no test results. As a result, the court ruled, a fair inference may be
    drawn that the only samples of JBP tested by Dr. Fitzgerald dating from
    within Doug Strobel’s lifetime tested negative for asbestos. In the absence of
    proof that the JBP actually marketed during the exposure period contained
    asbestos, according to the trial court, the Strobels were left with only
    inadmissible case-specific hearsay under Sanchez to establish exposure to an
    asbestos-containing product under Rutherford, supra, 
    16 Cal.4th 953
    .11 Here,
    too, we disagree.
    a. Standard of Review
    Trial courts always enjoy wide discretion to rule upon evidentiary
    objections. That is why most appellate courts apply an abuse of discretion
    11  J&J objected to Dr. Fitzgerald’s declaration—along with proffered
    testimony from all of the Strobels’ other experts—in part on lack of
    foundation grounds. As we read the trial court’s rulings on J&J’s evidentiary
    objections, the lack of foundation aspect of its exclusion of Dr. Fitzgerald’s
    proffered opinion rests on its Sanchez ruling, and nothing more. Beyond
    that, “it is not clear in what respect the trial court considered the foundation
    for Fitzgerald’s opinion to be lacking and any deficiency in that respect is not
    apparent.” (Lyons, supra, 16 Cal.App.5th at p. 468.)
    24
    standard of review to the trial court’s evidentiary rulings even in the context
    of a summary judgment motion. (Carnes v. Superior Court, supra,
    126 Cal.App.4th at p. 694.) But “[t]o determine if a court abused its
    discretion, we must consider ‘the legal principles and policies that should
    have guided the court’s actions.’ ” (Sargon Enterprises, Inc. v. University of
    Southern California (2012) 
    55 Cal.4th 747
    , 773 (Sargon).) “[T]he court’s
    discretion” to exclude expert testimony in particular “is not unlimited” where
    it implicates a party’s ability to present its case. (Ibid.) “Rather, it must be
    exercised within the confines of the applicable legal principles.” (Ibid.)
    Quoting from Reid v. Google, Inc. (2010) 
    50 Cal.4th 512
    , the Strobels
    urge us to review the trial court’s evidentiary rulings de novo because we are
    dealing with a paper record on summary judgment. (Id. at p. 535 [“ ‘Because
    summary judgment is decided entirely on the papers, and presents only a
    question of law, it affords very few occasions, if any, for truly discretionary
    rulings on questions of evidence. Nor is the trial court often, if ever, in a
    better position than a reviewing court to weigh the discretionary factors.’ ”].)
    But the language they rely upon merely quotes from the Court of Appeal’s
    superseded opinion in Reid. The Reid court expressly declined to reach the
    issue of “whether a trial court’s rulings on evidentiary objections based on
    papers alone in summary judgment proceedings are reviewed for abuse of
    discretion or reviewed de novo.” (Ibid.)
    We see no reason to take a step the Supreme Court has chosen not to
    take. But while we decline the Strobels’ invitation to announce a generally
    applicable de novo standard of review for evidentiary rulings on summary
    judgment, we think the procedural setting we have here justifies de novo
    review on this record. “ ‘The scope of [a trial court’s] discretion always
    resides in the particular law being applied, i.e., in the “legal principles
    25
    governing the subject of [the] action . . . .” ’ ” (Sargon, supra, 55 Cal.4th at
    p. 773.) Because the court’s rulings sustaining objections to the Strobels’
    expert testimony rest, fundamentally, on the legal premises it adopted in
    applying Sanchez, we will review these rulings independently.
    b. People v. Sanchez and its Recent Progeny
    “In Sanchez,” our Supreme Court “clarified the ‘proper application’ of
    our evidentiary law as it relates to the intersection of hearsay and expert
    testimony.” (People v. Veamatahau (2020) 
    9 Cal.5th 16
    , 25 (Veamatahau).)
    The Sanchez court begins its analysis by explaining that “[t]he hearsay rule
    has traditionally not barred an expert’s testimony regarding his general
    knowledge in his field of expertise.” (Sanchez, supra, 63 Cal.4th at p. 676.)
    That starting premise is crucial to a proper understanding of the Sanchez
    rule governing case-specific hearsay. Sanchez accommodates the pragmatic
    reality that, by dint of what experts do—they draw upon training in,
    experience with, and study of knowledge produced by others—this special
    category of witnesses must of necessity rely on hearsay sources.
    “Because experts rely on hearsay knowledge and because a jury ‘must
    independently evaluate the probative value of an expert’s testimony,’
    including by assessing the basis of the expert’s opinion, the expert is entitled
    to tell the jury the basis or ‘ “matter” upon which his opinion rests.’ ”
    (Veamatahau, supra, 9 Cal.5th at p. 25.) But rather than let an expert freely
    place before the fact finder any hearsay “matter” that may be characterized
    as a basis of his or her opinion so long as it is not admitted for the truth, the
    Sanchez court refined the rules governing admission of expert testimony to
    make clear that such testimony may convey hearsay only if it is (1) general
    knowledge among those in the expert’s field, or (2) independently provable by
    admissible evidence. (Sanchez, supra, 63 Cal.4th at pp. 676–677.)
