Perchloroethylene (PCE)

Presented by: Elizabeth Bemis, Holly Kingsbury, Emily Steen, Daniel Vigil, Petra Wolford

What is Perc?

PerchloroethyleneTetrachloroethylene

PCE“Perc”

Cl2C=CCl2

PCE: PERC, Perchloroethylene

“A volatile organic compound (VOC)”

In 1985, worldwide production was about 1 million metric tons

(Rossberg 2006)

Widely used for dry cleaning and as a metal degreaser, in typewriter correction fluid, and shoe polish.

Small amounts are also retained by recently dry cleaned clothing

Where Else Can it be Found?

•It is used as a “building block” for creating other chemicals.•Some consumer products may contain perc as well.

But, What is It?

•A synthetic chemical that at room temperature is a nonflammable liquid.

•An organic solvent that easily dissolves organic material like oil and grease.

•It easily evaporates (volatile) and has a sharp and sweet odor, detectable in the air at a level of 1 ppm.

Occupational Exposure

PerchloroethyleneTetrachloroethylene

PCE“Perc”

Cl2C=CCl2

How does a worker get exposed?

• Most likely exposure from the air we breathe • Levels are usually several thousand times lower than what is found in dry

cleaning facilities, industrial operations, and waste sites.

• Exposure can also occur from contaminated groundwater, soil, food, and certain consumer products • Water repellants, spot removers, adhesives, and wood cleaners. • Perc may stay in the air for several months and eventually settle into the soil

and water because of precipitation

• For an average individual not living near businesses or waste sites that use or contain PCE, exposure is well below the maximum exposure limits provided by the EPA for workers.

• Individuals that work with PCE are at a greater risk for adverse health effects.• According to NIOSH more than 650,000 U.S. workers may be exposed.

Occupational Exposure:Dry Cleaning

• We already know PCE can contaminate the air through evaporation from liquid solvent, contaminated water, or contaminated soil

• Dry cleaners are a significant site of occupational exposure via inhalation: • Risks from excessive inhalation as well

as spilling PCE solvent on exposed skin• Loading dirty clothes into the machine

(displacement of pre-contaminated air)• Removing clothes before the drying

cycle is finished• Transferring solvent-laden clothes

into the dryer• Cleaning and maintaining machines • Possible: Pressing freshly dry-cleaned

clothes

Safe Exposure LimitsOrganization 8-hour time weighted

averageOther limits

OSHA (mandatory) PEL: 100 PPM Ceiling: 200 ppm for 5 min in a 3 hour period

ACGIH (voluntary) TLV: 25 ppm STEL: 100 ppm

NIOSH Minimize workplace exposure concentrations

85% of the more than 35,000 dry cleaners in the United States use PCE as a solvent in the dry cleaning process.

Health Risks with Exposure

PerchloroethyleneTetrachloroethylene

PCE“Perc”

Cl2C=CCl2

What Are The Risks Of Exposure?

Harm From Exposure: CancerEPA 2013: “likely to be carcinogenic to humans”

Human Epi Studies

•Occupational exposure

•Increased risk of Bladder cancer, Lymphoma and Multiple Myeloma

•Dose Response

Animal Studies

•Clear carcinogen

•Leukemia and liver cancer were caused in multiple studies

•Kidney, brain and testicular cancer also seen

Harm From Exposure: NeuroEPA 2013: “Neurotoxicity was supported by

considerable evidence...and at lower concentrations”

Human Epi Studies

•Occupational or Residential exposure

•Deficits in Visual Acuity and Memory, Cognitive Function, and Reaction Times

•Levels as low as 0.7ppm

Animal Studies

•Same effects seen

•Changes in the cerebellum, frontal cortex & hippocampus

•Brain DNA, RNA, protein and lipid composition altered

Harm From Exposure:What about me?

• Occupational exposure is in the range of 60ppm

• Apartments sharing a building with dry-cleaners ~0.7ppm

•

• Dry-cleaned clothes in a vehicle ranged from <0.1 to >3ppm

• Outdoor air near an industrial contamination site <0.001ppm

• PCE is highly concentrated in breast milk

How Can PCE Be Cleaned/Reduced?

