In October 1988, the Workplace Hazardous Materials Information System (WHMIS) became law in Canada and was applied to school classrooms and laboratories. Educators expressed concerns that difficulties in implementation would negatively affect student laboratory activity. In 1994, a survey of 219 randomly selected Manitoba junior and senior high school science teachers (128 rural and 91 urban) examined issues related to implementation and effects of WHMIS regulations. Results show that while WHMIS knowledge and implementation were generally low, rural teachers scored significantly lower than urban teachers. Both rural and urban teachers scored higher on items that were part of their safety routines before WHMIS regulations. Urban and rural teachers reported few accidents, and accidents were not a result of noncompliance with WHMIS. WHMIS inspections were related positively to higher knowledge and implementation categories. Higher WHMIS knowledge and implementation scores were associated with the following teacher characteristics: more experience in subjects and grade levels currently assigned, teaching grades 11-12, more university science courses, more science methods and curriculum courses, and access to a laboratory assistant. Compared to rural teachers, urban teachers had a significant advantage in most of these areas. High percentages of both rural and urban teachers met or exceeded the number of science activities recommended by grade 11-12 provincial guides. The effect of WHMIS implementation on student laboratory activity was inconclusive. Contains 33 references. (Author/SV)