    26
    Under Evidence Code sections 801, subdivision (b), and 802, Sanchez
    holds, not only can an expert “rely on hearsay in forming an opinion,” but he
    “may tell the jury in general terms that he did so.” (Sanchez, supra,
    63 Cal.4th at p. 685.) In so holding, Sanchez jettisons the need for the fact
    finder to recognize and maintain the elusive distinction between information
    coming from an expert that may be fully relied upon for the truth of contested
    facts, versus information that has been admitted for the limited purpose of
    evaluating the basis of the expert’s opinion. (People v. Nieves (2021)
    
    11 Cal.5th 404
    , 440 [“In Sanchez, we disapproved of the conclusion in prior
    decisions such as People v. Gardeley (1996) 
    14 Cal.4th 605
    , 618, that expert
    testimony about case-specific hearsay is not admitted for its truth and thus
    not subject to hearsay rules. (Sanchez, at p. 686, fn. 13.)”].)
    In place of the old, limited admissibility regime under the Gardeley line
    of cases, Sanchez restores the traditional common law distinction between
    inadmissible case-specific hearsay and admissible background knowledge.
    (Veamatahau, supra, 9 Cal.5th at p. 25.) After Sanchez, what was once
    known as “basis” testimony coming from experts is now handled as a
    threshold matter of admissibility, rather than by assigning different
    probative purposes to already admitted evidence. An expert’s testimony to
    background information is admissible—as it has always been, either as
    nonhearsay to the extent it rests on the expert’s personal knowledge (ibid.),
    or under a hearsay exception to the extent it rests on information provided by
    others (id. at pp. 25–26 & fn. 1)—while testimony to case-specific facts is
    subject to exclusion, unless independently proved by admissible evidence (id.
    at p. 26).
    “Case-specific facts are those relating to the particular events and
    participants alleged to have been involved in the case being tried.” (Sanchez,
    27
    supra, 63 Cal.4th at p. 676.) Two recent California Supreme Court cases—
    neither of which the trial court had the benefit of considering—elucidate the
    proper application of this concept. At issue in the first of these cases,
    Veamatahau, supra, 
    9 Cal.5th 16
    , was the admissibility of an expert opinion
    from a prosecution criminalist identifying pills found in the possession of the
    defendant as alprazolam. (Id. at p. 22.) The expert, a criminalist named
    Scott Rienhardt, “held a degree in ‘chemistry, with an emphasis in analytical
    chemistry[,]’ . . . had previously worked for the Drug Enforcement
    Administration,” and over the course of his career had tested for controlled
    substances thousands of times, and had identified alprazolam “ ‘hundreds’ of
    times.” (Ibid.) But despite his credentials as an analytical chemist,
    Rienhardt conducted no laboratory testing of the pills at issue. Instead, he
    matched the shape and markings on the pills to the images of pills in a
    database known as Ident-A-Drug. (Id. at pp. 23, 31.) On direct examination,
    Rienhardt testified that “it is standard practice to identify pharmaceutical
    pills by visual inspection, whereby one compares markings found on the pills
    against a database of imprints that the [FDA] requires to be placed on tablets
    containing controlled substances. He then testified that he performed this
    visual inspection on the pills seized from defendant and formed the opinion
    that they contained alprazolam.” (Id. at pp. 26–27.) Then, on cross-
    examination, he went further, testifying more specifically that the
    Ident-A-Drug database “ ‘tell[s] you’ ” that pills displaying a certain imprint
    “ ‘contain[] alprazolam, 2 milligrams.’ ” (Id. at p. 27.)
    Rienhardt’s visual match of the seized drugs to the markings for
    alprazolam in the database, the court held, was not hearsay at all because he
    personally did the matching, and to the extent he drew on the accumulated
    knowledge of others reflected in the database to draw his ultimate conclusion
    28
    identifying the seized drugs as alprazolam, that came within the hearsay
    exception for background knowledge. (Veamatahau, supra, 9 Cal.5th at
    p. 27.) As the court saw it, Rienhardt did nothing more than employ his
    expertise to gather pertinent information and selectively choose and apply a
    methodology commonly used by experts in his field for analysis. (Id. at p. 29.)
    The court rejected the argument that, by relying on the Ident-A-Drug
    database, Rienhardt’s ultimate conclusion merely conveyed to the jury the
    opinions of third parties. “Simply because the Ident-A-Drug Web site served
    as the basis for the expert’s ultimate opinion does not make information from
    the site case-specific,” the court observed. (Id. at p. 31.) “Information from
    the Ident-A-Drug database—that pills matching a certain description contain
    opioids—was hearsay but not case specific. It is no more case specific than if
    an expert divulged the equation—into which she entered the length of the
    skid marks she measured at the scene of the accident—to come to the
    conclusion that a defendant was traveling at the speed of 100 miles per hour
    before the crash.” (Ibid.)
