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Metalworking fluids

Metalworking fluids can cause health problems such as infections and asthma. The fluids contain a variety of different chemicals and oils and may be full of bacteria. Workers could inhale vapours or get fluid on their skin. Practising good hygiene will help protect workers from exposure to metalworking fluids.

How workers are exposed

Many industrial operations, such as grinding, cutting, or boring metal, use metalworking fluids. Workers can be exposed by breathing in the vapour, by getting the fluids on their skin, or by ingesting them. Fluid on a worker's face or hands can make its way onto food if workers don't wash up before they eat.

The risks

How workers are exposed to metalworking fluids determines the health issues that may result. Here are the potential health problems:

Inhalation (vapour)
  • Chronic bronchitis
  • Impaired lung function
  • Asthma
  • Hypersensitivity pneumonitis
Skin contact (liquid)
  • Infections
  • Oil acne
  • Folliculitis
  • Irritation and allergic dermatitis

Workers exposed to metalworking fluid aerosols have an increased risk of non-malignant respiratory disease and skin cancer. Water-based metalworking fluids may contain bacteria.

Metalworking fluids can contain a variety of ingredients, including:

  • Oil
  • Emulsifiers
  • Anti-foaming agents
  • Anti-weld agents
  • Corrosion inhibitors
  • Preservatives
  • Biocides

How to reduce the risks

Good hygiene can help protect workers from exposure to metalworking fluids. Washing hands and face before eating and smoking will help prevent workers from ingesting or inhaling the fluids. Work clothes should be stored away from personal clothes to prevent contamination.

The best way to reduce the risk of exposure to metalworking fluids is to eliminate the source of exposure. If that's not possible, there are other risk controls to use. These should be identified in your exposure control plan. When choosing risk controls, start by asking the questions in the following steps. The steps are listed in order of effectiveness.

  1. 1

    Elimination or substitution

    Eliminating the hazard by substituting a safer process or material, where possible, is the most effective control. Some questions to consider:

    • Can a less hazardous material be used in the fluid?
    • Can a process that generates less fluid vapours or spills be used?
  2. 2

    Engineering controls

    Making physical modifications to facilities, equipment, and processes can reduce exposure. Some questions to consider:

    • Can the work process be automated to eliminate workers being exposed?
    • Can you enclose the equipment?
    • Can general or local exhaust ventilation be provided or improved?
    • Can equipment be modified to reduce the spray of metalworking fluids and mist (e.g., by installing splashguards)?
  3. 3

    Administrative controls

    These involve changing work practices and work policies. Awareness tools and training also count as administrative controls. All can limit the risk of metalworking fluids exposure. Some questions to consider:

    • Can warning signs be posted in the work area?
    • Can a hygiene awareness program be implemented?
    • Do workers change their contaminated clothing every day?
    • Has a skin care program been established that addresses washing, conditioning, and barrier creams?
    • Have workers been trained to recognize the symptoms of over-exposure and respond with the appropriate controls?
    • Can eating areas be located away from the worksite, and have a washing station?
  4. 4

    Personal protective equipment

    This is the least preferred control. When used, there must always be at least one other control in place as well. Some questions to consider:

    • Do workers have the proper respirators, eye wear, and protective clothing?
    • Have workers been fit tested to ensure their respirators work effectively?
    • Has personal protective equipment been verified to ensure it is working properly?