LEARNING TASK 3 : Describe long-term hazards in the trades

Airborne hazards

Some job tasks may expose you to dust or gases that can make you sick or damage your lungs if you breathe them in. These materials can enter the bloodstream and travel to other parts of your body as well. If there is a hazard of airborne material in the workplace, a risk assessment should be conducted and if necessary, an exposure control plan must be implemented.

Dust

Health hazards are not limited to hazardous materials. For example, inhaling wood dust without proper protection can cause permanent lung damage even though wood is not a hazardous material. Dusts are fine particles that can remain suspended in the air and are less than 10 micrometers in size. Typical dust masks remove 95% of particles 0.3 microns in size or larger.
When hazardous dusts are present in the workplace, WorkSafeBC recommends taking the following actions (in order of importance):

  • Control the production of hazardous dust by changing the process that produces it.
  • If the process cannot be changed, install adequate ventilation to control the dust.
  • If the dust cannot be controlled, restrict access to the area where the dust is present.
  • If workers are required to work in areas where hazardous dust is present, they must wear appropriate personal protection. The use of an appropriate respirator for the conditions will ensure the worker’s safety.

The above actions are ordered by level of long-term safety for the workers. Simple dust masks are not adequate to prevent injury from hazardous dusts. Respirator-type masks with double head straps suited to the type of dust must be used.

See Competency A-4, Describe Personal Safety Practices for more information on respirators.

Airborne fibres

Particles classed as airborne fibres are larger than particles in the “dust” class. Both dusts and fibres are carried in the air. Airborne fibres can be even more dangerous than the finest dusts. The composition of the fibres is the factor that determines the hazard—fibres from wood are irritants, while asbestos fibres are linked to lung cancer.

Asbestos

Asbestos is a fibrous material that was used in many products up until the late 1980s because it added strength, heat resistance, and chemical resistance. During the past 20 years, exposure to asbestos is more common when old asbestos is removed or otherwise disturbed, rather than situations where new asbestos is installed. Workers repairing or renovating an old building may be at risk of exposure to asbestos used in the construction of that building. Asbestos is a very hazardous material and requires extreme safety precautions. Its fibres are extremely fine and can stay in the air for hours. Workers exposed to asbestos-contaminated air can inhale these fibres. If handled without caution, asbestos can cause the serious condition known as asbestosis.Asbestosis is a chronic lung disease resulting from prolonged exposure to asbestos fibres. The fibres gradually cause the lung to become scarred and stiff, making breathing difficult. Lung cancer may be caused by asbestos fibres in the lung.For more information on working safely around asbestos, see the WorkSafeBC manual, Safe Work Practices for Handling Asbestos.
Watch the WorkSafeBC video “Asbestos“.

Mould

Mould can grow quickly on damp materials such as cardboard, paper, wood, and drywall. As mould grows, it releases spores into the air. Exposure to mould spores can affect your health, especially if you have allergies, asthma, or a weak immune system.

Watch the WorkSafeBC video “Mould Exposure“.

Toxic Metals

The term heavy metals generally refers to the toxic metallic elements:

  • lead
  • mercury
  • arsenic
  • cadmium

These metals, or compounds containing these metals, tend to build up in the bodies of living organisms over a long period of time. Eventually the concentration of the metals reaches a point where they become toxic and pose a significant health hazard. These heavy metals can get into our bodies when we inhale contaminated dusts or ingest foods that have been exposed to or contain toxins.

Lead

Lead is a heavy metal occasionally found in old paint or plumbing solder. Sanding painted surfaces that contain lead produces airborne lead dust. Workers exposed to this dust risk inhaling it and may suffer from lead poisoning if proper safety precautions are not taken. Although lead has not been used in interior paints since the 1950s, refinishing lead-painted wood is still a significant hazard. Symptoms of lead poisoning include:
  • digestive discomfort, constipation, anorexia, nausea
  • fatigue, weakness
  • personality change
  • headache
  • hearing loss
  • tremor, lack of coordination

Mercury

Mercury is a heavy metal that was previously used in switches, fluorescent light bulbs, and many other applications. In 1990, elevated levels of mercury were found in persons exposed to interior latex (water-based) paint containing phenyl mercuric acetate, a preservative used to prolong the paint’s shelf life. Symptoms of mercury poisoning include:
  • muscle cramps or tremors
  • headache
  • intermittent fever
  • personality change

Regardless of whether paint is new or old, latex- or oil-based, always wear a respirator to prevent inhaling hazardous paint dust or vapours when sanding a painted surface.

Arsenic

Arsenic is a heavy metal used in wood preservatives. Workers who are in contact with wood preservatives or pre-treated wood must follow the precautions outlined for the product.

Cadmium

Nickel cadmium (NiCad) batteries contain cadmium, a highly toxic heavy metal. Always read manufacturer’s instructions when charging and disposing of NiCad batteries. As long as NiCad’s are kept sealed and are never short-circuited or severely overcharged, NiCad batteries are perfectly safe to use and do not vent toxic material. Cadmium can also be found in older brazing material as well as stainless steel electrodes.

Vapours and gases

A gas is a low-density chemical compound that normally fills the space in which it is released. It has no physical shape or form. Vapour is a gas produced by evaporation. Workplace tasks can produce several hazardous vapours and gases. Ultraviolet radiation, surface coatings, shielding gases, and welding electrode coatings are some sources of vapours and gases.

Off-gassing

Off-gassing is the release of chemicals from non-metallic substances. As an example, off-gassing is responsible for the distinctive “new car smell” in new automobiles. Anytime there’s an odour from a substance, that’s off-gassing. However, some off-gassing is odourless, which makes detection difficult. Many new construction materials have an off-gassing period in which they emit volatile organic compounds (VOCs). VOCs are chemicals that often come from various household products like paints, lacquer, printers, pesticides, cleaning supplies, carpets, and adhesives. VOCs are known to cause nose and throat irritation, headaches, nausea, and even damage to the central nervous system. You should always increase ventilation during the period of VOC off-gassing and consider using an air purifier.

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Trades Access Common Core | Line A: Safe Work Practices | Competency A-1 Copyright © 2021 by Camosun College is licensed under a Creative Commons Attribution 4.0 International License, except where otherwise noted.

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