    Resisting this conclusion, the defendant in Veamatahau contended that
    if an expert may simply consult a third-party source for his ultimate
    conclusion and convey that third party’s conclusion to the fact finder as
    background information, the trial court’s ability to vet the reliability of
    sources of third-party information “would be ‘undercut’ because the expert
    would be permitted to ‘essentially vouch for the reliability of a source.’ ”
    (Veamatahau, supra, 9 Cal.5th at p. 32.) This paints a “false dichotomy,” the
    court said. (Ibid.) Citing the backstop screening test for admissibility that
    trial courts must always undertake under the Evidence Code, the court
    explained that “[i]n fact, in law, and in practice, testimony admitted under
    section 801 or 802 [of the Evidence Code] is subject to scrutiny on reliability
    29
    grounds by the court and opposing counsel. Section 801 specifies that the
    ‘matter’ on which an expert relies must be ‘of a type that reasonably may be
    relied upon by an expert in forming an opinion upon the subject to which his
    testimony relates.’ ([Evid. Code,] § 801, subd. (b).) Thus, an expert must
    establish that the basis for his or her opinion is sufficiently reliable such that
    it ‘reasonably may be relied upon’ by experts testifying on the same subject.”
    (Veamatahau, at p. 32.)
    While Veamatahau illustrates the latitude experts are still given post-
    Sanchez to testify to background information relied upon in the formation of
    their opinions, a second Sanchez follow-on case, People v. Valencia (2021)
    
    11 Cal.5th 818
     (Valencia), shows how the rule barring case-specific hearsay
    places limits on that practice. Valencia affirms the exclusion of case-specific
    hearsay in a gang prosecution case. There, the defendant faced charges
    under the California Street Terrorism Enforcement and Prevention Act
    (STEP Act; Pen. Code, § 186.20 et seq.), a statute requiring the prosecution to
    prove, among other things, “a pattern of criminal gang activity” by the
    defendant or his gang associates. (Valencia, at pp. 828–829.) The defendant
    in Valencia was alleged to be a member of a gang known as Arvina 13. (Id. at
    p. 827.) To prove the requisite “pattern of criminal gang activity” by
    Arvina 13, Officer Ryan Calderon, an expert in gang activity, testified that
    members of Arvina 13 had committed certain predicate crimes on specified
    dates. (Ibid.)
    Appealing his conviction and sentencing enhancements imposed under
    the STEP Act, the defendant argued that Officer Calderon’s testimony was
    inadmissible case-specific hearsay under Sanchez. The California Supreme
    Court agreed and affirmed the reversal of the challenged conviction and
    sentence. (Valencia, supra, 11 Cal.5th at pp. 837–839, 841.) Picking up
    30
    where Veamatahau left off, the Valencia court further expounded upon the
    concept of background facts, as follows: “Hallmarks of background facts are
    that they are generally accepted by experts in their field of expertise, and
    that they will usually be applicable to all similar cases. Permitting experts to
    relate background hearsay information is analytically based on the safeguard
    of reliability. A level of reliability is provided when an expert lays foundation
    as to facts grounded in his or her expertise and generally accepted in that
    field.” (Id. at p. 836.) On the other hand, the court held, “if experts give
    testimony that goes beyond their own experience or beyond principles
    generally accepted in their field, the justifications for allowing greater
    evidentiary latitude cease to apply.” (Ibid.)
    The predicate crimes testimony from Officer Calderon did not pass this
    test. Sanchez itself acknowledges, by the use of a specific example involving
    gang prosecution, that “general testimony about a gang’s behavior, history,
    territory, and general operations is usually admissible. (See Sanchez, supra,
    63 Cal.4th at p. 698.) The same is true of the gang’s name, symbols, and
    colors. All this background information can be admitted through an expert’s
    testimony, even if hearsay, if there is evidence that it is considered reliable
    and accurate by experts on the gang.” (Valencia, supra, 11 Cal.5th at p. 838.)
    Officer Calderon’s testimony about predicate crimes committed by Arvina 13
    members—which was based on nothing more than “conversations with other
    officers and a review of police reports” (id. at p. 827)—had no such foundation
    in specialized knowledge generally accepted in his field or otherwise
    grounded in his expertise. “The proper role of expert testimony,” the court
    held, “is to help the jury understand the significance of case-specific facts
    31
    proven by competent evidence, not to place before the jury otherwise
    unsubstantiated assertions of fact.” (Id. at p. 837.)12
    c. Dr. Fitzgerald’s Opinion
    J&J’s summary judgment motion took a rifle-shot approach to the
    evidence of causation in this case, primarily targeting the reliance the
    Strobels’ experts placed on Dr. Longo’s positive tests for asbestos in JBP.
