In an apparently unprecedented action, the Virginia Workers' Compensation Commission ruled that an operating engineer's severe neurologic symptoms – including problems with vision, memory loss, tremors, dizziness, difficulty speaking, and disorientation – were related to exposures on the job to fumes from hydraulic fluid. The fluid contained an organophosphate. Organophosphates are used to improve lubricating quality, but they have been used also as insecticides and can damage the nervous system.

Representing himself in a legal proceeding before the commission, John Edward Gentry of Culpeper, Va., won medical benefits beginning Sept. 28, 1998, a date 15 days before a diagnosis of work-related organophosphate poisoning by Laura Welch, MD, of the Washington (D.C.) Hospital Center. The award, against Prince William Construction Inc., of Manassas, Va., and the Phoenix Insurance Company, of Chantilly, Va., a subsidiary of Travelers Insurance Company, was for symptoms first treated by emergency room doctors on April 30, 1998.

The legal opinion, which was upheld when it was reviewed, stated that Gentry had identified "a compensable occupational disease." Studies of hydraulic fluids used in aircraft have shown that, when such fluids touch a hot exhaust system, toxic chemicals can be produced, including carbon monoxide, according to Chris Van Netten, PhD, of the University of British Columbia, in Canada. Still, the Gentry case may be the first worker's comp decision confirming a connection between construction work and illness caused by organophosphate exposure.

Gentry had been operating a front-end loader with an open cab, part of the time in a hole. Beginning April 1, he noticed hydraulic fluid leaking over the hot engine, although he did not notice an odor or experience symptoms right away. On April 30, he blacked out on the job and was taken by ambulance to a local hospital. Gentry, a military veteran who had previously been healthy, suffered two more incidents related to oil leaks, in June and in October, the last while working for another employer.

According to the review opinion, one doctor for the defendants claimed that high anxiety caused many of Gentry's symptoms following the April exposures and another doctor concluded that the operator's symptoms stemmed from a psychiatric disorder unrelated to fumes. Reached in December, the lawyer and a spokeswoman for the construction company said they still doubted there had been a work-related problem. A spokeswoman for Travelers Insurance said, "We are fully prepared to honor our obligations."

Dr. Welch's report said a blood test for carbon monoxide or organophosphate poisoning would have had to have been done at the time of exposure; Gentry said no blood test was done.

Identifying hazards on the job can be difficult. Read the MSDS carefully. An MSDS or a label may not always list all the chemicals in a product. The MSDS in this case listed the components only as "lubricating oil base stock" and "proprietary additives." But, small print gave warnings, such as, "Use supplied air breathing equipment for enclosed or confined spaces..." and "Carbon monoxide and other unidentified organic compounds may be formed upon combustion."

To protect yourself from potentially toxic chemicals, avoid skin contact and avoid inhaling fumes. Wash well before eating or smoking. Wash your work clothes apart from other clothes. You may want to wear goggles or special gloves. Keep the machinery in good condition to prevent leaks and overheating. To learn more, go to ATSDRIC@cdc.gov or call 1-888-422-8737. Or, to find an occupational clinic near you, check www.aoec.org