McGhee v National Coal Board is probably the most instructive case on the matter. It brought a 'material increase in risk' test to apply to the causation step of analysis. The case has been widely cited and has had international impact.

https://en.wikipedia.org/wiki/McGhee_v_National_Coal_Board

Your jurisdiction might deal with things differently, but this case has had international adoption, as the framework deals with scientific uncertainty fairly elegantly.