    J&J objected on various grounds to the opinions offered by all of the Strobels’
    experts, but the principal focus of these objections—and most of the parties’
    attention in their appellate briefs—is on Dr. Fitzgerald’s opinion.13 “[O]nly
    with the particular facts of Longo’s testing in evidence,” J&J argues, could
    Dr. Fitzgerald “add general background knowledge to opine on their
    significance” in a way that is permissible under Sanchez. “Fitzgerald did not
    merely mention Longo without explanation on a list of reference materials,”
    J&J argues. He “spelled out Longo’s finding of asbestos contamination in 18
    particular containers of JBP” and other J&J talcum powder.
    12  The parties discuss two STEP Act cases applying Sanchez (People v.
    Bermudez (2020) 
    45 Cal.App.5th 358
    , disapproved in Valencia, supra,
    11 Cal.5th at p. 839, fn. 17; and our decision in People v. Thompkins (2020)
    
    50 Cal.App.5th 365
    ), with the Strobels relying on Bermudez and
    distinguishing Thompkins, and J&J relying on Thompkins and
    distinguishing Bermudez. Bermudez and Thompkins represent two sides in a
    split of appellate authority that was resolved in Valencia. (Valencia, at
    p. 839, fn. 17.) In light of Valencia, we need not address either case.
    13J&J claims the Strobels do not contest the trial court’s evidentiary
    rulings with respect to Drs. Cohen and Finkelstein and Mr. Ay. That is not
    how we read the record. The title of the principal section in the Strobels’
    opening brief addressing the court’s evidentiary rulings focuses on the
    exclusion of “[e]xpert [t]estimony,” and is not directed solely to Dr. Fitzgerald.
    And neither is the substance of the argument presented in this section of the
    opening brief limited to Dr. Fitzgerald. We therefore address the trial court’s
    evidentiary rulings pertaining to Drs. Cohen and Finkelstein and Mr. Ay
    below in part II.B.2.d.
    32
    With J&J, we agree the trial court was correct to rule that
    Dr. Fitzgerald’s opinion is inadmissible case-specific hearsay “to the extent
    that” he relates the specifics of Dr. Longo’s testing data and results.
    Dr. Fitzgerald’s reliance on Dr. Longo cannot be analogized to the
    criminalist’s use of a database built from an FDA-approved drug
    classification system and generally used by forensic experts. It has long been
    settled that an expert may not simply repeat a third party’s opinion and offer
    it up as confirmatory of his own. (Whitfield v. Roth (1974) 
    10 Cal.3d 874
    , 895
    [“doctors can testify as to the basis of their opinion [citation], but this is not
    intended to be a channel by which testifying doctors can place the opinion of
    innumerable out-of-court doctors before the jury”]; People v. Campos (1995)
    
    32 Cal.App.4th 304
    , 308 [“An expert witness may not, on direct examination,
    reveal the content of reports prepared or opinions expressed by nontestifying
    experts.”].) The Strobels argue that even if Dr. Fitzgerald’s reliance on the
    conclusion Dr. Longo drew from his testing JBP samples is inadmissible, his
    reliance on the underlying testing data and photographs used by Dr. Longo is
    properly admissible. We do not see this as a meaningful distinction. The
    specifics Dr. Fitzgerald presents from Dr. Longo’s lab work—the numbers of
    samples that were positive for asbestos, and the numbers of asbestiform
    structures in those samples—simply report his results and thus
    impermissibly put before the finder of fact Dr. Longo’s conclusion by proxy
    (see Sanchez, supra, 63 Cal.4th at p. 685 [expert may rely on case-specific
    hearsay in forming his opinion and “tell the jury in general terms that he did
    so”]), and Dr. Fitzgerald offers no independent interpretation of this
    information.
    While the cases announcing this prohibition on rote repetition of the
    opinions of others predate Sanchez, we think the rule they enunciate remains
    33
    vital post-Sanchez. An absent witness’s opinion may not be smuggled into
    evidence through an expert by dressing it up as background information.
    Veamatahau explains, as does Valencia, that background evidence must be
    generally relied upon by experts in the witnesses’ field of expertise. While
    there may be situations where a much-published but absent expert whose
    views are well accepted in a particular field are repeated by a testifying
    expert to establish the premises of a proffered expert opinion, this is not one
    of them. The Strobels make no showing that Dr. Longo has published
    anything or that his work is generally relied upon by others. For
    Dr. Fitzgerald to testify that Dr. Longo detected specific quantities of
    asbestiform fibers in JBP samples dating from within the exposure period is
    no different, we think, than Officer Calderon testifying to the content of
    police reports to establish the historical fact that gang crimes were
    committed by members of Arvina 13 on specific dates in Valencia.
