Final answer:
Ellie's Engineering might use defenses such as assumption of risk, contributory negligence, and the fellow-servant rule against Karen's lawsuit, arguing her awareness of dangers, failure to warn, and Josh's negligence.
Step-by-step explanation:
The common law defenses that Ellie's Engineering might use to defend themselves against a lawsuit filed by Karen would likely include the assumption of risk, contributory negligence, and perhaps the fellow-servant rule. The assumption of risk defense could claim that Karen was aware of the dangers posed by the explosive chemicals but chose to participate in the work without objecting or taking additional precautions.
Contributory negligence might be argued on the basis that Karen's failure to inform Bill and Josh of the chemical's dangerous nature contributed to the accident. Additionally, the fellow-servant rule may be invoked, suggesting that the company is not liable for injuries caused by the negligence of fellow employees, in this case, Josh's mishandling of the truck.