A systematic review of human health risks associated with metalworking fluids exposure

Metalworking fluid (MWF) is the name given to a range of oils, emulsions and other fluid used in metalworking processes to reduce friction, heat, rust, and evacuate swarf. However, most of these fluids are based on finite resource - mineral oil and contain biocides, thus representing an environmental threat at each life cycle stage from resource extraction to disposal. The basic methodological approach of this research was based on the systematic review of relevant academic literature in the field of health issues caused by MWF application. An academic electronic reference source was queried for the related terms while search engine was set to sort the results by relevance. Based on the systematic literature review, this study has identified and noted 31 reports in the peer reviewed literature directly relevant to human health risks associated with MWF exposure effects. The majority of these studies were case series and cross-sectional studies of which 13 addressed malignant diseases; 7 respiratory effects; 6 skin effects or allergies; and 7 pathogenic microbial contaminants. The major studies identified excess malignant diseases including lung, liver, skin, pancreatic, and laryngeal cancer in cohorts exposed to MWF. In addition, a strong association has been established with asthma and hypersensitivity pneumonitis. The research did not categorise the results according to the MWF formulation, nor according to the method of application.