Environmental Sciences Seminar Abstract
Preliminary study of propyl bromide exposure among New Jersey dry cleaners as a result of a pending ban on perchloroethylene
Many states are considering, and some states have actively pursued, banning the use of perchloroethylene (PERC) in dry cleaning establishments. Proposed legislation has lead many dry cleaners to consider the use of products that contain greater than 90 percent n-propyl bromide (n-PB; also called 1-bromopropane or 1-BP). Very little information is known about toxicity and exposure to n-propyl bromide. Some n-PB containing products are marketed as nonhazardous and "green" or "organic." This has resulted in some users perceiving the solvent as nontoxic, and has resulted in at least one significant poisoning incident in NJ. In addition, many dry cleaning operators may not realize that the machine settings must be changed when converting from PERC to n-PB containing products, which may result in overheating and significant leaks in the dry cleaning equipment.
We conducted a preliminary investigation of the potential exposures to n-PB and isopropyl bromide (iso-PB; also called 2-bromopropane or 2-BP) among dry cleaners in New Jersey who have converted their machines from PERC to these new solvent products. Personal breathing zone and area samples were collected using the National Institute for Occupational Safety and Health (NIOSH) sampling and analytical method 1025, with a slight modification to gas chromatography conditions to facilitate better separation of n-PB from iso-PB. During our preliminary investigation, exposures to n-PB among workers in 2 out of 3 shops were measured that were greater than the American Conference of Governmental Industrial Hygienists (ACGIH) Threshold Limit Value (TLV) for n-PB. The highest exposure measured among a dry cleaning machine operator was 54 ppm as an 8-hour time weighted average, which is over five times than the ACGIH TLV of 10 ppm.
Our investigation also found that the work tasks most likely to result in the highest short-term exposures included the introduction of solvent to the machine, maintenance of the machine, unloading and lying out cleaned clothes, and interrupting the wash cycle of the machine. In addition, leaks within the machine contributed to exposure and may have resulted from normal machine wear over time, ineffective maintenance, and from the incompatibility of n-PB with gasket materials.
This study demonstrated that some "green" or "organic" alternative solvents in the dry cleaning industry intended to replace PERC may result in significant exposures above acceptable guidelines among workers. One dry cleaning worker reported serious adverse health effects resulting in an emergency room visit. Careful consideration and study of potential exposures and health effects among workers using new chemicals or new processes must precede any regulatory attempt to facilitate substitution for environmental purposes. This goal is made more challenging because of the jurisdictional separation of occupational safety and health agencies (e.g. OSHA) from environmental agencies (e.g. EPA).
Last updated: 04/15/2011