Occupational exposures to new drycleaning solvents
By Diana Ceballos, PhD, MS, CIH; Stephen Whittaker, PhD; and Eun Gyung Lee, PhD, CIH
There are about 36,000 commercial drycleaning shops in the United States. Most are owner-operated small businesses with fewer than 10 employees. In addition, some drycleaning shops may be owned and staffed by individuals with limited English language skills and/or may be marginally profitable– factors that may create additional barriers for the owner-operator to maintain a safe and healthy workplace.
Environmental regulatory requirements and an increased awareness of the potential occupational hazards from using the drycleaning chemical perchloroethylene (PERC) have resulted in some drycleaners switching to alternative chemicals. Some of the PERC alternatives are promoted as safe and environmentally friendly, although their effects on human health and the environment are not well characterized. Some of the alternative drycleaning agents include:
- 1-bromopropane; (see blog 1-Bromopropane)
- high-flashpoint hydrocarbons;
- liquid silicone;
- dipropylene glycol t-butyl ether; and
- glycol ether cleaning liquid with liquid carbon dioxide.
Additionally, professional wet washing using water and detergents has also been used along with or to replace solvent-based drycleaning [EPA 2015].
Evaluating employees exposures to new drycleaning solvents
In 2012, investigators from the National Institute for Occupational Safety and Health (NIOSH) began working with the Local Hazardous Waste Management Program in King County, Washington (LHWMP)* to learn about occupational exposures to two alternative solvents. We performed four Health Hazard Evaluations at drycleaners that used either a high-flashpoint hydrocarbon mixture or butylal.
We collected personal and area air samples for the drycleaning solvents, as well as for formaldehyde and butanol, which are potential hydrolysis byproducts of butylal. We learned that the highest air concentrations of the drycleaning solvents were during loading and unloading of the machines and when pressing fabrics. Concentrations of the high-flashpoint hydrocarbon mixture and butanol in air were well below occupational exposure limits. However, there are no occupational exposure limits for butylal, and the long-term human health effects of butylal are unknown. We used control banding tools to assist in developing control recommendations for this solvent. When measuring for the other byproduct of butylal, formaldehyde, we did not find measurable levels or found very low concentrations in the air. The shop owners added a manufacturer recommended neutralizer to the drycleaning machine using butylal that helps prevent hydrolysis of the solvent and release of formaldehyde and butanol.
Because exposure to these drycleaning solvents can...Click here to read the rest of the blog post.