As a result of the investigation, the agency has now imposed mandates for health and safety practices that previously were only recommended. It also expects to recommend more stringent limits on mist exposure.

It has changed the perception of risk arising from exposure to mist from metalworking in the U.K., said Sandra Caldwell, director of the Health and Safety Executives field operations. HSE is determined that workers elsewhere in this sector should get better protection against contracting these diseases, which have the potential to seriously impair the breathing and health of those affected by them.

Most of the sickened Powertrain employees were diagnosed with occupational asthma, extrinsic allergic alveolitis or both. (In the United States, extrinsic allergic alveolitis is referred to as hypersensitivity pneumonitis.) HSE said most cases developed in 2002 or later, with onsets peaking in March 2003. The agency launched its investigation a year later.

HSE tried to determine what caused the health problems by analyzing patients, testing for allergic reactions to various substances and inspecting their workplace. In an April 28 update on its investigation, HSE acknowledged that it does not know exactly what it was about the mist that triggered the diseases in workers. But officials said they did find links to bacteria and to used fluid.

Lead investigator Mike Burd told Lube Report that most of the stricken workers spent significant amounts of time in an area where exhaust from mechanical parts washers created large amounts of mist. The agency said that mist included old, contaminated metalworking fluid.

Burd added that investigators found no indication that microbacteria could have caused the outbreak, but he noted that endotoxins found in fluid were later found to trigger allergic reactions in some workers. Those endotoxins may have been byproducts of bacteria killed by biocides. HSE also checked for reactions to chemical ingredientsin the fluid but concluded they would not have been problematic at the levels present.

Prior to the Powertrain case, HSE typically received no more than five reports per year of industrial lung disease, and only isolated cases.It may be that some cases existed before but were not noticed, Burd said. But it is also possible that new risks are arising because of evolution in industrial practices – such as running machines at higher speeds or in more-enclosed areas.

As a result of its investigation, HSE now requires workplaces that use metalworking fluids to document assessments of the risks that they pose for causing occupational asthma and extrinsic allergic alveolitis. Employers must also establish means – such as use of dip slides – of directly monitoring bacterial contamination in metalworking and wash fluids. In areas where workers are exposed to mist, employers must conduct surveillance of their health.

Burd said HSE plans in coming months to adopt a recommended limit for mist exposure. He said the limit will probably be in the range of 0.4 to 0.5 milligrams/cubic meter during an eight-hour day. The United States has a mandatory limit of 5 mg/m3, but labor unions sued the federal government in 2003 for not adopting a cap of 0.5 mg/m3 recommended by the National Institute of Occupational Safety and Health.

HSE said it developed the new rules in cooperation with the United Kingdom Lubricants Association and manufacturers that use metalworking fluids. Agency officials said industry has cooperated well with the government, and UKLA representatives agreed.

Those of us who have been close to [workplaces that used metalworking fluids] were aware of the problems, said David Neadle, chairman of the UKLAs Metalworking Fluid Product Stewardship Group and a health and safety advisor to fluid supplier D.A. Stuart. We are in full cooperation with HSE on this effort.

The agency and association are in the process of developing a road show that will try to disseminate the new regulations and recommendations to manufacturers throughout the United Kingdom. One workplace that they will not have to worry about is Powertrain. The Longbridgefirm went out of business in 2005 for reasons unrelated to the outbreak. Its equipment was subsequently purchased by Nanjing Automobile (Group) Corp. and transferred to China.