9. Toxic Substances
A toxic substance is a biological, chemical or physical agent (or a combination of such agents) whose presence or use in the workplace may endanger the health or safety of a worker.
Throughout the Occupational Health and Safety Act and regulations, the terms "hazardous substances", "hazardous materials" or "hazardous agents" are all used to describe toxic substances. You can interpret any of these terms to mean "toxic substances".
The parts of the Act that deal with toxic substances have two purposes. One is to ensure that worker exposure to toxic substances is controlled. The other is to ensure that toxic substances in the workplace are clearly identified and that workers receive enough information about them to be able to handle them safely.
As well, it gives the general public access to information about toxic substances used by industries in their community. All of these requirements relating to toxic substances are described in this chapter.
The Control of Toxic Substances
There are three ways that worker exposure to toxic substances can be controlled under the Act.
- Designated Substance Regulations
The Act allows a toxic substance to be "designated", and its use in the workplace to be either prohibited or strictly controlled.
Designation is reserved for substances known to be particularly hazardous.
Eleven substances have been designated under the Act, including asbestos, lead, mercury and arsenic. Separate regulations have been passed for each one. In general, each regulation sets out the amount of the substance that workers can be exposed to in a given time period, and the ways to both control and measure the substance in the workplace.
More information on designated substances appears in a separate guide, Designated Substances in the Workplace: A General Guide to the Regulations, available from the Ministry of Labour and Publications Ontario.
- Regulation to Control Exposure to Biological or Chemical Agents
The Act permits atmospheric conditions in the workplace to be controlled. The Regulation respecting Control of Exposure to Biological or Chemical Agents, Regulation 833, sets limits in workplace air for approximately 600 toxic substances.
- "Section 33" Order
Section 33 of the Act permits a director to issue an order to an employer to either prohibit or restrict the presence, use or intended use of a toxic substance in the workplace [section 33(1)].
For example, the director may order that a toxic substance can be used only if the workers exposed to it wear specified protective equipment or receive exposure to it only for a specified period of time.
Section 33 orders can be issued to the self-employed.
What happens when a section 33 order is issued?
The employer must comply immediately with the order. The employer must also give a copy of the order to the health and safety committee or representative and, if there is one, the trade union.
The employer must also post a copy of the order in the workplace, where it is most likely to be seen by the workers who may be affected by the toxic substance [section 33(3)].
Can an employer appeal a section 33 order?
Yes. Within 14 days of the order being issued, an appeal in writing can be made to the minister. A worker or trade union can also appeal the director's order [section 33(4)].
The minister can appoint a person to hear the appeal [section 33(5)]. This person has the power to suspend the order until a decision on the appeal has been made [section 33(9)]. He or she can also confirm or change in any way the order of the director. His or her decision is final [section 33(7)].
Section 33 orders do not apply to designated substances [section 33(11)].
The Right to Know About Toxic Substances
The Act gives workers the right to know about toxic substances in the workplace. This right has always been part of the Act, but it was significantly expanded in 1988, when the Act was amended as part of the Canada-wide implementation of the Workplace Hazardous Materials Information System (WHMIS).
The sections of the Act that implement WHMIS use the term "hazardous materials" instead of toxic substances. Therefore, for the remainder of this chapter, which outlines the general duties of the employer under WHMIS, the term "hazardous materials" is used.
Detailed requirements are set out in a separate WHMIS regulation, Regulation for Workplace Hazardous Materials Information System, Regulation 860. More information about the WHMIS requirements in the Act and regulations appears in a separate guide, Workplace Hazardous Materials Information System (WHMIS): A Guide to the Legislation, available from the Ministry of Labour and Publications Ontario.
Employer's Responsibilities Concerning Hazardous Materials
An employer in charge of a workplace where hazardous materials are used has three main duties: to identify hazardous materials, to provide Material Safety Data Sheets (MSDSs) and to train workers.
Identifying Hazardous Materials
The employer must ensure that all hazardous materials in the workplace are identified in a prescribed way [section 37(1)(a)].
In most cases, a detailed label is required on a container of a hazardous material. In some cases, however, a less formal means of identification is permitted. The WHMIS Regulation sets out how and when hazardous materials must be identified.
For hazardous materials that the employer buys from a supplier, the label/identification must be provided by the supplier. The employer is required to notify the Ministry of Labour in writing if, after making reasonable efforts such as telephoning and/or writing the supplier, he or she is unable to obtain proper labels [section 37(4)].
No one in the workplace can remove or deface the identification of a hazardous material [section 37(2)].
Where the identification of a hazardous material is in writing (rather than represented by colour coding or symbols, for example), it must be in English and any other prescribed languages [section 37(1)(c)].
Providing Material Safety Data Sheets (MSDSs)
The employer has a general duty to either obtain or prepare unexpired MSDSs for hazardous materials in the workplace [section 37(1)(b)]. "Unexpired" means dated within the past three years [section 37(5)].
The information that an MSDS must include, along with some exemptions to this general duty, is defined by regulation.