PerchloroethyleneTetrachloroethylene

PCE“Perc”

Cl2C=CCl2

PCE and Surface Discharge

Underground Plumes in Colorado

• There are at least 86 underground plumes (from PERC) in Colorado!

• 350 Dry Cleaners are currently using PERC in Colorado alone. It is still legal to use.

Remediation Technologies

The first step is to find Potentially Responsible Parties (PRPs) and discover each PRP’s allocated portion (responsibility)

Plumes are massive, cover miles and involve numerous contributing sources.

Remediation is extremely expensive and involves years of litigation.

What Policies Are In Place?

PerchloroethyleneTetrachloroethylene

PCE“Perc”

Cl2C=CCl2

Conclusion

National and State regulations have helped in reducing harmful levels of PERC in the air.

Because of epidemiological studies we now know the harmful effects of PERC and can better protect workers and the public through remediation activities and air and water quality regulations.

Requirement of “no new PERC dry cleaning facilities” offers a promising end to the PERC dry cleaning story.

References• Agency for Toxic Substances and Disease Registry. (1997). "Toxicological Profile For Tetrachloroethylene". Atlanta, GA, p. 174.

Retrieved 2012-09-16. citing C&EN, 1994, Facts and Figures for the Chemical Industry, Chemical and Engineering News, July 4, 1994.• Agency for Toxic Substances and Disease Registry (1997). Public health statement: tetrachloroethylene. CAS#: 127-17-4. Available at:

http://www.atsdr.cdc.gov/ToxProfiles/tp18-c1-b.pdf. Accessed April 3, 2014.• Environmental Protection Agency (2011). Removal of “Perc’ Pollution Begins at Former Cleaners http://www.epa.

gov/region5/cleanup/sandies/pdf/sandies_fs_09212011.pdf• Environmental Protection Agency. (2012). Toxicological Review of Tetrachloroethylene (CAS No. 127-18-4).• Ferroni C, et.al. (1992). Neurobehavioral and neuroendocrine effects of occupational exposure to perchloroethylene,

Neurotoxicology, 13:243-247.• Gold, Laura S. et.al. (2011). The Relationship between Multiple Myeloma and Occupational Exposure to Six Chlorinated Solvents;

Occupational and Environmental Medicine, 68(6): 391-399.• Henshaw, S. (2013). Enviroforensics.com When Contaminated Groundwater Plumes Run Together, How is the Cost of Cleanup

Divided? Available at: http://www.enviroforensics.com/commingled-plumes-who-is-responsible-for-the-cleanup/ • National Center for Environmental Assessment, US Environmental Protection Agency. (2014). Human Health Effects of

Tetrachloroethylene: Key Findings and Scientific Issues. Available at: http://ehp.niehs.nih.gov/1307359/#tab2.• NIOSH. (1994b). NIOSH manual of analytical methods. Third edition. Second supplement. Cincinnati, OH: NIOSH, U.S. Department

of Health and Human Services, National Institute for Occupational Safety and Health, NIOSH method no. 1003.• Occupational Safety and Health Administration (2005). Reducing worker exposure to perchloroethylene (perc) in dry cleaning.

Available at: https://www.osha.gov/dsg/guidance/perc.html. Accessed April 3, 2014.• Rossberg, M., et al. (2006). “Chlorinated Hydrocarbons” in Ullmann’s Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim.

doi:10.1002/14356007.a06_233.pub2• Seidler, A., et. al. (2007). Solvent exposure and malignant lymphoma: a population-based case-control study in Germany; Journal of

Occupational Medicine and Toxicology, 2:2.• Stevens, Y., and Eisenmann, C. (1997). Toxicological Profile for Tetrachloroethylene. Retrieved from http://www.atsdr.cdc.

gov/toxprofiles/tp18.pdf.• Tetracholorethylene (2006) Concise International Chemical Assessment Document 68. Available at: http://www.who.

int/ipcs/publications/cicad/cicad68.pdf.