CACI No. 1208. Component Parts Rule
Judicial Council of California Civil Jury Instructions (2025 edition)
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1208.Component Parts Rule
[Name of defendant] [manufactured/distributed/supplied] [a/an]
[component part], which was then integrated into [a/an] [end product].
[Name of defendant] may be liable for harm caused by a defective [end
product] if [name of plaintiff] proves that (1) [name of defendant]
substantially participated in the integration of its [component part] into
the design of the [end product] and (2) as a result of the integration of
the [component part] into the [end product], the [end product] was
defective under the instruction(s) you have been given on [manufacturing
defect/design defect/failure to warn].
New November 2018
Directions for Use
Give this instruction if the component parts rule is at issue. This rule generally
relieves a component parts manufacturer, distributor, or supplier of liability for
injuries caused by a defect in the product into which the component was integrated.
However, there are two exceptions to the rule so that a component-parts defendant
may nevertheless be found liable. First, the component itself may have been
defective; or second, (a) the defendant may have substantially participated in the
integration of the component into the design of the end product, (b) the integration
of the component caused the end product to be defective, and (c) the defect in the
product causes the harm. (Ramos v. Brenntag Specialties, Inc. (2016) 63 Cal.4th
500, 508 [203 Cal.Rptr.3d 273, 372 P.3d 200].) While the component parts rule is
labelled a defense (see Webb v. Special Electric Co., Inc. (2016) 63 Cal.4th 167, 183
[202 Cal.Rptr.3d 460, 370 P.3d 1022]; see also Romine v. Johnson Controls, Inc.
(2014) 224 Cal.App.4th 990, 1006 fn. 6 [169 Cal.Rptr.3d 208]), the plaintiff has the
burden of avoiding the defense by proving one of the exceptions.
This instruction is for use under the second exception. To prove that the end product
was defective or lacked a required warning, the plaintiff must prove a manufacturing
or design defect, or a failure to warn, as with any other strict product liability claim,
using CACI No. 1201, Strict Liability - Manufacturing Defect - Essential Factual
Elements, CACI No. 1203, Strict Liability - Design Defect - Consumer Expectation
Test - Essential Factual Elements, or CACI No. 1204, Strict Liability - Design
Defect - Risk-Benefit Test - Essential Factual Elements (or both),or CACI No. 1205,
Strict Liability - Failure to Warn - Essential Factual Elements. The plaintiff has the
same burden if the claim is that the component itself was defective or lacked a
required warning.
The component parts rule does not apply if the injury is caused by the component
when it is being used as intended before integration into another product. (See
Ramos, supra, 63 Cal.4th at p. 504.)
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Sources and Authority
• “Another defense protects manufacturers and sellers of component parts from
liability to users of finished products incorporating their components. Under the
component parts doctrine, the supplier of a product component is not liable for
injuries caused by the finished product unless (1) the component itself was
defective and caused injury or (2) the supplier participated in integrating the
component into a product, the integration caused the product to be defective, and
that defect caused injury.” (Webb, supra, 63 Cal.4th at p. 183.)
• “In Webb [supra], we explained that the component parts doctrine . . . and as
accurately reflected in section 5 of the Restatement Third of Torts, Products
Liability - applies (1) when a supplier provides a component or raw material that
is not itself defective (by virtue of a manufacturing, design, or warning defect),
(2) the component or raw material is changed or transformed when incorporated
through the manufacturing process into a different finished or end product, and
(3) an end user of the finished product is allegedly injured by a defect in the
finished product.” (Ramos, supra, 63 Cal.4th at pp. 507-508, internal citations
omitted.)
• “[T]he component parts doctrine provides protection to the supplier of the
component or raw material, subjecting that entity to liability for harm caused by
a product into which the component has been integrated only if the supplier
“(b)(1) . . . substantially participates in the integration of the component into the
design of the product; and [¶] (2) the integration of the component causes the
product to be defective . . . ; and [¶] (3) the defect in the product causes the
harm.” (Ramos, supra, 63 Cal.4th at p. 508.)
• “ ‘Component parts are products, whether sold or distributed separately or
assembled with other component parts.’ ‘Product components include raw
materials, bulk products, and other constituent products sold for integration into
other products.’ Component manufacturers and suppliers, as sellers of ‘products,’
are subject to products liability. ‘Like manufacturers, suppliers, and retailers of
complete products, component manufacturers and suppliers are “an integral part
of the overall producing and marketing enterprise,” and may in a particular case
“be the only member of that enterprise reasonably available to the injured
plaintiff,” and may be in the best position to ensure product safety.’ ” (Johnson v.
United States Steel Corp. (2015) 240 Cal.App.4th 22, 33 [192 Cal.Rptr.3d 158],
internal citations omitted.)
• “[T]he duty of a component manufacturer or supplier to warn about the hazards
of its products is not unlimited. . . . ‘Making suppliers of inherently safe raw
materials and component parts pay for the mistakes of the finished product
manufacturer would not only be unfair, but it also would impose and [sic]
intolerable burden on the business world . . . . Suppliers of versatile materials
like chains, valves, sand gravel, etc., cannot be expected to become experts in
the infinite number of finished products that might conceivably incorporate their
multi-use raw materials or components.’ Thus, cases have subjected claims made
against component suppliers to two related doctrines, the ‘raw material supplier
CACI No. 1208 PRODUCTS LIABILITY
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defense’ and ‘the bulk sales/sophisticated purchaser rule.’ Although the doctrines
are distinct, their application oftentimes overlaps and together they present
factors which should be carefully considered in evaluating the liability of
component suppliers. Those factors include whether the raw materials or
components are inherently dangerous, whether the materials are significantly
altered before integration into an end product, whether the supplier was involved
in designing the end-product and whether the manufacturer of the end product
was in a position to discover and disclose hazards.” (Artiglio, supra, 61
Cal.App.4th at p. 837.)
• “[T]he protection afforded to defendants by the component parts doctrine does
not apply when the product supplied has not been incorporated into a different
finished or end product but instead, as here, itself allegedly causes injury when
used in the manner intended by the product supplier.” (Ramos, supra, 63 Cal.4th
at p. 504.)
• “The Restatement further explains ‘Product components include raw
materials. . . . Thus, when raw materials are contaminated or otherwise defective
within the meaning of § 2(a), the seller of the raw material is subject to liability
for harm caused by such defects.’ California courts have generally adopted the
component parts doctrine as it is articulated in the Restatement.” (Brady v.
Calsol, Inc. (2015) 241 Cal.App.4th 1212, 1219 [194 Cal.Rptr.3d 243], internal
citation omitted.)
• “The California Supreme Court has not determined whether the component parts
defense is limited to fungible products.” (Romine, supra, 224 Cal.App.4th at p.
1006, fn. 6.)
Secondary Sources
6 Witkin, Summary of California Law (11th ed. 2017) Torts, §§ 1617, 1666
1209-1219. Reserved for Future Use
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