For a hazardous material that the employer buys from a supplier, the MSDS must be provided by the supplier. If an employer is unable to obtain an MSDS from a supplier of a hazardous material, the employer is required to notify, in writing, a director of the Ministry of Labour [section 37(4)]. For a hazardous material that the employer produces on site for use in the workplace, the employer must prepare the MSDS.
The employer is required to make copies of MSDSs readily available to workers, to the joint committee or to the health and safety representative, if any [section 38(1)]. Wider distribution of MSDSs is discussed later in this chapter, in the section "Public Access to Material Safety Data Sheets".
The employer can make MSDSs available to workers on a computer terminal, provided the terminal is kept in working order and that appropriate computer training is given to exposed workers, to joint committee members or to the health and safety representative, if there is one. The employer must also provide workers with paper copies of MSDSs, on request [section 38(6)].
Training Workers
The employer has a general duty to train workers who are exposed or are likely to be exposed to a hazardous material on the job [section 42(1)]. Specific training requirements are set out in the WHMIS Regulation.
The employer must consult either the joint committee or a worker health and safety representative, if there is one, about the content and delivery of training programs [section 42(2)].
At least once a year, the employer, in consultation with the joint committee or a health and safety representative, must review the worker training program and determine the workers' familiarity with the information [section 42(3)]. This review should take place more often than once a year if the employer, on the advice of the committee or representative, thinks it necessary [section 42(4)(a)]. A more frequent review is also required if there is a change at the workplace that may affect the health or safety of a worker [section 42(4)(b)].
The requirement for a review of the training program is not an automatic requirement to retrain workers. The review is meant to identify whether updating of the training program and retraining of workers are necessary.
Assessment of Biological and Chemical Agents
The Act places a general duty on the employer to determine whether a biological or chemical agent produced for use in the workplace is a hazardous material [section 39]. Procedures are set out in the WHMIS Regulation.
In the Act and the WHMIS Regulation, the process of determining whether a material produced in the workplace is hazardous is called an "assessment". The assessment should be in writing and a copy made available to workers as well as given to the joint committee or a worker health and safety representative, if there is one [section 39(2)].
Employers subject to any of Ontario's designated substance regulations may be familiar with the term "assessment". The term has a different meaning in the WHMIS Regulation than in the designated substance regulations. Under WHMIS, an assessment refers only to deciding whether a product produced in the workplace is a hazardous material. In the designated substance regulations, an assessment refers to evaluating worker exposure to the designated substance.
Public Access to Material Safety Data Sheets (MSDSs)
The Act provides for the distribution of MSDSs outside the workplace. Specifically, the following can request copies of MSDSs from the employer:
- the medical officer of health
- the local fire department
- the Ministry of Labour.
It is through the medical officer of health that the public has access to MSDSs. Any member of the public has the right to go to his or her local medical officer of health and ask to see a copy of any or all MSDSs for a workplace within the public health unit served by the officer. If the medical officer of health does not have the pertinent MSDSs available, he or she must obtain them from the employer [sections 38(2) and (3)].
The medical officer of health cannot disclose the name of any person asking to see an MSDS [section 38(4)].
Confidential Business Information
The Act provides protection for confidential business information [section 40]. The employer can file a claim with the "claims board" to be exempted from disclosing information that is normally required on a label or MSDS if the employer believes it to be confidential business information.
The "claims board" referred to in the Act is the Hazardous Materials Information Review Commission, which is an agency of the federal government.
Most of the requirements covering confidential business information are set out in other acts and regulations–the federal Hazardous Materials Information Review Act and regulations, the federal Controlled Products Regulation, and the Ontario WHMIS Regulation. For a full understanding of how such information is treated under occupational health and safety law, one must refer to these acts and regulations. A brief explanation of the requirements in these laws appears in Workplace Hazardous Materials Information System (WHMIS): A Guide to the Legislation, which is available from the Ministry of Labour and Publications Ontario.
Detailed information on the Hazardous Materials Information Review Act is also available from:
The Hazardous Materials Information Review Commission427 Laurier Avenue West, 7th Floor
Ottawa, Ontario K1A 1M3
Telephone: 613-993-4331
Fax: 613-993-4686
Website: www.hmirc-ccrmd.gc.ca
Hazardous Physical Agents
The requirements for labels, material safety data sheets and training apply to chemical and biological agents only, not to physical agents. Physical agents are things like noise, heat, cold, vibration and radiation.
The Act allows for regulations to be passed that would require both the suppliers of equipment that produces a hazardous physical agent and the employers who use such equipment to provide specific information about the agent [section 41]. At present, no such regulation exists. There is, however, a general duty on the employer to acquaint a worker and a supervisor with any hazard related to a physical agent in the workplace. [ 1 ]
[ 1 ] The provisions of the Act covering identification of hazardous materials, MSDSs, assessments, public access to MSDSs, inventories, floor plans, trade secrets and hazardous physical agents also apply to self-employed persons.
