Traditionally in Canada, there are three health and safety rights: the right to participate (joint workplace health and safety committees); the right to refuse unsafe and unhealthy work; and the right to know about workplace hazards. By the end of the 1970s, the right to know had been established in law across Canada, but it was not enough to cover workplace chemical hazards in particular. The Workplace Hazardous Materials Information System (WHMIS) was a project set up by the Canadian federal government in 1982 to address the issue. This article tells the story of how labor got the progressive WHMIS agreement(1985) and how the agreement has been implemented in the following years.