Exposure to metalworking fluids can cause; irritation of the skin/dermatitis, occupational asthma, bronchitis, irritation of the upper respiratory tract, breathing difficulties or, rarely, a more serious lung disease called extrinsic allergic alveolitis.

What are metalworking fluids? Image courtesy of HSE

Metalworking fluids (MWFs) - sometimes referred to as suds, coolants, slurry or soap are used during the machining of metals to provide lubrication and cooling.


Main health risks from working with MWFs

  • respiratory disease, for example Occupational Hypersensitivity Pneumonitis (OHP) and occupational asthma (from water-mix MWFs)
  • dermatitis

How can MWFs affect you?

Mostly applied by continuous jet, spray, or hand dispenser – they can affect you:

  • if you inhale the mist, aerosol or vapour generated during machining operations
  • through contact with the skin, particularly hands and forearms, if appropriate precautions are not taken (for example the use of gloves, overalls or face shields)
  • by entering your body through cuts/broken skin
  • by entering your body through the mouth if you eat or drink in work areas, or do not wash your hands before eating or smoking

Control of Substances Hazardous to Health Regulations (NI) 2003 requires exposure to metalworking fluids by inhalation, ingestion or skin contact to be prevented where reasonably practicable, or failing that, adequately controlled.

You should:

  • carry out a suitable and sufficient risk assessment of the risk to health from exposure to MWFs
  • as an employer apply the principles of good practice in Schedule 2A of the COSHH Regulations to achieve adequate control
  • reduce to as low as is reasonably practicable exposure to substances that cause occupational asthma
  • carry out health surveillance where necessary


Key Legislation