Product liability for design defects?

What the Law Says

Japan’s Product Liability Act (PLA) establishes strict liability for manufacturers whose defective products—including those with unsafe designs—cause harm to life, body, or property.

Under the PLA, a 'defect' includes flaws in design, manufacturing, or instructions/warnings. A design defect exists when the product’s design itself poses an unreasonable risk of harm, even if manufactured exactly as intended.

The law does not require proof of negligence — plaintiffs need only show that the product had a defect, that the defect existed when it left the manufacturer’s control, and that the defect caused the damage.

The burden shifts to the manufacturer to prove one of three defenses: (1) the defect could not have been discovered given scientific/technical knowledge at the time of delivery; (2) the defect arose after delivery; or (3) the state of scientific knowledge at the time made the defect undiscoverable.

Statutory Text

A person who has manufactured, processed or imported a product (hereinafter referred to as 'manufacturer') shall be liable to compensate for any damage caused by a defect in the product.

— Product Liability Act, s. 3 — Liability for Damage Caused by Defects

Statutory Text

For the purposes of this Act, 'defect' means that the product fails to provide the safety which one may legitimately expect, taking into account all circumstances such as the characteristics of the product, the manner in which it is used or foreseeable to be used, its presentation, and the time when it was supplied.

— Product Liability Act, s. 2(1) — Definition of 'Defect'

What to Do

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