“Every 15 years, the Environmental Protection Agency requires new exposure data to be generated, showing the typical worker exposure to biocides,” explained Philip R. Miller of Lubrizol Corp. in Spartanburg, S.C., which makes biocides and other metalworking fluid additives. “So ACC’s Antimicrobial Exposure Assessment Task Force wants to find metalworking facilities, small- to medium-size machine shops that do metal-removing operations such as grinding and cutting and drilling, to join our study.”

The shop’s metalworking fluid should contain or be routinely treated with an EPA-registered biocide or fungicide, Miller continued. Ideally, it would be a phenolic-type or BIT (1,2-Benzisothiazolin-3-one), since these compounds can be detected analytically at very low concentrations.

ACC will ask experienced machinists to let researchers collect exposure data while they go about their usual work. The volunteers will wear a full-body cotton suit (long underwear) plus socks, pants, shirt and shoes provided by the testers, and have an air sampler clipped to their lapel or waistband. The researchers will recover the clothes and air monitor at the end of the shift, and then measure the amount of biocides that the items may have absorbed.

ACC’s Shah, who is based in Arlington, Va., said EPA will use the exposure data to assess how to regulate biocides in the workplace. “It will help gain approvals for new biocides, and also may be used to reevaluate the limits for workplace exposures of existing biocides. In the absence of this data, EPA will use worst-case exposure in setting the limits,” he noted. “We hope to show that real-world exposure to biocides is actually much lower, so that requires us to develop this data.”

Shah described the perfect shop for the study as having at least 15 machines, staffed by at least three or four workers on the shop floor. “We hope to get at least three sites or shops to participate, and more would be better.”

The monitoring takes just one day, and the ACC testers will need access to the site for a few days before in order to prepare the participants for their role. More than one worker at each site is welcome to participate, Shah added.

Not only large sophisticated sites are invited to join, but also medium-size and mom-and-pop operations where biocides are on the scene. For its part, shop management needs to provide access to evaluate the facility, and to allow sampling of the metalworking fluid. A short meeting also is needed so researchers can recruit workers.

To sweeten the deal for management, the research team offers to conduct OSHA training on topics of the shop owner’s choice, Lubrizol’s Miller added. Afterward, ACC will share data on each shop’s mist level and worker exposure with the owner, who can relate the results to workers.

The study is structured under strict ethical standards, he emphasized, and worker participation is completely voluntary. The study is strictly observational — there is no intentional dosing of workers.

“We have good guidelines for the ethical conduct of the study,” Shah agreed. “Our concern right now is that we need the sites.”

As thanks for the individuals for their time, ACC is offering $100 to each participating machinist. The need is urgent enough, said Miller, “that ACC also will pay $500 to the person who proposes a site for the test, if it results in the test actually being performed at that site.”

ACC’s task force has been trying to recruit participants for two years, Shah said, “but our members make the biocides, not the metalworking fluids. They sell to the metalworking fluid formulators, not to the end-users. So we don’t really know the exact sites where the chemicals go in industry.” He hopes the cash incentives will bring volunteers to ACC’s door.

To learn more, e-mail Has Shah at Has_shah@americanchemistry.com or Phil Miller at phil.miller@lubrizol.com.