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Part IV: Toxic Substances

  • Revised: March 20, 2015
  • Content last reviewed: March 2015
  • Also available in Spanish [PDF, 729 Kb / 82 pages ]

Disclaimer: This resource has been prepared to help the workplace parties understand some of their obligations under the Occupational Health and Safety Act (OHSA) and regulations. It is not legal advice. It is not intended to replace the OHSA or the regulations. For further information please see full disclaimer.

In this section, the term “toxic substance” will be used to refer to 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.

The parts of the Occupational Health and Safety Act (OHSA) 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, the Act gives the general public access to information about toxic substances used by regulated employers in their workplaces.

Additional regulatory requirements relating to toxic substances are also described in the following section.

The Control of Toxic Substances

There are several ways that worker exposure to toxic substances can be controlled under the Act.

Regulations for Designated Substances

The Act enables the Lieutenant Governor in Council (LGIC) to prescribe a toxic substance as a “designated substance”, and to prohibit, regulate, restrict, limit or control its use, handling and removal in regulated workplaces.

Designation is typically reserved for substances known to be particularly hazardous to the health and safety of workers.

Eleven substances have been prescribed as designated substances in one regulation under the Act (Designated Substances O. Reg. 490/09), including asbestos, lead, mercury and arsenic. The regulation prescribes the maximum amount of the designated substances that workers can be exposed to in a given time period and the ways to both control and assess the substances in the workplace. There is also a specific regulation relating to the designated substance asbestos on construction projects, buildings and repair operations (O. Reg. 278/05 - Designated Substance - Asbestos on Construction Projects and in Buildings and Repair Operations) as well as a Guide to the Regulation.

Regulation for Control of Exposure to Biological or Chemical Agents

The Act enables the LGIC to regulate the atmospheric conditions to which a worker may be exposed in the workplace. The Regulation respecting Control of Exposure to Biological or Chemical Agents, Regulation 833, sets occupational exposure limits (OELs) for approximately 725 biological and chemical agents.

“Section 33” Order

Where the Director is of the opinion that a toxic substance is likely to endanger the health and safety of a worker, section 33 of the Act allows a Director of the Ministry of Labour to issue an order to an employer which would prohibit or restrict the presence, use or intended use of a toxic substance in the workplace or specify that its use/intended use be subject to specific conditions (i.e. conditions regarding administrative control, work practices, engineering controls and time limits for compliance [subsection 33(1)]. Section 33 orders do not apply to designated substances [subsection 33(11)].

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 are exposed to it only for a specified period of time.

What happens when a section 33 order is issued?

Unless the employer has within 14 days of its issuance by the Director provided written notice of his or her intention to appeal the order to the Minister, the employer must comply immediately with the order. The employer must also give a copy of the order to the joint health and safety committee or health and safety representative and the trade union (if applicable).

The employer must 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 use, presence, or intended use of the toxic substance [subsection 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 of Labour. A worker or trade union can also appeal the Director's order [subsection 33(4)].

The Minister may appoint a person to determine the appeal [subsection 33(5)]. This person has the power to suspend the operation of the order until a decision on the appeal has been made [subsection 33(9)]. He or she can also affirm or rescind the order of the Director or make a new order. His or her decision is final – i.e., not subject to any further appeal [subsection 33(7)].

The Act specifies the relevant factors to be considered by the Director when making an order and by the Minister or person appointed by the Minister when determining an appeal [subsection 33(8)].

The Right to Know About Hazardous Materials

The Act gives workers the right to know about hazardous materials 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).

Hazardous materials are defined as biological or chemical agents, which are named or described in regulation as hazardous materials. Detailed requirements regarding hazardous materials are set out in Regulation 860, Workplace Hazardous Materials Information System (WHMIS). More information about the WHMIS requirements in the Act and regulations appears in a separate Ministry of Labour guide, Workplace Hazardous Materials Information System (WHMIS): A Guide to the Legislation. It is also available from ServiceOntario Publications.

Note: Canada intends to implement a new international system for classifying and labelling chemicals called the Globally Harmonized System (GHS). Once implemented, it will impact the current MSDS and labelling requirements under WHMIS. GHS would be implemented within the context of the WHMIS legislation in Canada.

Employer's Responsibilities Concerning Hazardous Materials

An employer has various duties relating to hazardous materials, including the duty:

  • to identify hazardous materials in the prescribed manner
  • to obtain or prepare (as may be prescribed) Material Safety Data Sheets (MSDSs), and
  • to provide information and prescribed instruction and training to workers who are exposed or likely to be exposed to hazardous materials and to ensure that the workers participate in such training

Moreover, employers are required to ensure that hazardous materials are not handled, used or stored at a workplace unless the prescribed requirements relating to identification, MSDSs and worker instruction and training are met.

