Occupational illness can look the same as other illnesses or diseases. For example, somebody with work-related asthma might have the same signs and symptoms as any other person with asthma.

When you are exposed to something that could affect your health at work, sometimes the effects are sudden and obvious. Other times, the effects might take months or years to develop.

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 prevent occupational illness by minimizing or eliminating exposure 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 identify workplace hazards such as:

  • products being used, such as chemicals and hazardous substances
  • processes that happen, such as working with particular tools or tasks

After a committee or representative identifies a hazard, they can make recommendations to the employer on how to control workers’ 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 set of practices an employer can consider to protect workers from exposure. The controls are considered, in order, from most effective and protective to the least effective and protective.

  1. Elimination or substitution: Remove or change substances or processes that could be harmful.
  2. Engineering: Design the work area to reduce exposure to hazards (for example, install ventilation or barriers).
  3. Administrative controls: Provide training and supervision on how to avoid exposure to hazards and limit exposures through work scheduling and breaks.
  4. Personal protective equipment: Have workers wear protective gear, such as respirators to prevent them from breathing in hazardous substances.

Occupational Health and Safety Act and regulations

Everyone in the workplace has the right to know about how to control their exposures at work and find information on the hazards they work with.

Laws and regulations ensure that hazard information is shared. Read up on the rights described in the Occupational Health and Safety Act (OHSA) and the regulation for Workplace Hazardous Materials Information Systems (WHMIS).

Other regulations important for protection from workplace exposures include, but are not limited to:

Where to get help

These health and safety associations offer specialized services and provide support to workers and employers to help address workplace hazards to prevent occupational illness:

Information for workers

As a worker, you should know and exercise your rights and duties.

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.

If you are concerned about an exposure at work, bring the documents about the substances you work with to your doctor or nurse practitioner. They may suggest tests to help make a diagnosis and may want to ask you more about your job and 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.

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.

Workplaces that use hazardous substances must provide you with training and information about how to minimize the risk of exposure. Employers may also need to provide hygiene facilities for you to decontaminate yourself from hazardous substances.

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.

Contact the Workplace Safety and Insurance Board (WSIB)

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

The following organizations offer assistance with WSIB issues and claims.

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.

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 employers

As an employer, you have a duty to protect your workers from hazards in the workplace that could make them sick.

Duties under Sections 25 and 26 in the OHSA include a mixture of general and specific things employers need to do to protect their workers, such as:

  • checking levels of designated substances in work processes
  • establishing control programs to protect workers who are exposed
  • maintaining worker exposure records
  • providing safety-related medical examinations and tests
  • take every precaution reasonable in the circumstances to protect the worker (from workplace hazards)
  • make sure workers and supervisors are aware of any hazard that they might encounter in the workplace including biological, chemical or physical agents

Report an occupational illness

Once you become aware that a worker has an occupational illness, or that a claim for an occupational disease has been filed with the WSIB, you must report within 4 days to:

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

The duty to notify applies to current and former workers (for example, those who may have left the workplace).

Information for health care professionals

As a health care professional, you play a key role in the prevention, early recognition and treatment of occupational illnesses (and occupational diseases).

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

St. Michael’s Hospital Department of Occupational and Environmental Health also provides clinical support for investigating occupational illness and workers can be seen at this clinic with a referral from their family doctor.

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

Contact the Provincial Physician:

  • Phone: toll-free at 1-877-202-0008
  • Email: MLTSD.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