For engineering workers the common causes of asthma are metalworking fluids (MWFs). 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. MWFs are mostly applied by continuous jet, spray or hand dispenser.
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.
Exposure to MWFs can cause 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.
Control of Substances Hazardous to Health Regulations (COSHH) 2002 (as amended) require exposure to MWFs by inhalation, ingestion or skin contact to be prevented where reasonably practicable or, failing that, adequately controlled.