The defense asserts that a substantial post-sale alteration caused the harm and that the manufacturer is not responsible for a product no longer in its original condition. Foreseeable modifications do not defeat liability.
Guard and safety device removal is the recurring scenario.
Alternative Names:
Modification Defense (Products), Post-Sale Alteration
Why it Matters?
Foreseeability determines the outcome, and manufacturers of industrial equipment frequently lose because internal documents show they knew guards were removed in the field to increase throughput. Evidence that the manufacturer designed against modification, provided interlocks, or warned specifically about removal is what supports the defense. The employer that made the modification is typically immune under workers' compensation, which leaves the manufacturer bearing the full exposure.
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Related terms
Frequently asked questions
Why does the defense often fail?
Who typically made the modification?
