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What is WHMIS?

WHMIS stands for Workplace Hazardous Materials Information System. It is a nationwide system to provide information on hazardous materials used in the workplace. WHMIS affects workers, employers, suppliers, and regulators. Nova Scotia’s WHMIS Regulations place duties at any workplace covered by the Occupational Health and Safety Act where hazardous materials are used, stored, or handled.

WHMIS Classifications

WHMIS uses classifications, or classes, to group chemicals with similar properties or hazards. The Controlled Products Regulations specifies the criteria used to place materials within each classification. There are six (6) classes although several classes have divisions or subdivisions.

Class A: Compressed Gases

Cylinders store compressed gases under pressure. Because gas leaking from a cylinder, a value or a regulator can cause injury or damage, WHMIS treats all compressed gases as controlled products. Gases which are also flammable, toxic or have other hazardous properties will also be found in other classes.

Typical compressed gases are oxygen which is used in health care and welding, and ammonia which is used in some large scale refrigeration systems.

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2232 points

Yasin Dahi

Developer @Learnful

Waterloo, ON


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WHMIS Lesson by Yasin Dahi is licensed under a Creative Commons Attribution-NonCommercial License (CC BY-NC), except where otherwise noted.