Dry Cleaning Proposed and Promulgated Rules: National Perchloroethylene Air Emission Standards

Dry Cleaning Proposed and Promulgated Rules: National Perchloroethylene Air Emission Standards


These maximum achievable control technology (MACT) standards will reduce emissions of Perchloroethylene (PCE) from new and existing dry cleaning facilities in the industrial and commercial sectors of the dry cleaning industry. Coin operated dry cleaning machines are exempt from the standards.

The final rule (see 40 CFR Part 63 Subpart M ) will reduce PCE emissions by an estimated 5,700 tons per year and will result in a net cost savings.

By the fifteenth year, the final rule will reduce PCE emissions from co- residential sources by an additional 317 tons/year. Cancer risks from all co- residential sources will be eliminated by the fifteenth year.



EPA has announced the first 10 chemicals it will evaluate for potential risks to human health and the environment under TSCA reform. One of the first ten chemicals to be evaluated is tetrachloroethylene, also known as perchloroethylene or perc.

Federal Register Citations:

  • 73 FR 39871
  • 73 FR 17292
  • 73 FR 17252
  • 71 FR 55280
  • 71 FR 42724
  • 71 FR 6030
  • 70 FR 75884
  • 61 FR 49263
  • 61 FR 27785
  • 61 FR 19887
  • 60 FR 64002
  • 58 FR 66287
  • 58 FR 49354
  • 56 FR 64382

Related Rules

Control Technique Guidance: Control of Volatile Organic Compound Emissions from Large Petroleum Dry Cleaners

Petroleum Dry Cleaners: New Source Performance Standards (NSPS)

Rule History

07/11/2008 - Withdrawn Direct Final Rule & Final Action on Proposed Rule

04/01/2008 - Proposed Rule & Direct Final Rule

09/21/2006 - Federal Register Correction

07/27/2006 - Final Rule

02/06/2006 - Proposed Rule & Extension of Comment Period

12/21/2005 - Proposed Rule (National Perchloroethylene Air Emission Standards for Dry Cleaning)

06/23/2003 -
Final Rule; Clarification to Existing National Emissions Standards for Hazardous Air Pollutants Delegations' Provisions

12/14/1999 -
Final Rule; Amendments

09/19/1996 - Final Amendments to the Rule

06/03/1996 - Final Rule

05/03/1996 - Proposed Amendments to the Rule

12/13/1995 - Proposed Rule; Amendment

12/20/1993 - Final Rule

09/22/1993 - Final Rule

12/09/1991 - Proposed Rule & Notice of Public Hearing (National Emissions Standards for Hazardous Air Pollutants for Source Categories: Perchloroethylene Dry Cleaning Facilities)

09/22/93 58 FR 49354 Final Rule Final Rule: Perchloroethylene Dry Cleaning Facilities
10/19/93 58 FR 3900 Notice Notice of Public Meeting
12/20/93 58 FR 66287 Amendments Amendments to final rule
07/22/94 59 FR 37494 Notice Notice of Availability of Comparison Study of Conventional Dry Cleaning and Alternative Processes
12/13/95 60 FR 64002 Proposed rule Proposed Amendments to NESHAP's for Chromium Electroplaters, Ethylene Oxide Commercial Sterilizers, Perchloroethylene Dry Cleaners and Secondary Lead Smelters. Except in the case of secondary lead smelters, proposes to exempt non-major sources from Title V Operating Permits
06/03/96 61 FR 27785 Final Rule National Emission Standards for Hazardous Air Pollutants for: Chromium Emissions From Hard and Decorative Chromium Electroplating and Chromium Anodizing Tanks; Ethylene Oxide Commercial Sterilization and Fumigation Operations; Perchloroethylene Dry Cleaning Facilities; and Secondary Lead Smelting/Title V exemptions and deferals
10/17/95 60 FR 53728 Proposed Rule Proposed Rule giving 112(l) delegation to the State of California for Dry Cleaners
05/21/96 61 FR 25397 Final Rule Final Rule giving 112(l) delegation to the State of California for Dry Cleaners
06/11/96 61 FR 29485 Notice National Emission Standards for Hazardous Air Pollutants for Source Categories: Perchloroethylene Dry Cleaning Facilities; Notice of Availability of Guidance
09/19/96 61 FR 49263 Amendments National Emission Standards for Hazardous Air Pollutants for Source Categories: Perchloroethylene Dry Cleaning Facilities; Amendments
08/18/99 64 FR 45115 Proposed Amendment Title V Operating Permit Defferals for Area Sources: National Emission Standards for Chromium Emissions from Hard and Decorative Chromium Electroplating and Chromium Anodizing Tanks; Ethylene Oxide Commercial Sterilization and Fumigations Operations; Perchloroethylene Dry Cleaning Facilities; Halogenated Solvent Cleaning Machines; and Secondary Lead Smelting
12/14/99 64 FR 69637 Final Rule Title V Operating Permit Defferals for Area Sources: National Emission Standards for Chromium Emissions from Hard and Decorative Chromium Electroplating and Chromium Anodizing Tanks; Ethylene Oxide Commercial Sterilization and Fumigations Operations; Perchloroethylene Dry Cleaning Facilities; Halogenated Solvent Cleaning Machines; and Secondary Lead Smelting

