Throughout the world, there are four billion gallons of metal working fluid made every year which get exposed to over a million employees. Safety is obviously a very important and very often the airborne concentrations of metalworking fluids are above the recommended levels. This can cause breathing and skin problems for workers, and could become a growing problem in third world countries where recommended exposure limits aren’t fully (if at all) adhered to.
The National Institute for Occupational Safety and Health (NIOSH) is the United States federal agency responsible for conducting research and making recommendations for the prevention of work related injury and illness. The equivalent body for the UK is the Institute of Occupational Safety and Health (IOSH). Both of these bodies recommend levels no greater thatn 0.5 mg/m3 for total metalworking fluid particulates for an average concentration of for up to 10 hours per day during a forty hour week. It is important that aerosol concentrations of metal working fluids be kept below these limits. Along with this, it is recommended that skin contact with metalworking fluids be kept to a minimum to prevent any irritant skin reactions and any allergic reactions. These irritations might come in the form of oil acne, rashes, ear nose and throat irritation, coughing, asthma or other breathing problems.
Many of these issues can be brought about by the use of straight oils, soluble oils, semisynthetic oils and synthetic oils used as part of the metal working lubrication process during grinding, cutting or boring articles. When these processes are done in the metal working lab or workshop, there is an increased chance of the worker inhaling aerosol metal working fluids, and an increased chance of skin splashes.
Inhaling airborne vapours are not the only way that metal working fluids can enter the body. If the fluids come into contact with the worker’s skin, there is a risk of absorbtion especially if there are cuts, rashes, cracks or other breaks in the skin. Obviously, hands, arms and perhaps faces are most at risk, and appropriate barrier methods should be incorporated into the workshop safety schedule to allow for this. Not only can fluids splash onto the skin during machining, but workers can also come into contact with metal working fluids when work pieces are handled, when tools are being changed and set, and during clean up operations. Any clothing or rags which are soaked with metalworking fluids can also be a concern.
Cancers often associated with exposure to metal working fluids include rectum, pancreas, larynx, skin, scrotum, esophagus, and bladder. The National Institute for Occupational Safety and Health (NIOSH) in the USA reports that studies were not highly consistent regarding the specific types of cancer associated with MWFs. This uncertainty is likely due to the wide variation in the types of MWFs and contaminants and the lack of detailed exposure information.
Keeping yourself safe when using Metal Working Fluids in the workshop
It’s really important to obtain the Material Safety Data Sheet so you know exact make up of the metal working fluid that you are working with. Also keep up to date with technical bulletins both from the IOSH and the NIOSH and ensure that exposure control measures are implemented. Ensure that you choose metalworking fluids with the least toxic materials whenever possible.