What are Moulds?

Moulds are microorganisms that can grow on virtually any substance, indoor and outdoor, as long as moisture, oxygen, and an organic source are present.

How do moulds affect the health of workers?

Moulds produce thousands of tiny particles called spores as part of their reproductive cycle. When disturbed by air movement or contact, moulds release these spores into the air. The inhalation of spores, moulds or mould fragments can affect your health or make certain health conditions worse.

Workers exposed to mould can have different symptoms. Some may have no reaction at all. The most common effects of mould exposure are:

  • Irritation to the skin, eyes, nose, throat
  • Burning in the nose, nosebleeds
  • Difficulty breathing, asthmatic attacks
  • Watery eyes, runny nose
  • Nausea
  • Headaches
  • Fatigue, difficulty concentrating
  • Impairment of the immune system

How are mould hazards identified?

Visual inspections are the most reliable method of identifying mould problems. When conducting a visual inspection, look for signs of water damage such as discolouration and staining. Air sampling, surface sampling and bulk sampling (taking bits of drywall, flooring, etc.) are also methods used to identify the presence of moulds.

How to prevent moulds from forming in your workplace

The following can help prevent mould growth in your workplace:

  • Keep relative humidity in the workplace between 30 and 60 per cent.
  • Conduct regular inspections and be diligent, particularly if you work in a sewage treatment plant or composting facility.
  • Make sure landscaping and eavestrough downspouts direct water away from buildings.
  • Ensure any high moisture areas are properly ventilated with local exhaust ventilation that captures the moisture and directs it out of the building.
  • Get employers to insulate cold surfaces to prevent condensation on pipes, windows, walls, roofs and floors.
  • Perform regular maintenance and cleaning of heating, ventilation and air conditioning systems.
  • Perform regular maintenance of buildings, especially roofs, basements and other locations where leaks occur.

What should you do if there is mould in your workplace?

Mould should be reported to management immediately. If the problem is not immediately rectified, report it to your health and safety committee.

Fixing a mould problem includes identification and correction of the condition that allows the mould to grow, and safe removal of materials damaged by mould. Appropriate personal protective equipment and training (based on the size of the problem) should be provided before remediation begins. The cleaning and removal process depends on the size and type of mould growth, the extent of the damage, and the location. 

Aug 10, 2006 Health and Safety