California Civil Jury Instructions (CACI) (2017)

435. Causation for Asbestos-Related Cancer Claims

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435.Causation for Asbestos-Related Cancer Claims
A substantial factor in causing harm is a factor that a reasonable person
would consider to have contributed to the harm. It does not have to be
the only cause of the harm.
[Name of plaintiff] may prove that exposure to asbestos from [name of
defendant]’s product was a substantial factor causing [his/her/[name of
decedent]’s] illness by showing, through expert testimony, that there is a
reasonable medical probability that the exposure was a substantial
factor contributing to [his/her] risk of developing cancer.
New September 2003; Revised December 2007
Directions for Use
If the issue of medical causation is tried separately, revise this instruction to focus
on that issue.
If necessary, CACI No. 431, Causation: Multiple Causes, may also be given.
Unless there are other defendants who are not asbestos manufacturers or suppliers,
do not give CACI No. 430, Causation: Substantial Factor.
Sources and Authority
• “In the context of a cause of action for asbestos-related latent injuries, the
plaintiff must first establish some threshold exposure to the defendant’s
defective asbestos-containing products, and must further establish in reasonable
medical probability that a particular exposure or series of exposures was a
‘legal cause’ of his injury, i.e., a substantial factor in bringing about the injury.
In an asbestos-related cancer case, the plaintiff need not prove that fibers from
the defendant’s product were the ones, or among the ones, that actually began
the process of malignant cellular growth. Instead, the plaintiff may meet the
burden of proving that exposure to defendant’s product was a substantial factor
causing the illness by showing that in reasonable medical probability it was a
substantial factor contributing to the plaintiff’s or decedent’s risk of developing
cancer. The jury should be so instructed. The standard instructions on
substantial factor and concurrent causation remain correct in this context and
should also be given.” (Rutherford v. Owens-Illinois, Inc. (1997) 16 Cal.4th 953,
982–983 [67 Cal.Rptr.2d 16, 941 P.2d 1203], original italics, internal citation
and footnotes omitted.)
• “The term ‘substantial factor’ has not been judicially defined with specificity,
and indeed it has been observed that it is ‘neither possible nor desirable to
reduce it to any lower terms.’ This court has suggested that a force which plays
only an ‘infinitesimal’ or ‘theoretical’ part in bringing about injury, damage, or
loss is not a substantial factor. Undue emphasis should not be placed on the
term ‘substantial.’ For example, the substantial factor standard, formulated to
aid plaintiffs as a broader rule of causality than the ‘but for’ test, has been
invoked by defendants whose conduct is clearly a ‘but for’ cause of plaintiff’s
injury but is nevertheless urged as an insubstantial contribution to the injury.
Misused in this way, the substantial factor test ‘undermines the principles of
comparative negligence, under which a party is responsible for his or her share
of negligence and the harm caused thereby.’ ” (Rutherford, supra, 16 Cal.4th at
p. 969, internal citations omitted.)
• “[A] very minor force that does cause harm is a substantial factor. This rule
honors the principle of comparative fault.” (Bockrath v. Aldrich Chem. Co.
(1999) 21 Cal.4th 71, 79 [86 Cal.Rptr.2d 846, 980 P.2d 398], internal citation
• “Contrary to defendant’s assertion, the California Supreme Court’s decision in
Viner v. Sweet (2003) 30 Cal.4th 1232 [135 Cal.Rptr.2d 629, 70 P.3d 1046]
(Viner) did not alter the causation requirement in asbestos-related cases. In
Viner, the court noted that subsection (1) of section 432 of the Restatement
Second of Torts, which provides that ‘the actor’s negligent conduct is not a
substantial factor in bringing about harm to another if the harm would have
been sustained even if the actor had not been negligent,’ ‘demonstrates how the
“substantial factor” test subsumes the traditional “but for” test of causation.’
