Air Respirator Reduces Foundry's Eye Injuries.

Ward Manufacturing, a 1050-employee caster of gray and malleable iron pipe fittings and unions, has reduced worker eye injuries and boosted productivity with the use of an air respirator system. The green sand foundry's chief respiratory challenge is silica dust emitted during its pipe fabrication operations. In 1993, the Blossburg, Pennsylvania-based plant converted from a wet to a dry system, in which the fittings coming from the molds had to be handled with the silica dust still on them.

"An engineering control system designed to capture the silica dust didn't meet our expectations," said Craig Johnson, health and safety manager. "The dust problem would occur after the fitting was poured. Dust rides through the system until the fitting is broken from the mold. The majority of sand is removed for reuse, and the finished fitting travels to another department for finishing, but small amounts of sand cling to the fitting due to its high temperature. As the pipe fitting cools, sand breaks free, falls to the vibrating table and then rises into the air."

Employees wore filtering face-piece respirators to protect them from the dust because the concentrations were well below the permissible exposure limit. Although these respirators were comfortable, lightweight and easy to use--and despite the safety glasses employees wore--there was a rash of eye injuries due to circulating airborne silica dust. The dust also settled on employees' hair and eyebrows, so when they went home at the end of the day and took a shower, they would wash the silica dust into their eyes.

"The problem was two-fold," Johnson said. "First, the protective equipment performed as well as it was designed to but didn't protect employees well enough. Second, they would go home and wash their hair and create the same problem at home."

To help reduce eye injuries and increase worker comfort and productivity, Ward decided to switch to a 3M air respirator system with a general purpose helmet. "Since we began using these supplied air respirator systems in April 1997, we've had no eye injuries. We're able to provide our employees with Grade D breathing air and at the same time provide a cooling effect, because these units have a Vortex unit to cool the filtered air before it flows over the head and face. So in the summer, if it's 90F (32C) outside with high humidity, it could easily be more than 100F (38C) in the sort area. So by switching to these systems, we've given workers the benefit of cool filtered air flowing down over their face and breathing zone."

A small number of Ward employees wear GVP-Series powered air purifying respirator (PAPR) systems fitted with an ammonia cartridge and high-efficiency particulate filter to protect them from gas and vapor contaminants as well as dust. "We require PAPR systems for use during baghouse changes, because workers are exposed to ammonia as well as dust," Johnson said. "We give each worker his own personal protective equipment. We stock all the parts here onsite. If some of the hoods need major repairs, we send them back for replacement parts and major maintenance. The day-to-day repairs we complete on our own. Workers are expected to keep their own equipment clean."