Issue: On 2/3/06, ACGIH^® released a draft version of a TLV recommendation for “Mineral Oil Used in Metal Working” (occupational exposure to mineral oil aerosols in metal working operations where additives and metal or microbial contaminants are present.”) When used in metalworking situations, the draft TLV^® proposes a reduction from 5 mg/m3 to 0.2 mg/m3, time-weighted average (TWA). For “pure” mineral oil, the TLV^® remains at the current 5 mg/m3 TLV-TWA.

This distinction suggests that the alleged health effects of mineral oil in metalworking operations are due to constituents other than highly refined mineral oil – the additives, microbial contaminants and small pieces of metal commonly known as “fines” or “swarfs” generated by the metalworking process.

The American Conference of Government Hygienists (ACGIH^®) is a group committed to providing industrial hygiene and occupational hygiene education and training to its members. ACGIH^® determines Threshold Limit Values (TLVs^®). However, TLVs^® are not standards. Additionally, they are developed in a non-consensus way (closed, secretive process.) They are guidelines designed for use by industrial hygienists in making decisions regarding safe levels of exposure to various chemical substances and physical agents found in the workplace. In using these guidelines, industrial hygienists are cautioned that the TLVs^® are only one of multiple factors to be considered in evaluating specific workplace situations.

Unfortunately, the literature cited in the ACGIH^® scientific analysis does not support their proposal. Most importantly, the preponderance of evidence suggests that respiratory impacts experienced by machinists in the studies are not due to mineral oil, but to a combination of other causes including microbial and microbial decay products, irritation from specific chemical components. Additionally, no generally available test procedure exists that would permit an industrial hygienist to even know whether a 0.2 mg/m3 is being achieved in any occupational setting.

By proposing to dramatically lower the TLV^® for mineral oils used in metalworking, ACGIH misses the significant opportunity to focus the resources of the organization on what might be truly causing the adverse health effects sometimes observed – that is, microbial contamination.

Under the Hazard Communication (HazCom) Standard, OSHA automatically adopts the latest final version of ACGIH’s TLV^® list every year and requires that manufacturers (Quaker and all it’s competitors) list the latest TLV limits on any Material Safety Data Sheet (MSDS) that they generate for use in the work place.

American Conference of Government Industrial Hygienists (ACGIH)

American Conference of Government Industrial
Hygienists (ACGIH)