The hurdle of proving causation on product liability claims could be lowered following a test cases, warned insurance law firm Reynolds Porter Chamberlain (RPC).

The first case forced all the employers an individual had worked for to share liability for the mesothelioma he had contracted from exposure to a single strand of asbestos.

RPC health practice partner Dorothy Flower said: "Previously, a claimant would have had to identify which of his employers was liable for his injury. This case makes it possible to make a claim against all the previous employers, who then have to share the liability.

"In the future it might well be that all manufacturers of a defective product will be obliged to share liability for any damage or injury that it causes, rather than the claimant having to prove whose product caused the injury.

"This has already happened in the US, where the award is split according to each manufacturer's market share of that particular product."