A 2-year HSE investigation at the Powertrain Ltd. car plant in Longbridge, Birmingham, has convinced the agency that the cause of the outbreak was mist from metalworking machines. Sandra Caldwell, director of HSE's Field Operations, said that the outbreak is believed to be both the world's largest linked to metalworking fluids and the largest single outbreak of occupational asthma.
"It has changed the perception of the risk arising from the exposure to mist from metalworking in the U.K.," Caldwell said " … While we do not know the precise agent within the mist that triggered the outbreak, we did find links to bacteria, and used metalworking fluid. Other possible causes, such as metals leaching into the mist from the machining and washing of components, have been closely investigated and are thought unlikely to have caused the outbreak."
HSE's investigation began in March 2004, and to date, 101 workers at the former car plant have been diagnosed mainly with either occupational asthma or extrinsic allergic alveolitis. Both diseases cause breathing difficulties, which are severe and in some cases can be long-lasting.
HSE served three improvement notices to Powertrain Ltd. in 2004 once the scale of the outbreak became apparent. The company went into bankruptcy in 2005 and the assets were subsequently sold to Nanjing Automobile (Group) Corp. and removed to China. No further action is proposed by HSE.
Guidance Reflects Increased Risk
As a result of the outbreak, HSE has updated its guidance on metalworking. In light of the increased risk revealed by the outbreak, the agency's guidance points out that:
- Risk assessments must deal with the risks of occupational asthma and extrinsic allergic alveolitis.
- Direct means of monitoring bacterial contamination in metalworking and wash fluids, such as dip slides, must be used.
- Exposure to mist needs to be prevented or better controlled. Health surveillance must be carried out where there is exposure to mist.
The guidance has been developed with the help of experts both within and outside HSE and in conjunction with other stakeholders. Longer-term investigations and research into aspects of the outbreak continue.
Online Resources Offered, Roadshows Planned
HSE also is checking standards at other large companies. Conditions have varied, the agency says. Where there has been cause for concern, HSE inspectors have served improvement notices. A report on this intervention will appear at http://www.hse.gov.uk/metalworking.
A questionnaire to help firms determine whether they are properly assessing risks is available at http://www.hse.gov.uk/metalworking/questionnaire.pdf.
For smaller companies, a series of roadshows will take place across the United Kingdom over the next 2 years. These are being organized in conjunction with the United Kingdom Lubricants Association Metalworking Fluids Product Stewardship Group. HSE inspectors will conducts follow-up visits to those employers who don't attend to ensure the messages are getting through.
"HSE is making available the lessons learned from the outbreak and has taken action to prevent a recurrence," Caldwell said. "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."
"Outbreak of Respiratory Disease at Powertrain Ltd., Longbridge, Birmingham Emerging Lessons" can be found at http://www.hse.gov.uk/metalworking/experience/powertrain.pdf.