Disclaimer

This resource does not replace the Occupational Health and Safety Act (OHSA) and its regulations and should not be used as or considered legal advice. Health and safety inspectors apply and enforce these laws based on the facts they find in the workplace.

We have included links to other websites, but this does not mean that we endorse their information as compliant with the OHSA or the regulations.

This page focuses on occupational illness under the OHSA. While this page includes references to the Workplace Safety and Insurance Act, 1997 (WSIA) and to occupational disease where they may relate to occupational illness under the OHSA, this page is not intended to provide information about rights and duties under the WSIA.

Learn more about occupational disease under the WSIA.

Overview

Occupational illness is defined under the OHSA to mean a condition that occurs due to exposure in a workplace to a biological, chemical or physical agent to the extent that the normal physiological mechanisms are affected, and the health of the worker is impaired and includes an occupational disease for which a worker is entitled to benefits under the WSIA.

Things that cause occupational illness

Some examples of things that cause occupational illness include:

  • biological:
    • mould
    • virus
    • bacteria
    • plant product
    • animal product
  • chemical:
    • silica
    • lead
    • diesel exhaust
    • isocyanates
    • carbon monoxide
  • physical:
    • vibration
    • noise
    • heat
    • radiation

There are many other agents beyond this list that can cause occupational illnesses. These are distinguished from the hazards that lead to other types of work-related health problems, such as:

  • musculoskeletal disorder hazards
  • safety-related hazards

Occupational disease is a term defined under the WSIA. While the terms “occupational illness” (as defined under the OHSA) and “occupational disease” (as defined under the WSIA) refer to similar concepts, these terms are not interchangeable.

Occupational illnesses can look the same as illnesses or diseases not connected to the workplace. For example, somebody with work-related asthma might have the same signs and symptoms as any other person with asthma.

Onset of effects

When you are exposed to something that could affect your health at work, sometimes the effects are sudden and obvious, such as after certain chemical exposures like industrial solvents or carbon monoxide.

Other times, the effects might take months or years to develop. Longer onset is common, for example, for conditions, such as:

  • silicosis
  • dermatitis
  • noise-induced hearing loss
  • hand-arm vibration syndrome

Learn about what you need to know as a worker, employer or health care professional.

How to prevent exposure

With the right controls in place and by having a strong internal responsibility system, employers can reduce the risk of occupational illnesses by minimizing or eliminating exposures to workplace hazards.

Regular workplace assessments

Regular workplace assessments are important to occupational health and safety. While employers are ultimately responsible for protecting workers, joint health and safety committees or health and safety representatives can also be involved in identifying workplace hazards such as:

  • products being used, such as chemicals and hazardous substances
  • processes that happen, such as working with particular tools or tasks that may expose a worker to a biological, chemical or physical agent

After a committee or representative identifies a hazard, they can make recommendations to the employer on how to control a worker's exposures to it.

Controlling exposure

When certain substances or processes are determined to be a risk to a worker’s health, the risk can be controlled in many ways.

The hierarchy of controls is a framework that an employer can use to rank and implement control measures to protect workers from exposure. Control measures fall under the following categories, ordered from most effective and protective to the least effective and protective.

  1. Elimination or substitution: For example remove or replace substances or processes that could be harmful. It may be helpful to involve purchasers and work process designers to achieve this.
  2. Engineering: For example design the work area to reduce exposure to hazards. Engineering controls include ventilation and barriers.
  3. Administrative controls: For example provide training and supervision on how to avoid exposure to hazards and limit exposures through work scheduling and breaks.
  4. Personal protective equipment: For example, ensure workers wear protective gear, such as respirators to prevent them from breathing in hazardous substances, or appropriate gloves or garments to protect the hands and skin.

