martes, 24 de febrero de 2015

CDC - NIOSH Science Blog – Occupational Exposures to New Drycleaning Solvents

CDC - NIOSH Science Blog – Occupational Exposures to New Drycleaning Solvents

Occupational Exposures to New Drycleaning Solvents

Employee pressing shirts by using two pressing machines.
Employee pressing shirts by using two pressing machines in series.


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.

Drycleaning Solvents

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;
  • butylal;
  • 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 occur through skin contact, we also took surface patch samples on two employees to see if they were getting these solvents on their hands during the machine cleaning process despite wearing gloves. We found solvents on their hands that may have resulted from reusing gloves or not selecting the proper glove material.
We saw employees mixing the butylal-based solvent with a fabric pretreatment and spraying the spot treatment mixture without personal protective equipment (such as gloves and eye protection). We also saw employees cleaning the waste material from the drycleaning machines without adequate personal protective equipment.
We provided recommendations for the shop owners and employees to help reduce their exposures to the drycleaning solvents and other chemicals. The recommendations involved work practice changes, improved housekeeping, equipment maintenance, and the proper selection and use of personal protective equipment. We also recommended employees brush and not spray fabric spot treatments, and wear eye and skin protection when cleaning the waste material from drycleaning machines. These recommendations were consistent with those resulting from our control banding assessment for butylal. See the reports below for complete prevention guidelines.
These evaluations are one step towards understanding the risks involved with alternative drycleaning solvents. Further research is needed to investigate the long term health effects of butylal. Independent evaluation of the toxicological properties of these alternative drycleaning solvents is needed.
For more information, see NIOSH Health Hazard Evaluations:

Help Wanted

We would like to hear from you.  In the comment section below, please  let us know:
  • What other new drycleaning solvents are being used to replace PERC?
  • Are airborne or skin exposures to new dry cleaning agents being measured in your workplace?
  • Are employees experiencing any health concerns that you think may be associated with the use of new drycleaning solvents?
We would also like to conduct more Health Hazard Evaluations in drycleaning establishments that use alternatives to PERC. If you are interested, you can request an HHE at our website. We can also provide technical assistance on requests to states and other government organizations that may be interested in improving the health and safety climate in the drycleaning industry.

Diana Ceballos, PhD, MS, CIH  is an Industrial Hygienist in the NIOSH Hazard Evaluations and Technical Assistance Branch in the Division of Surveillance, Hazard Evaluations and Field Studies.
Stephen Whittaker, PhD is with the Local Hazardous Waste Management Program in King County, Washington.
Eun Gyung Lee, PhD, CIH is an Industrial Hygienist in the Exposure Assessment Branch, Health Effects Laboratory Division, National Institute for Occupational Safety and Health.


*LHWMPExternal Web Site Icon is a coalition of local governments with the mission to protect and enhance public health and environmental quality in King County, Washington by reducing the threat posed by the production, use, storage and disposal of hazardous materials

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