Product Liability actions arent always strict liability... in what instances can a product liability action be one in negligence rather than strict liability?
as an aside, when you make a claim for products liability you'd make a claim for SL and in the alternative for N.
Assuming we're in a state that has SL for PL then most every PL action is a SL case.
however, proving SL can often be like proving N. particularly with a design defect claim. using the 'hand' approach with a cost/benefit analysis we ask "did the cost of keeping this design outweigh the benefits of keeping this design?" this involves many factors of course, but if in the end it seems the design should have been altered then it is deemed a defective design. if it can be shown that the design is the cause of the accident then the P has a claim that we call SL but looks almost identical to a N claim.
there are also other aspects of PL that, while called SL, look somewhat similar to N claims (warnings, consumer expectations test for design defects).