Occupational Health and Safety Act and regulations

There are requirements throughout the OHSA and its regulations that may relate to protection from workplace exposures that may cause occupational illness. These include, but are not limited to, certain OHSA regulations which focus on protection from various types of workplace exposures that may cause occupational illness. Some key examples include:

Employers are required to acquaint a worker and a person in authority over a worker with any hazard in the work and train that worker in the handling, storage, use, disposal and transport of any article, device, equipment or a biological, chemical or physical agent (s. 25 (2)(d) of the OHSA).

Read the rights and duties of workplace parties described in the OHSA and the regulation on the Workplace Hazardous Materials Information System (WHMIS).

Even where a hazardous substance is not explicitly addressed in the OHSA or its regulations (for example, exposure to vibration from the use of vibrating tools), general duties under the OHSA continue to apply. For example, the OHSA requires employers to take every precaution reasonable in the circumstances for the protection of a worker. This may include taking steps to protect workers from hazardous exposures.

Partner resources

The Ministry of Labour, Immigration, Training and Skills Development funds 6 health and safety associations that provide training, consulting and clinical services for workers and employers related to workplace hazards and occupational illness:

Information for workers

OHSA rights and duties

The OHSA establishes legal requirements that provide a foundation for the internal responsibility system (IRS). The IRS is a system within an organization in which everyone has a responsibility for workplace health and safety that is appropriate to one’s role and function within the organization.

Learn more about the Internal Responsibility System (IRS).

As a worker, you should know and exercise your rights and duties under the OHSA

The OHSA gives workers 3 important rights:

  • The right to know about hazards in their work and get information, supervision and instruction to protect their health and safety on the job.
  • The right to participate in identifying and solving workplace health and safety problems either through a health and safety representative or a worker member of a joint health and safety committee.
  • The right to refuse work that they believe is dangerous to their health and safety or that of any other worker in the workplace.

You can ask your workplace employer, supervisor, health and safety representatives, or joint health and safety committee about:

  • the substances or hazards that you are exposed to at work
  • documents such as exposure information or safety data sheets, and
  • what you and your employer must do to control or eliminate exposures, including how to safely and correctly use protective equipment.

Substances brought home accidentally

Substances that you encounter at work can be hazardous to your family, particularly children. For example, if you work with lead, it can be carried home on your clothing, on unwashed skin and on your personal protective equipment.

You can ask your workplace employer, supervisor, health and safety representatives, or joint health and safety committee about training and information about how to minimize the risk of this occurring. Your workplace may also be required to have certain types of measures and procedures in place, such as hygiene facilities that have sinks and showers to for you to clean yourself off before leaving the workplace.

If you’re concerned about substances that may be accidentally brought home, you should speak to your supervisor and workplace health and safety representatives. You can also contact our Health & Safety Contact Centre at 1 877 202-0008 on Monday to Friday, from 8:30 a.m. to 5:00 p.m., or webohs@ontario.ca.

Occupational Exposure Registry

The Occupational Exposure Registry (OER) Self-Tracker is a secure digital portal for workers to record and track their own exposure to hazardous substances in the workplace over the course of their employment.

For more information, please visit the Occupational Exposure Registry Self-Tracker.

Others outside of work who can help

Contact a doctor or nurse

If you are concerned about an exposure at work, you can bring the documents about the substances you work with to your doctor or nurse practitioner. They may:

  • suggest tests to help make a diagnosis
  • ask you about your job
  • ask you what you are exposed to at work

You can also ask your health care provider to refer you to a specialist with experience in occupational illness. You can also self-refer to one of the Occupational Health Clinics for Ontario Workers.

Submit a claim to WSIB

If you think your work made you sick, submit a claim for workplace safety and insurance benefits with the WSIB.

If you were exposed to a hazard but did not immediately experience any symptoms, you may still submit an exposure incident report to the WSIB. This creates a record of exposure in case you get sick in the future, which may help the WSIB assess a claim if you file one later.

The WSIB administers and enforces the WSIA.

Learn more about the Workplace Safety and Insurance Board.

