Workers Health & Safety Centre

Amendments to Ontario toxic substance regs now in force

Many recent changes to Ontario law governing exposure to chemical and biological agents are little more than housekeeping, but some alter how employers must protect workers.
Amendments to Regulation 833 (Control of Exposure to Biological or Chemical Agents) and Regulation 490 (Designated Substances) came into force on January 1, 2020. Changes to both add several new definitions relating to respirators and breathing apparatus along with short-term exposure limits (STEL).
Also new is a requirement in Regulation 833 for employers to consider substitution of a hazardous substance as a control measure in order to meet their obligation to protect workers. Fortunately, employers and other workplace parties can access a wealth of critical support to help find safer alternatives for informed substitution.
Furthermore, administrative edits to Regulation 490 clarify the duty of employers to take reasonable precautions to protect their own workers and “third party workers”, including contractors, who are exposed to the designated substance (section 14 & 15).

Additional examples of amendments include:
  • replacing separate Codes for Respiratory Equipment with a single Respiratory Protection Program incorporating parts of CSA Standards Z94.4-18 and Z180.1-13 (R2018) giving them force of law
  • replacing the nine separate Medical Surveillance Codes with a single Code for Medical Surveillance for Designated Substances
  • permitting the use of a range of acceptable standard methods for air sampling and analysis
  • requiring air sampling and analysis be done by a person who is qualified because of knowledge, training and experience in industrial hygiene practice, and
  • permitting the use of the “Quebec model” for calculating exposures to hazardous substances for irregular work shifts.

Guarded optimism and concern

Advocates are applauding some of the amendments including the employer duty to train workers in the use and care of respirators “prior to beginning work.” Many are guardedly optimistic employers will act on these new obligations, including giving serious consideration to substituting a hazardous agent with a safer alternative.  
Questions remain, however, whether or not government regulators will adequately enforce these new standards. For instance, the recently released 2019 Ontario Auditor General Report highlights this concern, citing the existing low level of Ministry of Labour enforcement and prosecution.
In addition, the introduction of the “Quebec model” for calculating exposures for non-standard work shifts is a concern for many. While this new tool works for many substances, it does not allow measurement adjustments for irritants. Without these adjustments, a worker can be exposed to an irritant at levels less than the legal limit, but still face a risk to health including the development of asthma and chronic obstructive pulmonary disorder (COPD).
Furthermore, despite concerns raised during public consultation about the amendments, Regulation 490 still does not apply at a project, to an employer who engages in construction or their workers at the project.

WHSC can help

The WHSC offers a number of training programs and resources to help workplace parties including supervisorsjoint health and safety committee members and representatives understand their significant obligations related to harmful chemical and biological agents. These programs offer essential insight into the tools and information needed to identify and control or eliminate exposures.
Employers also have significant obligations, including training, designed to ensure workers can identify hazardous substances at work, understand the risk to health, along with safety precautions. WHSC Mandatory WHMIS training is one such program.    
To learn more about obligations pertaining to toxic substances at work, including WHMIS training: 

Call:    1-888-869-7950 and ask to speak with a training services representative, or
Related resources:
Occupational disease site offers insights on exposure and prevention
Regulation an important driver of workplace chemical substitution, study finds
Lung disease in nurses linked to disinfectant use at work
WHMIS resources