Bio-hazards, occupational diseases and hepatitis B

Last updated: August 11, 2021

An occupational disease is caused by exposure to hazardous substances in the workplace. These include contaminated blood or bodily fluids carrying:

  • HIV
  • Hepatitis B
  • Tuberculosis
  • Whooping cough
  • Influenza 

Managers must determine if employees are at risk of exposure to an infectious disease. If there's a risk of exposure to any hazardous substance, you must develop an exposure control plan that notes:

  • The job duties that may expose employees at risk
  • Who's at risk and  what the disease or infection may be
  • How the disease is transmitted
  • Risk level
  • Control measures to protect staff

The Guide to the Prevention and Control of Infectious Diseases in the Workplace (PDF, 6.3MB) explains when and how to create an exposure control plan. Ask your employees about possible exposures.

Once you've completed a plan, train at-risk employees on control measures. Employees must report all possible exposures. The plan must be reviewed annually (at least) or whenever working conditions change to influence exposure or introduce new exposures.

Hepatitis B

Hepatitis B is an infectious liver disease. It is caused by the hepatitis B virus. Infections only occur if the virus enters the blood stream and reaches the liver. Hepatitis B is not transmitted by casual contact. For example, hospital employees who have no contact with blood, blood products or blood-contaminated fluids are at no greater risk than the public.

Blood is the major source of the hepatitis B virus in the workplace. It can be found in other tissues and body fluids, but in much lower concentrations. Direct contact with infected blood can transmit the hepatitis B virus through:

  • Skin punctures with blood-contaminated needles, lancets, scalpels or other sharp objects
  • Splashes on skin with minute scratches, abrasions, burns or even minor rashes
  • Splashes on mucous membranes in the mouth, nose or eyes

Saliva can contain the virus, but in very low concentrations compared to blood. Infected saliva can transmit the virus, so bite injuries can spread the disease.


Supervisors must determine the risk of hepatitis B. Employees at a greater risk than the public can get vaccinated at the employer's expense.

All first aid attendants meet the criteria for immunization.

To determine the risk of hepatitis B exposure:

A Hepatitis B Immunization Record (PDF, 46KB) is required for all designated first aid attendants. The record confirms the vaccination has been completed or offered. The record notes whether the employee accepted or declined immunization.

How the vaccination works:

  1. If you're at risk of exposure to hepatitis B, you receive a series of three vaccinations. The attending nurse signs the Hepatitis B Immunization Record (PDF, 46KB)
  2. When the three vaccinations are finished, photocopy the record. Provide copies to your supervisor and to Occupational Health and Rehabilitation. Keep a copy for your records
  3. You'll receive a lab requisition to have your blood tested six to eight weeks after the third injection. The test makes sure you're protected
  4. Occupational Health Programs will contact you if the vaccination series has not been successful
  5. You submit vaccination receipts to your supervisor for reimbursement