Defendant argues that Viner required plaintiffs to show that defendant’s product
‘independently caused [plaintiff’s] injury or that, but for that exposure,
[plaintiff] would not have contracted lung cancer.’ Viner, however, is a legal
malpractice case. It does not address the explicit holding in Rutherford that
‘plaintiffs may prove causation in asbestos-related cancer cases by
demonstrating that the plaintiff’s exposure to defendant’s asbestos-containing
product in reasonable medical probability was a substantial factor in
contributing to the aggregate dose of asbestos the plaintiff or decedent inhaled
or ingested, and hence to the risk of developing asbestos-related cancer, without
the need to demonstrate that fibers from the defendant’s particular product were
the ones, or among the ones, that actually produced the malignant growth.’ ”
Viner is consistent with Rutherford insofar as Rutherford requires proof that an
individual asbestos-containing product is a substantial factor contributing to the
plaintiff’s risk or probability of developing cancer.” (Jones v. John Crane, Inc.
(2005) 132 Cal.App.4th 990, 998, fn. 3 [35 Cal.Rptr.3d 144], internal citations
• “ ‘A threshold issue in asbestos litigation is exposure to the defendant’s
product. . . . If there has been no exposure, there is no causation.’ Plaintiffs
bear the burden of ‘demonstrating that exposure to [defendant’s] asbestos
products was, in reasonable medical probability, a substantial factor in causing
or contributing to [plaintiff’s] risk of developing cancer.’ ‘Factors relevant to
assessing whether such a medical probability exists include frequency of
exposure, regularity of exposure and proximity of the asbestos product to
[plaintiff].’ Therefore, ‘[plaintiffs] cannot prevail against [defendant] without
evidence that [plaintiff] was exposed to asbestos-containing materials
manufactured or furnished by [defendant] with enough frequency and regularity
as to show a reasonable medical probability that this exposure was a factor in
causing the plaintiff’s injuries.’ ” (Whitmire v. Ingersoll-Rand Co. (2010) 184
Cal.App.4th 1078, 1084 [109 Cal.Rptr.3d 371], internal citations omitted.)
• “Further, ‘[t]he mere “possibility” of exposure’ is insufficient to establish
causation. ‘[P]roof that raises mere speculation, suspicion, surmise, guess or
conjecture is not enough to sustain [the plaintiff’s] burden’ of persuasion.” (Izell
v. Union Carbide Corp. (2014) 231 Cal.App.4th 962, 969 [180 Cal.Rptr.3d
382], internal citations omitted.)
• “To support an allocation of liability to another party in an asbestos case, a
defendant must ‘present evidence that the aggregate dose of asbestos particles
arising from’ exposure to that party’s asbestos ‘constituted a substantial factor in
the causation of [the decedent’s] cancer.’ ” (Soto v. BorgWarner Morse TEC Inc.
(2015) 239 Cal.App.4th 165, 205 [191 Cal.Rptr.3d 263].)
• “ ‘[G]iven the long latency period of asbestos-related disease, and the
occupational settings that commonly exposed the worker to multiple forms and
brands of asbestos products with varying degrees of toxicity,’ our Supreme
Court has held that a plaintiff ‘need not prove with medical exactitude that
fibers from a particular defendant’s asbestos-containing products were those, or
among those, that actually began the cellular process of malignancy.’ Rather, a
‘plaintiff may meet the burden of proving that exposure to defendant’s product
was a substantial factor causing the illness by showing that in reasonable
medical probability it was a substantial factor contributing to the plaintiff’s or
decedent’s risk of developing cancer.’ ” (Izell, supra, 231 Cal.App.4th at p. 975,
original italics, internal citation omitted.)
• “Many factors are relevant in assessing the medical probability that an exposure
contributed to plaintiff’s asbestos disease. Frequency of exposure, regularity of
exposure, and proximity of the asbestos product to plaintiff are certainly
relevant, although these considerations should not be determinative in every
case. [Citation.] Additional factors may also be significant in individual cases,
such as the type of asbestos product to which plaintiff was exposed, the type of
injury suffered by plaintiff, and other possible sources of plaintiff’s injury.
