DDT was first registered in 1946 and used in Canada to control insect pests in crops as well as in domestic and industrial applications. DDT was never manufactured in Canada. In response to environmental and safety concerns, most uses of DDT were phased out by the mid-1970s. Registration of all remaining uses of DDT was discontinued in 1985 with the understanding that existing stocks would be sold, used or disposed of by 31 December 1990. After this date, any sale or use of DDT in Canada represents a violation of the Pest Control Products Act.