The vast universe of chemicals in the Canadian environment is presently understood only poorly by science. For many thousands of chemicals, important data regarding chronic toxicity are lacking. As a result, the requirement that the plaintiff in a negligence action prove causation of illness on a but-for standard has frequently been unattainable. In Resurfice Corp. v. Hanke, the Supreme Court of Canada articulated an important exception to the but-for test. In circumstances where but-for causation is unprovable due to limits in scientific knowledge, proof that a defendant materially contributed to the plaintiff\u27s risk of incurring the type of injury that was ultimately suffered will satisfy the causation element. This reform is an important first step in the evolution of a tort regime that is capable of doing justice in the chemical era