    That does not end the inquiry, however. In its zeal to attack what it
    characterizes repeatedly as Dr. Longo’s “made-for-litigation” testing results,
    J&J fails to account for the full breadth of the evidence the Strobels put
    forward in opposition to summary judgment. Both Dr. Sanchez and
    Dr. Fitzgerald selected and drew upon various published materials from
    government agencies and professional standard-setting groups,14 published
    Dr. Fitzgerald—EPA; FDA; International Mineralogical Association;
    14
    United States Geological Survey; Vermont Geological Survey. Dr. Sanchez—
    American Society for Testing and Materials; Chinese Pharmacopoeia;
    Cosmetic, Toiletry, and Fragrance Association; EPA; FDA; International
    Agency for Research on Cancer; International Organization for
    Standardization; U.S. Pharmacopeial Convention Talc Expert Panel.
    34
    academic articles,15 published reports of “historical” testing,16 as well as
    testing data from their own labs. Dr. Fitzgerald and Dr. Sanchez disagree on
    the best tools to use for the detection of asbestos (TEM plus SAED and either
    or both of XRD and EDX [Dr. Fitzgerald], or XRD and PLM [Dr. Sanchez]),
    but both agree on what to look for: Asbestiform materials of a specific type—
    anthophyllite, tremolite or chrysotile. They draw different conclusions about
    whether the offending asbestiform minerals may be found in JBP, owing
    largely to their different views of the proper methods for counting asbestiform
    structures in tested samples of talc source ore and milled product. But this
    dispute cannot be resolved on summary judgment by focusing exclusively on
    whether there was direct evidence of asbestos in milled JBP during the
    exposure period.
    Even without Dr. Longo’s testing data and results, we are satisfied that
    Dr. Fitzgerald formulated his opinion based upon principles generally
    accepted in his area of expertise and that he applied those principles upon a
    proper evidentiary foundation. Ultimately, the exposure issue in this case
    will turn on principles of geology, mineralogy and asbestos testing.
    Dr. Fitzgerald, a geologist with special expertise in asbestos detection, traced
    asbestiform minerals from the sources of raw talc J&J used to manufacture
    15 Dr. Fitzgerald—e.g., Deer, Howie, and Zussman (1962); Groppo and
    Compagnoni (2007); Hawthorne (2012); Lollino (2004); McCarthy (2006);
    Newman (1995); Peretti (1966); Rohl and Langer (1974); Sandrone and
    Zucchetti (1988); Shultz and Williams (1942); Van Gosen (2004); Webber
    (1998). Dr. Sanchez—e.g., Blount (1991); Boundy (1979); Chidester (1951,
    1964); Coggiola (2003); Li (1999); McCrone (1977); Pooley (1972); Rubino
    (1976); Sandrone and Zucchetti (1988); Wang (2003, 2006); Yan (2003).
    16Dr. Fitzgerald—Colorado School of Mines (1971); Gail (1979); Johns
    Manville (1973); Lewin (1972); McCrone (1971); Pooley (1972); Shultz and
    Williams (1942). Dr. Sanchez—Buzon (2016); Eiermann (1976); Lewin
    (1973).
    35
    JBP to the JBP Doug Strobel used. In doing so, he drew inferences from a
    wide variety of data sources. For example, Dr. Fitzgerald cites and relies on
    a 1972 FDA-sponsored study by Professor Seymour Lewin of New York
    University (the NYU Study) examining “195 standard, commercial cosmetic
    talc products,” many of which he found to “contain[] detectable amounts of
    asbestiform minerals,” as well as a 1976 article published by A.N. Rohl and
    A.M. Langer (Rohl & Langer) reporting on the testing of 20 consumer
    products labeled as talc or talcum powder, including body powders and baby
    powders.17 Of the 20 product tests reported in Rohl & Langer, according to
    Dr. Fitzgerald, 10 found detectable amounts of tremolite and anthophyllite,
    principally asbestiform.18 In addition to the NYU Study and Rohl & Langer,
    17 It seems clear that Dr. Fitzgerald drew upon his knowledge as an
    asbestos testing expert in selecting these third-party source documents for
    their pertinence to his opinion. Consider, for example, his discussion of why
    the electron microscopy testing methodology that generated the results
    reported in Rohl & Langer was, in his view, superior to older light microscopy
    techniques. “The authors noted that while some asbestos was resolvable by
    light microscopy, most samples were too fine-grained, with particle
    dimensions [too] small for light microscopy, and that ‘naturally occurring
    asbestiform minerals often lie below the working resolution capabilities of
    light microscope’. They further noted that by comparing the results of optical
    microscopy and quantitative XRD with those from TEM analysis they
    observed that large numbers of fibers could go undetected by the less
    sensitive techniques. Both asbestiform anthophyllite and asbestiform
    tremolite were found in that testing of cosmetic talcum powder, with the
    anthophyllite described as having greater length to width (aspect) ratios than
    the tremolite asbestos. Furthermore, the anthophyllite asbestos
    concentration was reported as 4 to 5 times that of the asbestiform tremolite
    in that product, as tested and reported over 40 years ago.”
