UK workers were afforded far worse protection from the highly hazardous and cancer linked solvent methylene chloride (dichloromethane) than their US counterparts. Tighter standard were introduced in the US after a concerted 13-year union campaign. US regulator OSHA introduced a 25 parts per million (ppm) based on the assumption (subsequently proven) that methylene chloride may cause cancer in humans. In January 1998, autoworkers’ union UAW sued OSHA in the US Court of Appeals for the District of Columbia, seeking stronger protection for methylene chloride exposed workers. An industry group, the Halogenated Solvents Industry, also sued OSHA, objecting to the cost of the new standard. Soon after the lawsuits were filed, the UAW sought to develop with industry a mutually agreeable standard that would make it possible to end the litigation against OSHA. The resulting settlement was adopted by OSHA. The UK limit at the time was 100ppm, four times higher than the new US standard. HSE in 1998 reviewed its standard, but recommended not only a standstill standard, but a switch from a more binding Maximum Exposure Limit (MEL) to a less strict Occupational Exposure Standard (OES).

HSE’s poor solvent plan, Hazards, number 64, October-December 1998 [not online].

Dichloromethane – Exposure assessment document, EH74/1, HSE, August 1998.