Where an employer is unable to obtain a label or MSDS after making reasonable efforts to do so, he or she is required to notify a Director.

Identifying Hazardous Materials

The employer must ensure that all hazardous materials in the workplace are identified in a prescribed manner and obtain or prepare, as prescribed, an unexpired material safety data sheet for all hazardous materials present in the workplace [clause 37(1)(a)].

The employer shall ensure that the MSDS is in English and any other prescribed languages [clause 37(1)(c)].

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 (Regulation 860) sets out how and when hazardous materials must be identified.

The employer is required to notify the Ministry of Labour in writing if, after making reasonable efforts he or she is unable to obtain proper labels or material safety data sheets [subsection 37(4)].

No one in the workplace can remove or deface the identification of a hazardous material or a data sheet [subsection 37(2)].

An employer must make certain that a hazardous material is not used, handled or stored at a workplace unless all of the prescribed requirements regarding identification, MSDSs and worker instruction and training have been met [subsection 37(3)].

Providing Material Safety Data Sheets (MSDSs)

The employer has a duty to either obtain or prepare unexpired MSDSs for hazardous materials in the workplace [clause 37(1)(b)]. MSDSs expire three years after the date of their publication [subsection 37(5)].

The content of MSDSs is prescribed by regulation. The WHMIS Regulation prescribes the content of MSDSs for "controlled products". The Regulation designates all "controlled products" as hazardous materials. Therefore, this section of the guide will interchangeably refer to controlled products and hazardous materials.

An employer who obtains hazardous materials from a supplier is required to obtain an unexpired MSDS for the material [subsection 17(1) of the WHMIS regulation].

The employer may store hazardous material obtained from a supplier without a label, MSDS and a program of worker education while the employer is actively seeking the label and MSDS [subsection 5(1) of the WHMIS Regulation]. The employer may also store employer-produced hazardous material without a label or MSDS or without conducting a program of worker education while the employer is actively seeking information to produce the label and the MSDS.

The employer is required to prepare material safety data sheets for hazardous materials that are produced in the workplace, rather than purchased from a supplier [subsection 18(1) of the WHMIS Regulation]. The employer is required to disclose the same information on the material safety data sheet that the supplier is required to disclose on the supplier material safety data sheet [subsection 18(3) of the WHMIS Regulation].

Upon request of the parties noted below, the employer is required to disclose the source of any toxicological data used to prepare the MSDS. The parties that can request the employer to disclose the source of toxicological data include an inspector, a worker, a member of the joint health and safety committee, a health and safety representative, or a worker representative [section 25 of the WHMIS Regulation]. The employer can withhold the source of toxicological data if such information is confidential business information (e.g. a valid trade secret or proprietary).

The employer is required to update the workplace MSDS every three years, unless new hazard information becomes available, in which case the workplace material safety data sheet must be updated within 90 days of the new information becoming available [subsection 18(4) of the WHMIS Regulation].

The employer is not required to prepare a workplace MSDS for fugitive emissions produced in the workplace (e.g., gases or vapours from pressurized equipment that may result from leaks and various other unintended or irregular releases of gases, mostly from industrial activities) or for a hazardous material that exists only as an intermediate, and is undergoing further reaction within a process or reaction vessel [subsection 1(2) of the WHMIS Regulation].

The employer is required to make copies of MSDSs readily available to workers, to the joint health and safety committee or to the health and safety representative, if any, the relevant medical officer of health if requested or prescribed, the local fire department if requested or prescribed and to a Director of the Ministry of Labour if requested or prescribed [subsection 38(1) of the Act]. Wider distribution of material safety data sheets is discussed later in this chapter, in the section Public Access to Material Safety Data Sheets.

The employer is permitted to make material safety data sheets available to workers by means of a computer terminal, if the employer,

  1. takes all reasonable steps to keep the computer terminal in working order
  2. provides a paper copy of the MSDS if requested by a worker, and
  3. provides training on how to access computer-stored data sheets, to all workers working with or in proximity to controlled products, and to members of the joint health and safety committee or a health and safety representative [subsection 38 (5) of the Act].