    18Dr. Sanchez claims that the FDA later disclaimed these positive
    findings for asbestos based on follow-up “light microscopy and differential
    thermal analysis” testing. But Dr. Fitzgerald disagrees that the FDA’s
    follow-up testing undercut Professor Lewin’s original findings. Among
    36
    Dr. Fitzgerald also relies on the FDA’s reported findings in 2019 of JBP
    manufactured from Chinese talc (the 2019 FDA Report).
    The trial court seems to have been aware that Dr. Longo’s testing was
    not the sole source of third-party information relied upon by Dr. Fitzgerald,
    because, after concluding Dr. Fitzgerald’s reliance on Dr. Longo was
    inadmissible under Sanchez, the court went on to emphasize in vague terms
    that its ruling on this point embraced other third-party documents as well.
    Without discussing, identifying or analyzing any of these documents, the trial
    court ruled that they were all inadmissible case-specific hearsay. Some of the
    third-party source material relied upon by both Dr. Fitzgerald and
    Dr. Sanchez may well be excludable on hearsay grounds when offered at
    trial.19 But even assuming the court’s broad-brush treatment of the “various
    several reasons Dr. Fitzgerald gives for disagreeing with Dr. Sanchez on this
    point is that the FDA did not use electron microscopy. As evidence offered by
    the nonmoving party in opposition to summary judgment, Dr. Fitzgerald’s
    take on the NYU Study must be credited over that of Dr. Sanchez, at least at
    this stage of the proceedings.
    19 For example, in a discussion of talc ore from a mine in Vermont
    known as the Johnson Mine, Dr. Fitzgerald cites deposition testimony in
    other litigation from Dr. Glen Hemstock as well as a series of documents
    “pertaining to testing of Emtal ore, talc and plant facilities in the mid-to-late
    1970s that detected the presence of asbestos . . . .” Dr. Hemstock’s deposition
    testimony appears to be objectionable for the same reasons Dr. Longo’s
    testimony in other litigation is objectionable. There is also no indication that
    any of the Johnson Mine testing reports cited by Dr. Fitzgerald were
    published or subjected to any other form of peer review.
    Dr. Sanchez, for his part, cites testing of Vermont talc ore by “McCrone
    Laboratories, RJ Lee Group, and other third-party testers comprising test
    results covering J&J’s talcum powder for the past 40+ years.” Dr. Sanchez’s
    testimony regarding testing by RJ Lee Group may be proper if he has
    personal knowledge of it, but like Dr. Fitzgerald’s reference to testing of ore
    from the Emtal mine, there is no indication that any of the third-party
    37
    documents from third parties” cited by Dr. Fitzgerald qualifies as a clear
    enough exclusionary ruling to warrant treatment as a basis for the summary
    judgment ruling before us, we think the court erred in ruling that all of the
    third-party documents relied upon by Dr. Fitzgerald are inadmissible case-
    specific hearsay and therefore excludable along with the proxy opinion from
    Dr. Longo. Granted, some of the third-party documents Dr. Fitzgerald relies
    upon are specific to the defendant (J&J) and to the accused product (JBP) in
    this case, but that alone does not make them case-specific hearsay, since, as
    the Veamatahau court pointed out, experts may always testify to ultimate
    facts. (Evid. Code, § 805; Veamatahau, supra, 9 Cal.5th at p. 27.)
    Rather, what is important is that the third-party documents chosen by
    Dr. Fitzgerald qualify as source material that may be reasonably relied upon
    by those in his field of expertise. (Veamatahau, supra, 9 Cal.5th at p. 27.)
    Particularly when Dr. Fitzgerald’s declaration is read as a whole, we see
    nothing in his proffered testimony to suggest that he is relying on “ ‘matter’ ”
    that cannot be deemed “sufficiently reliable such that it ‘reasonably may be
    relied upon’ by experts testifying on the same subject.” (Evid. Code, § 801,
    subd. (b); Veamatahau, at p. 32.) J&J’s own expert, Dr. Sanchez, proffers an
    opinion based on a “review of various governmental and academic studies on
    talc sourced from Val Chisone/Val Germanasca, Italy, southern Vermont, and
    Guangxi, China.” He even cites and discusses some of the same source
    materials Dr. Fitzgerald cites. Because—apart from Dr. Longo’s test
    results—most of the background material relied upon by Dr. Sanchez is
    testing to which Dr. Sanchez makes general reference was personally known
    to him, published or otherwise subjected to some form of peer review.
    We take no view of whether, on appropriate objection at trial, any of
    the third-party sources relied upon by Drs. Fitzgerald or Sanchez may be
    excludable on hearsay or other grounds, in whole or in part.
    38
    generically comparable to the background information Dr. Fitzgerald relies
    upon, we think J&J has implicitly confirmed the reliability of Dr. Fitzgerald’s
    sources by endorsing Dr. Sanchez’s reliance on sources of the same general
    type.
