Inspection Detail

Inspection: 300441557 - Dartmouth College

Inspection Information - Office: Concord Area Office

Investigation Summary

Employee #1 was a professor in a college chemistry department. Her research focused on the toxicity of metals, particularly chromium and cadmium. While on sabbatical, she was involved in a research project on the role of metals in the inhibition of DNA repair, and this expanded to include studies of mercury. The interactions of the compounds were studied using nuclear magnetic resonance. For the mercury-containing compounds, the reference standard was prepared: dimethyl-mercury, which was used in pure form. On approximately August 14, 1996, Employee #1 spilled a few drops of dimethyl-mercury on the back of her gloved hand while the chemical was being transferred between containers. She promptly cleaned up and did not think any more about it. This was the only time the material was handled outside of a closed container. The first symptoms did not occur until November 1996, and they were ascribed to gastroenteritis. Neurological symptoms appeared in January 1997, and Employee #1 died on June 8, 1997, of organic mercury poisoning. A lapse time between exposure and the appearance of symptoms is characteristic of alkyl mercury poisoning. The amount of the chemical that was absorbed into her body was estimated to be less than one-tenth of a milliliter (approximately 300 mg), or the equivalent of a single small droplet. Dimethyl-mercury is absorbed through the skin and is potentially lethal in small doses. Since the exposure appeared to have occurred through Employee #1's gloves, the college sent six samples of the disposable gloves used in the laboratory to Intertek testing services for permeation testing. All six samples failed, with breakthrough occurring in 15 to 30 seconds. Disposable latex gloves were routinely used in the lab due to the dexterity with which items could be handled. Although they are not intended by the manufacturer for chemical use, for many of the chemicals handled in Employee #1's lab, they would have provided adequate protection from the occasional contact due to drips or spills. They would not be adequate for use with organic chemicals. There was little training on how to choose gloves, and there was no discussion of permeability or other issues affecting use with different chemicals during the annual chemical hygiene training. Employee #1's death by organic mercury poisoning was directly attributable to use of the wrong kind of gloves for the chemical involved.

Keywords: PROTECTIVE CLOTHING, PPE, GLOVE, WORK RULES, SKIN, SPILL, POISONING, UNTRAINED, CHEMICAL