Occupational Disease

August 15, 2017 at 12:10pm

Workers Comp Claims & Appeals: Occupational DiseaseInformation adopted from the Ontario Worker Adviser (OWA) website. Used with permission.

Occupational Disease includes:

  • Disease resulting from exposure to a substance relating to a particular process, trade, or occupation in an industry. This could include chemicals, dust, fumes or viruses. For example, asbestosis from exposure to asbestos in mining, manufacturing or construction.
  • A disease peculiar to, or characteristic of, a particular industrial process, trade or occupation. For example, operating drills used in mining or construction or tools such as chainsaws may result in Hand Arm Vibration Syndrome.
  • Medical conditions that, in the opinion of the WSIB, require that you be removed from exposure to a substance because the condition may lead to an occupational disease, or;
  • A disease mentioned in Schedule 3 or 4 of the Regulations to the Workplace Safety and Insurance Act, 1997. See more information about these schedules below.

If you suffer from and are impaired by an occupational disease, the WSIB will pay you benefits as if you were injured in a work-related accident. A special unit of WSIB known as the Occupational Disease and Survivor Benefits Program handles most occupational disease claims.

Why are the Scheduled Diseases Significant?

  • Schedule 3 contains a list of 30 diseases. WSIB will pay benefits if you prove you have one of these diseases and that you worked in a process listed next to that disease.
    • You will not receive benefits if either WSIB or your employer proves the disease did not arise from your work. For example, WSIB or the employer can argue that the workplace exposure to a substance was not long enough to be significant, or that other factors such as smoking were responsible for the disease.
  • Schedule 4 contains of list of only four diseases. To receive benefits for diseases listed in Schedule 4, you must prove that you have the disease and that you were employed in the listed work process.

What About Diseases That Are Not in the Schedules?

WSIB developed policy guidelines in an effort to decide claims relating to a number of other occupational diseases. For example, lung cancer among uranium or gold miners. Many of these guidelines set out minimum periods of exposure to substances such as radiation or arsenic. They also set out a minimum period between the date of first exposure and the diagnosis of the disease. This is called the latency period. Your exposure must meet these minimum periods in order to receive benefits.

If your claim does not meet the minimum requirements set out in the guidelines, or if there is no guideline relating to a particular disease and workplace exposure, WSIB will decide the claim based on the facts and evidence of your case.

The WSIB decision-maker will review:

  • Your medical condition,
  • Your exposure at work,
  • Up-to-date medical and scientific information, and
  • Possible factors not related to work.

Ultimately, the WSIB decides whether the workplace exposure made a significant contribution to the development of your disease.

What If I Worked As a Firefighter?

The Workplace Safety and Insurance Act has separate rules for firefighters who develop certain cancers. If you worked as a firefighter, contact the Workers’ Compensation Department (

When Should I File a Claim for Occupational Disease?

You should file a claim for occupational disease benefits:

  • As soon as possible. Preferably no later than six months from the date you discovered you have an occupational disease, if this happened on or after January 1, 1998. You should file a claim even if you missed the deadline. Occupational disease claims are complicated and the WSIB is more likely to extend the deadline for these types of claims.
  • As soon as your doctor diagnoses your disease, even if you are still able to work.
  • Even if your exposure to a dangerous substance happened with more than one employer. WSIB will usually treat the last of these employers as the accident employer. You may receive benefits even if you worked partly outside Ontario: As long as you can show that your exposure in Ontario was a significant contributing factor to the development of your disease.
  • If you are a spouse or the dependent of a worker who has died from an occupational disease.

You should speak to a UFCW Locals 175 & 633 Workers Compensation Representative (1-800-267-1977) before filing your claim.