Office of the Worker Adviser

The Office of the Worker Adviser provides free and confidential advice, education, and representation to non-unionized workers and their survivors. The Office of the Worker Adviser is an independent agency of the Ontario Ministry of Labour, Immigration, Training and Skills Development.

Information for employers

OHSA rights and duties

Employer duties under Sections 25 and 26 of the OHSA include general and specific things employers are required to do to protect their workers, including protecting workers from exposure to hazards that may result in occupational illness. For example, employers are required to:

  • accurately keep and maintain and make available to the worker affected records of the worker’s exposure to biological, chemical or physical agents as prescribed (s. 26 (1) (d) of the OHSA)
  • take every precaution reasonable in the circumstances for the protection of a worker (s. 25 (2) (h) of the OHSA)
    • This may include, for example, protecting the workers from workplace hazards
  • acquaint workers, and persons in authority over workers, with any hazard in the work and in the handling, storage, use, disposal and transport of any article, device, equipment or a biological, chemical or physical agent (s. 25 (2) (d) of the OHSA)

In addition to this, certain regulations such as the Designated Substances Regulation (O. Reg 490/09) require employers to take additional precautions, such as checking for the presence of designated substances in work processes and establishing control programs to protect workers who are exposed to these substances.

Report an occupational illness

Under s. 52 (2) of the OHSA, once you are advised, by or on behalf of a worker, that the worker has an occupational illness, or that a claim in respect of an occupational disease has been filed with the WSIB, you must give notice in writing within 4 days to:

  • a director of the Ministry of Labour, Immigration, Training and Skills Development
  • your joint health and safety committee or health and safety representative
  • your trade union, if any

The notice must include such information and particulars as are prescribed.

The duty to notify applies to current and former workers (as required under s. 52 (3) of the OHSA). 

You may also have reporting obligations other than providing notice under s. 52 (2) of the OHSA, for example, under other provisions of the OHSA or under other legislation such as the WSIA. The WSIB administers and enforces the WSIA. Get more details from the Workplace Safety and Insurance Board.

Office of the Employer Adviser

The Office of the Employer Adviser provides free and confidential advice, representation and education to employers. The Office of the Employer Adviser is an independent agency of the Ontario Ministry of Labour, Immigration, Training and Skills Development.

Information for health care professionals

Even though the OHSA mainly sets out duties for employers, supervisors, workers and others that are within the workplace, health care professionals play a key role in the prevention, early recognition and treatment of occupational illnesses (and occupational diseases).

By asking workers questions about the work they do and the substances they work with, you can help make an important link between what a worker may be exposed to at work, and the health effects that they may experience from doing that work later on.

You can ask patients if they would like to see a physician with expertise in the area, such as:

The North York General Hospital has a newly opened occupational health clinic that provides specialized expertise in investigating occupational illnesses.  Workers can be seen at this clinic with a referral from their family doctor.

North York General Hospital
4001 Leslie Street, 3N-300
Toronto, Ontario, M2K 1E1
Canada

Phone: 416-756-6686
Fax: 416-756-6891

Notify the Provincial Physician

You must notify the Ministry of Labour, Immigration, Training and Skills Development’s Provincial Physician if you are assessing workers as part of a control program for designated substances listed in O. Reg. 490/09: Designated Substances and you decide that a worker is either:

  • unfit to work with the designated substance
  • fit with limitations to work with the designated substance

For more information on best practices and requirements where you are assessing workers as part of a control program, you can look at guidance for examining physicians regarding designated substances.

Contact the Provincial Physician:

  • Phone: toll-free at  1-877-202-0008
  • Email: MLITSD.Provincial.Physician@ontario.ca
  • Mail:
    Ontario Ministry of Labour, Immigration, Training and Skills Development
    C/O Provincial Physician    
    Occupational Health and Safety Branch
    505 University Avenue, 19th Floor
    Toronto, ON
    M7A 1T7