    J&J attempts to argue that, without Dr. Longo’s testing results,
    Dr. Fitzgerald’s opinion rests on “ ‘ “assumptions of fact without evidentiary
    support” ’ ” (Sargon, supra, 55 Cal.4th at p. 770) and is therefore inadmissible
    as speculative under Sargon. We cannot agree. Dr. Fitzgerald traces
    asbestos contamination from mined talc ore to milled JBP, drawing
    inferences from a variety of data sources, including published papers,
    government reports, internal J&J documents, testing of source ore by
    Dr. Compton, as well as Dr. Fitzgerald’s own testing of archival J&J samples
    of JBP. J&J has many points of disagreement with Dr. Fitzgerald, but none
    exposes an “ ‘analytical gap between the data and the opinion proffered’ ” that
    is “ ‘simply too great’ ” to be countenanced. (Sargon, at p. 771.) Under
    Sargon, the trial court “does not resolve scientific controversies.” (Id. at
    p. 772.) “Rather, it conducts a ‘circumscribed inquiry’ to ‘determine whether,
    as a matter of logic, the studies and other information cited by experts
    adequately support the conclusion that the expert’s general theory or
    technique is valid.’ ” (Ibid.)
    J&J argues there is a fatal gap in Dr. Fitzgerald’s logic—and hence in
    the Strobels’ proof—because he reported positive tests for asbestos in archival
    samples of JBP though the 1940’s, yet produced no such report for any
    sample during Doug Strobel’s lifetime. We are not convinced this feature of
    Dr. Fitzgerald’s opinion can bear the weight J&J places on it. Dr. Fitzgerald
    confirmed through his own testing that there is asbestos contamination in
    archival samples of JBP dating from the late 1940’s, which is consistent with
    39
    testing on samples of source ore from the Val Chisone and Val Germanasca
    region conducted by him and by Dr. Compton.20 It is reasonable to infer from
    these tests of Italian source ore that this contamination was still present in
    JBP at least through 1968, when J&J shifted its sourcing of talc ore from
    Italy to Vermont. And in light of the 2019 FDA Report, the NYU Study, and
    Rohl & Langer, it seems fair to draw the further inference that asbestos was
    present in JBP throughout the entire exposure period. Drawing the opposite
    inference in favor of J&J, as the trial court did—based on a negative
    inference that there is no proof of asbestos in JBP after 1951 based on the
    absence of any positive asbestos test in archival samples from J&J post-
    dating Doug Strobel’s birth—violates the fundamental rule that we must
    construe the evidence liberally for the nonmoving party.
    20 J&J argues that Dr. Compton’s testing approach, if scrutinized
    properly, cannot be accepted as reliable for admissibility purposes because it
    is not based upon “a methodology generally accepted in the scientific
    community for identifying asbestos in cosmetic talc.” Dr. Compton’s “TEM
    methodology . . . used to count ‘structures,’ ” J&J points out, “could not
    distinguish an asbestos fiber from nonasbestiform particles.” In support of
    this contention—a line of attack which, notably, J&J does not pursue with
    respect to Dr. Fitzgerald (except to the extent Dr. Fitzgerald relies on
    Dr. Longo)—J&J cites the Kelly test, an evidentiary screening tool designed
    to test the reliability of novel methods of scientific proof for general
    acceptance within the relevant scientific community. (People v. Kelly (1976)
    
    17 Cal.3d 24
    , 30–31; see People v. Azcona (2020) 
    58 Cal.App.5th 504
    , 510
    [“General acceptance means ‘a consensus drawn from a typical cross-section
    of the relevant, qualified scientific community.’ ”].) This was not the basis for
    the trial court’s exclusion of any of the Strobels’ expert testimony. We
    therefore have no occasion to address the potential applicability of the Kelly
    test or how that test may relate to reliability testing for purposes of Sanchez,
    except to point out that both sides’ proffered expert testimony may be subject
    to further screening at trial, including through an Evidence Code section 802
    hearing should the trial court deem it appropriate to hold such a hearing.
    40
    J&J insists it is sheer conjecture to infer the presence of asbestiform
    minerals in JBP from nothing more than the presence of these minerals in
    talc ore used to manufacture JBP. Pointing to its own evidence, J&J claims
    it “maintains the industry’s highest standards for the talc it uses to
    manufacture its talcum powder products, including JBP”; its “[c]osmetic talc
    is selectively mined, and talc ore is carefully sorted at different stages”; and
    that “only about 5% of mined talc is selected for use as cosmetic talc.” J&J
    also extols the “purity” of its “talc ore”, emphasizes that finding talc ore
    accessory minerals in asbestiform habit is “rare”—occurring in less than
    1 percent of the known occurrence of each mineral—and claims it “has long
    conducted a regular monitoring program to test its talc supply using methods
    that exceed industry and regulatory standards to confirm the talc is not
    contaminated with asbestos.” Dr. Sanchez, whose opinion J&J principally
    relied upon and the trial court accepted on summary judgment, pointed to no
    evidence demonstrating that J&J’s sorting, screening and selectivity
    processes are capable of weeding out from raw talc submicron-size
    asbestiform particles or that it is even possible to achieve such “purity.” But
    we acknowledge that these arguments could ultimately prevail at trial.
