Inhalation exposure of lead in brass foundry workers: the evaluation of the effectiveness of a powered air-purifying respirator and engineering controls.

The protection that a powered air-purifying respirator afforded to ladle and furnace attendants who were exposed to lead, copper and zinc fumes in a brass foundry was found by measuring metal levels at the lapel and at nose level inside the respirator. Respirator fit was evaluated by use of a hot-wire anemometer at the face/Tyvek seal interfaces, and at the exit of the respirator. Effective protection factors for lead ranged from 1.05 to 67. Ergonomic factors and engineering controls are also discussed.