OSHA removes perc from reg calendae

OSHA has called a halt in its 13-year effort to establish lower standards for workplace exposure to perchloroethylene.

A brief announcement in OSHA’s semi-annual regulatory agenda published last month said the agency is withdrawing its plans to re-evaluate perc “at this time due to resource constraints and other priorities.”

The planned re-evaluation had been on the agenda since 1996 when OSHA put perc on a list of 20 chemicals to examine for possible revision of maximum workplace exposure levels.

Other than “resource constraints and other priorities,” there was no other explanation from OSHA for removing perc from the agenda now. However, Bob Wright, an OSHA public affairs officer noted that perc could be placed back on the agenda at some time in the future. A number of other items were removed from the regulatory agenda this fall for similar reasons.

For perc, the workplace exposure limits remain where they were in 1988 when OSHA made its first attempt at revising them. At that time, OSHA proposed dropping the 8-hour time weighted exposure from 100 parts per million (ppm) to 25 parts per million as part of a wholesale revision that involved several hundred other substances.

That action was overturned by the Eleventh Circuit Court of Appeals in July 1992 in a ruling that stated OSHA needed to show a scientific basis for setting new levels of each chemical. At the time, the International Fabricare Institute, which had joined the suit against OSHA, said that a level of 50 ppm would be sufficient to protect workers in perc plants. Labor groups, however, were also suing OSHA, arguing that the level should be even lower than 25 ppm.

After the court ruling, the previous 100 ppm level was reinstated. In 1996, OSHA again stated its intention to lower the perc exposure level, but despite fears among some in the industry that OSHA might reduce the level to below 10 ppm, little has taken place over the past five years.

OSHA heard from industry representatives at a meeting in 1996 on the issue. At that meeting, the Neighborhood Cleaners Association told OSHA that the 100 ppm level was too high but that a 50 ppm level would be realistic.

The following year, IFI announced that a revived exposure level for perc would be delayed at least until 1998, citing the complexities that OSHA faced in the rule-making process which required OSHA to perform four substantial legal analyses. OSHA first would need to identify that a risk exists, that the risk is substantial and that a new exposure limit would reduce that risk. OSHA also would need to show that the means to reduce the risk are “technically and economically feasible” for an industry.

Later that year, OSHA met with a number of parties interested in the issue, including, IFI, NCA, the Textile Care Allied Trades Association, the Fabricare Legislative and Regulatory Education organization, the Center for Emissions Control, Greenpeace and advocates of substitute technologies. At that time it was said that the process of setting a new PEL for perc could take one to two years to complete.

In 1998, OSHA announced that perc would not be among the first group of chemicals to get new exposure standards.

Although the possibility of new, lower exposure limits has lurked in the background over the past few years, there has been no further word from OSHA that it was ready to take action. Pat Williams, IFI’s government relations director, said OSHA officials met with IFI about a year ago to discuss possible future directions, but nothing had been heard from the agency on the issue since then.

Thus, for the foreseeable future, OSHA’s permissible exposure levels remain where they were in 1988. The time weighted exposure, which is the average as measured over an eight-hour day, is 100 ppm. The ceiling limit, which can’t be exceeded except for peak exposures, is 200 ppm; and the maximum peak exposure, which is the ceiling limit for an eight-hour shift, limited to five minutes in any three-hour period, is 300 ppm.

It should be noted that more stringent standards have been adopted by some states and that a 25 ppm limit has been advocated by both the American Conference of Governmental Industrial Hygienists (ACGIH). Dow’s product literature and MSDS for perc also advise a 25 ppm maximum exposure level.

Although OSHA has been unable to revise its exposure levels for perc, changes within the industry may have largely achieved the same results. Last year, Dow noted that average worker exposure from third, fourth, and fifth generation equipment is typically below 10 ppm. Exposure from first generation equipment averages about 37 ppm, however.

Cleaners can’t trust their noses to tell them when perc vapor levels are getting too high. For most people, the odor threshold is in the range of 40-50 ppm. For some with sensitive olfactory nerves, it can be as low as 5 ppm. But for people who are regularly exposed to the odor, the threshold is likely to be much higher.