Workplace Hazardous Materials Information System (WHMIS)

WHMIS is a combination of federal and provincial legislation concerning workplace safety procedures. To implement WHMIS in Ontario, the legislature amended the Occupational Health and Safety Act (OHSA) by means of Bill 79. The amended OHSA has three features not included in

WHMIS. These new features are additions to the right-to-know system.

1) Hazardous Physical Agents:

The amended Act also covers hazardous physical agents such as noise, vibration and radiation, so that the supplier and employer which emit hazardous physical agents

2) Workplace Inventories:

The employer is required to develop and maintain an inventory of hazardous material and hazardous physical agents in the workplace.

3) Public Right To Know:

WHMIS covers only the workers' right to know about workplace hazards. The Ontario amendment extends this right to the public.

The purpose of WHMIS is threefold:

1) to provide information about hazardous materials, and;

2) to identify hazards in the workplace, and;

3) to ensure consistency of information about hazardous materials in all Canadian workplaces.

The WHMIS information delivery system is comprised of:

A. labels,

B. Material Safety Data Sheets (MSDS), and

C. worker education.


The label is the primary and basic form of WHMIS hazard warning to employers and workers. As well as displaying fundamental information about the risks concerning the material inside the container, the label must also direct the reader to the MSDS. The workplace label must contain the

following information:

1) product identifier,

2) safe handling instructions (precautionary measures)

3) MSDS statement.

Material Safety Data Sheets

The MSDS provide information on the hazardous ingredients, properties and potential hazards of a product. Unexpired MSDS' must be available in the workplace for all hazardous materials used. Nine categories of information are required on a MSDS. The categories are as follows:

1) hazardous ingredients,

2) preparation information,

3) product information,

4) physical data,

5) fire or explosion hazard,

6) reactivity data,

7) toxicological properties,

8) preventive measures,

9) first aid measures.

Worker Education Program

Employer Responsibilities

The employer has a duty to train workers so that they understand the information on the labels and Material Safety Data Sheets of the hazardous materials/controlled products to which they may be exposed. The employer must also ensure that a worker comprehends the necessary procedures for

the safe handling, storage and disposal of a material and possesses the required knowledge of emergency procedures.

WHMIS Worker Education Requirements

All employees who work with or in proximity to a controlled product must be informed about the hazard information received from the supplier. The employees must be instructed concerning:

It is illegal to violate any of the above requirements.