Dermal exposure to metalworking fluids and medium-chain chlorinated paraffin (MCCP)

Metalworking fluids (MWF) may contain a variety of additives, including medium-chain chlorinated paraffin (MCCP). There is concern that exposure to MCCP may be associated with increased risks for kidney toxicity. MCCP has been undergoing an evaluation as part of a European regulatory risk assessment and consequently it is important that an estimate is made of the likely occupational exposure. This paper reviews the available published data on dermal exposure to MWF and derives typical and reasonable worst-case (RWC) estimates of MCCP exposure. Estimates were highest for oil-based fluids (520 and 35000 mg typical daily exposure and RWC exposure, respectively) and lowest for water-based fluids (30 and 520 mg for typical and RWC, respectively). Comparison with published inhalation exposure data suggests dermal and inhalation exposure may be of comparable magnitude.