    Although we would not describe the Strobels’ summary judgment showing on
    legal causation as overwhelming, we see ample circumstantial evidentiary
    support for the inference Dr. Fitzgerald draws that asbestos contamination
    was persistently present in JBP throughout the exposure period.
    d. The Opinions of Drs. Cohen and Finkelstein and Mr. Ay
    Turning, finally, to the trial court’s rulings that the opinions from
    Dr. Cohen, Dr. Finkelstein and Mr. Ay were inadmissible “to the extent” they
    rely on Dr. Longo and other third-party sources of information concerning
    whether JBP contained asbestos during the time Doug Strobel used it, we
    conclude that those rulings were correct. Dr. Cohen and Dr. Finkelstein
    41
    show considerable familiarity with geology, mineralogy and asbestos testing,
    but neither of them purports to be an expert in these areas. And while
    Mr. Ay has some familiarity with asbestos testing, he has none in geology
    and mineralogy or asbestos exposure from nonoccupational sources. Thus,
    the trial court was within its discretion to rule that none of these witnesses is
    competent to give testimony about the presence of asbestos in JBP. For any
    of them to pass along third-party geological and mineralogical opinions
    outside the ambit of their areas of expertise—without the qualifications
    necessary to gauge the reliability of the information, and without any
    independent ability to build upon it in formulating their own opinions—
    amounts to allowing them to channel someone else’s views to the fact finder.
    That has never been allowed (Whitfield v. Roth, supra, 10 Cal.3d at p. 895),
    and is still not allowed, as Valencia illustrates. (See Valencia, supra,
    11 Cal.5th at pp. 826, 836–840.)
    Our holding with respect to Dr. Cohen, Dr. Finkelstein and Mr. Ay
    should not be read to mean that, at trial, they may be barred from
    mentioning the presence of asbestos in JBP, or the geology, mineralogy or
    asbestos testing issues pertinent to that issue. Within their own ambits of
    expertise, Dr. Cohen, Dr. Finkelstein and Mr. Ay each proffers an opinion
    that is relevant to the ultimate question under Rutherford whether, taking
    into account “the length, frequency, proximity and intensity of exposure, the
    peculiar properties of [JBP], any other potential causes to which the disease
    could be attributed,” along with other factors bearing on comparative fault,
    Doug Strobel’s “inhalation of fibers from [JBP] [may] be deemed a
    ‘substantial factor’ in causing [his] cancer.” (Rutherford, supra, 16 Cal.4th at
    p. 975.) Because there is likely to be some subject matter overlap in the
    opinions offered by all of the Strobels’ causation experts, it should be kept in
    42
    mind that, for any expert relying on another expert outside his area of
    expertise, the “distinction between generally accepted background
    information and the supplying of case-specific facts is honored by the use of
    hypothetical questions. ‘Using this technique,’ . . . [a]n examiner may ask an
    expert to assume a certain set of case-specific facts for which there is
    independent competent evidence, then ask the expert what conclusions the
    expert would draw from those assumed facts.” (Sanchez, supra, 63 Cal.4th at
    pp. 676–677.) Upon properly structured hypothetical questions, therefore,
    Dr. Cohen, Dr. Finkelstein and Mr. Ay may be asked to assume the truth of
    Dr. Fitzgerald’s view that JBP contained asbestos during the years Doug
    Strobel used it, or any of the bases for his opinion, and on that foundation, to
    offer their own opinions upon the closely related epidemiological, toxicological
    or occupational health questions the finder of fact may be called upon to
    address in resolving the broader issue of legal causation.
    III. DISPOSITION
    The order granting summary judgment and the judgment entered upon
    it are reversed and the cause is remanded for further proceedings consistent
    with this opinion. Jo Ann Strobel, prevailing appellant, shall recover the
    Strobels’ costs on appeal.
    STREETER, Acting P. J.
    WE CONCUR:
    TUCHER, J.*
    BROWN, J.
    *Presiding Justice of the Court of Appeal, First Appellate District,
    Division Three, sitting by assignment pursuant to article VI, section 6 of the
    California Constitution.
    43
    Trial Court: Solano County Superior Court
    Trial Judge: Hon. Wendy G. Getty
    Counsel:    Brayton Purcell, Gilbert L. Purcell, Richard M. Grant,
    Steven J. Patti, Christine A. Renken,
    for Plaintiff and Appellant.
    King & Spalding, Paul R. Johnson, Alexander G. Calfo,
    Susan V. Vargas, Stacy L. Foster; Orrick Herrington &
    Sutcliffe, Robert M. Loeb, pro hac vice, Nathan Dullum,
    for Defendants and Respondents.
    A159609