About metalworking fluids
Metalworking Fluids (MWFs) are neat oils or water-based fluids used during the machining and shaping of metals to provide lubrication and cooling. They are sometimes referred to as suds, coolants, slurry or soap.
Exposure to metalworking fluids can cause:
- irritation of the skin or dermatitis; and
- occupational asthma, bronchitis, irritation of the upper respiratory tract, breathing difficulties or, rarely, a more serious lung disease called extrinsic allergic alveolitis (EAA), which can cause increasingly severe breathing difficulties in recurrent episodes, following repeated exposure.
Fluid and mist from water-mix wash fluids and washing machines used to clean machined components may be hazardous in much the same way as fluid and mist from metalworking machines, and the same principles of risk assessment, prevention and control should be applied.
How harm is caused
Metalworking fluids are mostly applied by continuous jet, spray or hand dispenser and can affect your health:
- if you inhale the mist generated during machining/shaping operations;
- through direct contact with unprotected skin, particularly hands, forearms and heads;
- through cuts and abrasions or other broken skin; and
- through the mouth if you eat, drink or smoke in work areas, or from poor personal hygiene, eg not washing hands before eating.
Control of Substances Hazardous to Health Regulations (COSHH) requires exposure to metalworking fluids by inhalation, ingestion or skin contact to be prevented where reasonably practicable, or failing that, adequately controlled.
- carry out a suitable and sufficient risk assessment – HSE’s self-assessment questionnaire will help you do this;
- maintain fluid quality and control bacterial contamination of fluids;
- minimise skin exposure to fluids;
- prevent or control airborne mists; and
- where there is exposure to fluid or mist, carry out health surveillance.
To achieve the necessary control and risk reduction, among other actions, you will need to:
- check and maintain exposure control measures, such as enclosures and local exhaust ventilation;
- check levels of bacterial contamination using dip slides, or other means of measuring the level of bacterial activity, in both metalworking and associated fluids eg in washing machines, and act on the readings obtained in line with your risk assessment;
- ensure that, as a minimum, a responsible person carries out the required health surveillance
- conduct asthma health checks
- refer anyone affected by exposure to a competent occupational health professional;
- take prompt action after any diagnosis of ill health to identify the likely cause and ensure it is prevented or adequately controlled; and
- keep workers informed of all findings.
Working safely with metalworking fluids: A guide for employees
- Working safely with metalworking fluids: A guide for employees
- Good Practice Guide for Safe Handling and Disposal of Metalworking Fluids