Training Workers

The employer has a specific duty to provide prescribed information and instruction to workers who are exposed or likely to be exposed to a hazardous material on the job [subsection 42(1) of the Act]. Employers are further required to ensure that workers participate in any prescribed instruction/training. This is in addition to the general employer duty to provide information, instruction and supervision to workers to protect their health and safety.

In addition, the employer is obligated to consult the joint health and safety committee if there is one, or a worker health and safety representative, about the content, implementation and delivery of the instruction and training [subsection 42(2) of the Act].

The employer must inform the worker who works in close proximity to a hazardous material obtained from a supplier about all hazard information received from the supplier about the material and all further hazard information about which the employer is aware or ought to be aware concerning the storage, use and handling of the material In general, this means the information provided on supplier labels and material safety data sheets, but it can also include other information such as letters from the supplier in response to inquiries from the employer.

If the controlled product is produced in the workplace, the employer must inform the workers about all hazard information of which the employer is aware, or ought to be aware regarding its storage, use and handling [subsection 6(2) of the WHMIS Regulation].

Information about which the employer ought to be aware includes:

  • publications and computerized information available from the Canadian Centre for Occupational Health and Safety
  • publications available from industry or trade associations of which the employer is a member and from labour organization(s) representing workers at the workplace, and
  • publications from the Ontario Ministry of Labour.

The worker education program must cover the following six areas [subsection 7(1) of the WHMIS Regulation]:

  1. labels–the information required, the purpose of the information and the significance of the information
  2. modes of identification when used at the workplace instead of labels
  3. MSDSs–the information required, the purpose of the information and the significance of the information
  4. procedures for the safe use, storage, handling and disposal of a controlled product, including a controlled product in a piping system or vessel
  5. procedures to be followed where fugitive emissions are present, and,
  6. procedures to be followed in case of an emergency involving a controlled product.

The employer must ensure that the program of worker education is developed and implemented for the employer’s workplace and is related to any other training, instruction and prevention programs at the workplace.

An employer shall ensure, so far as is reasonably practicable, that the program of worker instruction required by subsection (1) results in the workers being able to use the information to protect their health and safety.

For more information on worker education in respect of WHMIS, please refer to the WHMIS guide.

New Biological and Chemical Agents

The Act requires that unless for the purposes of research and development, no new biological and/or chemical agents shall be manufactured, distributed or supplied for commercial or industrial use in a workplace, unless:

  • a notice of intention to manufacture, distribute or supply such an agent is submitted to a Director of the Ministry of Labour, and
  • the notice includes the ingredients of the new agent including their common or generic names and their composition and properties [subsection 34 (1)].

Assessment for Hazardous Materials

The OHSA requires that, in prescribed circumstances, an employer assess all biological and chemical agents in the workplace for use therein in order to determine if they are hazardous materials. This assessment must be in writing and must be made available in the workplace to allow examination by workers and provided to the health and safety representative, joint health and safety committee or worker selected by the workers to represent them (as applicable).

Public Access to Material Safety Data Sheets (MSDSs)

The OHSA provides for the distribution of MSDSs outside the workplace. Specifically, upon request or where prescribed, the employer must provide the MSDS to the following:

  • 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 area served by the public health unit. If the medical officer of health does not have the pertinent MSDSs available, he or she must obtain them from the employer [subsections 38(2) and (3)].

The medical officer of health is prohibited from disclosing the name of any person asking to see an MSDS [subsection 38(4)].

Confidential Business Information

The Act provides protection for types of confidential business information that are prescribed in Regulation [section 40]. The employer can file a claim with the Hazardous Materials Information Review Commission to be exempted from disclosing information that is normally required on a label or MSDS or the name of a toxicological study that was used to prepare an MSDS on the basis that it is confidential business information.

The Hazardous Materials Information Review Commission, is an agency of the federal government.

For more details on this issue, please refer to the Ministry of Labour’s Workplace Hazardous Materials Information System (WHMIS): A Guide to the Legislation. It is also available from ServiceOntario Publications.

Detailed information on the Hazardous Materials Information Review Act is also available from:

The Hazardous Materials Information Review Commission
427 Laurier Avenue West, 7th Floor
Ottawa, Ontario K1A 1M3
Telephone: (613) 993 4331
Fax: (613) 993-4686
Website

Hazardous Physical Agents

The statutory definition of hazardous materials does not include physical agents. Physical agents include noise, heat, cold, vibration and radiation. In specific factual circumstances, where no specific requirement addresses the use of potentially hazardous physical agents in the workplace, they may be regulated by requiring employers to take every reasonable precaution for the protection of workers in the circumstances.

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