[Citations.] ‘Ultimately, the sufficiency of the evidence of causation will depend
on the unique circumstances of each case.’ [Citation.]” (Paulus v. Crane Co.
(2014) 224 Cal.App.4th 1357, 1363–1364 [169 Cal.Rptr.3d 373].)
• “In this case, [defendant] argues the trial court’s refusal to give its proposed
instruction was error because the instruction set forth ‘the requirement in
Rutherford that causation be decided by taking into account “the length,
frequency, proximity and intensity of exposure, the peculiar properties of the
individual product, [and] any other potential causes to which the disease could
be attributed.” ’ But Rutherford does not require the jury to take these factors
into account when deciding whether a plaintiff’s exposure to an asbestos-
containing product was a substantial factor in causing mesothelioma. Instead,
those factors are ones that a medical expert may rely upon in forming his or her
expert medical opinion.” (Davis v. Honeywell Internat. Inc. (2016) 245
Cal.App.4th 477, 495 [199 Cal.Rptr.3d 583], internal citation omitted.)
• “Mere presence at a site where asbestos was present is insufficient to establish
legally significant asbestos exposure.” (Shiffer v. CBS Corp. (2015) 240
Cal.App.4th 246, 252 [192 Cal.Rptr.3d 346].)
• “We disagree with the trial court’s view that Rutherford mandates that a medical
doctor must expressly link together the evidence of substantial factor causation.
The Rutherford court did not create a requirement that specific words must be
recited by appellant’s expert. Nor did the Rutherford court specify that the
testifying expert in asbestos cases must always be ‘somebody with an M.D.
after his name.’ The Rutherford court agreed with the Lineaweaver court that
‘the reference to “medical probability” in the standard “is no more than a
recognition that asbestos injury cases (like medical malpractice cases) involve
the use of medical evidence.” [Citation.]’ The Supreme Court has since clarified
that medical evidence does not necessarily have to be provided by a medical
doctor.” (Hernandez v. Amcord, Inc. (2013) 215 Cal.App.4th 659, 675 [156
Cal.Rptr.3d 90], internal citations omitted.)
• “Nothing in Rutherford precludes a plaintiff from establishing legal causation
through opinion testimony by a competent medical expert to the effect that
every exposure to respirable asbestos contributes to the risk of developing
mesothelioma. On the contrary, Rutherford acknowledges the scientific debate
between the ‘every exposure’ and ‘insignificant exposure’ camps, and recognizes
that the conflict is one for the jury to resolve.” (Izell, supra, 231 Cal.App.4th at
p. 977.)
• “Nor is there a requirement that ‘specific words must be recited by [plaintiffs’]
expert.’ [¶] The connection, however, must be made between the defendant’s
asbestos products and the risk of developing mesothelioma suffered by the
decedent.” (Paulus,supra, 224 Cal.App.4th at p. 1364.)
Secondary Sources
3 Witkin, California Procedure (5th ed. 2008) Actions, § 570
Haning et al., California Practice Guide: Personal Injury, Ch. 2(II)-D, Theories of
Recovery—Strict Liability For Defective Products, ¶ 2:1259 (The Rutter Group)
Haning et al., California Practice Guide: Personal Injury, Ch. 2(II)-O, Theories of
Recovery—Causation Issues, ¶ 2:2409 (The Rutter Group)
1 Levy et al., California Torts, Ch. 2, Causation, § 2.03 (Matthew Bender)
California Products Liability Actions, Ch. 2, Liability for Defective Products,
§ 2.22, Ch. 7, Proof, § 7.06 (Matthew Bender)
33 California Forms of Pleading and Practice, Ch. 380, Negligence, § 380.72
(Matthew Bender)
436–439. Reserved for Future Use