NOTES: All files above are not from Government Printing Office (GPO) , those published 1994 and later will be replaced with GPO published files in near future

Closely Related Rules, Policies or Program Guidance

02/07/96 61 FR 49263 Final Air Quality; Revision to Definition of Volatile Organic Compounds--Exclusion of Perchloroethylene

Technical Information

Background Information Document (BID)/Response to comments

11/14/05 Background Information Document (PDF, 170 pp, 1.4MB)

FACT Sheets

11/14/05 Health Effects Fact Sheet: Tetrachloroethylene (Perchloroethylene)
10/93 Technical Fact Sheet - Dry Cleaner Final Rule with amendments

Risk Assessement Information

11/14/05 Perchloroethylene Dry Cleaners Refined Human Health Risk Characterization (PDF, 69 pp, 2.5MB)

Implementation Information

Implementation Memoranda and Documents

05/20/96 Guidance Concerning Implementation scanned image
10/94 General Recommended Operating and Maintenance Practices for Dry cleaning Equipment (Only for use when Manufacturers' Information is Unavailable (EPA-4531R-94-073) OCR scanned

Source Identification and Location Information

Outreach and Training Materials

Colorado, APCD Dry Cleaning Inspection Guidance and Check List
Colorado A Simple Guide to Air Quality Rules for Perc Dry Cleaners
Nebraska, Lincoln-Lancaster County Health Department Dry Cleaning Facts
Nebraska, Lincoln-Lancaster County Health Department Dry Cleaning Facts
Nebraska, Lincoln-Lancaster County Health Department Dry Cleaner P2
Washington State, Department of Ecology Dry Cleaner Reference Manual
Evaluating Exposures to Toxic Air Pollutants: A Citizen's Guide

Permitting Information

01/17/96 Incorporation of Startup, Shutdown, and Malfunction Plans into Source's Title V Permits OCR scanned

Compliance and Enforcement Information

02/04/98 Dry Cleaner Air Toxics Standard -Compliance Alert
08/04/97 Dry Cleaner MACT -Compliance Alert scanned image
09/20/96 Carbon Adsorbers used in Azotropic Control Systems for Compliance scanned image


  • Danish Information
  • Dry Wash Information
  • Cold Clean Information
    NOTE: Some links on this page are pointers to other hosts and locations in the Internet. This information is provided as a service; however the U.S. Environmental Protection Agency does not endorse, approve or otherwise support these sites.

NIOSH Safety and Health Topic:


The commercial drycleaning industry in the United States consists of approximately 36,000 shops. Most of these shops are small businesses with fewer than 10 employees. Approximately 85% of drycleaning shops in the U.S. use perchloroethylene as their primary solvent.

NIOSH researchers have conducted numerous studies of the commercial drycleaning industry. Some of these studies have evaluated a variety of health and safety hazards; however the greatest emphasis has been placed on worker exposure to perchloroethylene. NIOSH research in this industry has involved exposure assessment, engineering control evaluations, and epidemiologic studies. Information concerning these studies is outlined below.


Drycleaning Image

On This Page...


NIOSH Publications on Drycleaning

Published Articles

Worker Notification Program

Links to Other Drycleaning Sites


NIOSHTIC-2 search results on Drycleaning
NIOSHTIC-2 logo is a searchable bibliographic database of occupational safety and health publications, documents, grant reports, and journal articles supported in whole or in part by NIOSH.

NIOSH Publications on Drycleaning

Control of Ergonomic Hazards in Commercial Drycleaning
DHHS (NIOSH) Publication No. 97-160 (1998)
this document in PDF PDF 68 KB (4 pages)
Musculoskeletal disorders are caused by repetitive motions, awkward postures, excessive reaching, and precision gripping. In the drycleaning industry, ergonomic risks occur during garment transfer, pressing, and bagging. These activities, combined with a high work rate and frequency, may cause physical discomfort and musculoskeletal problems for workers. Disorders can include damage to tendons, muscles, nerves, and ligaments of the hand, wrist, arm, shoulder, neck, and back.

Control of Fire Hazards in Commercial Drycleaning Shops Using Petroleum-Based Solvents
DHHS (NIOSH) Publication No. 97-159 (1998)
this document in PDF PDF 90 KB (3 pages)
Drycleaning shops contain all elements necessary for uncontrolled fires: fuels, ignition sources, and oxygen. Potential combustible materials include furniture, garments, lint, and portions of the building. The greatest risk of fire and explosion exists if the drycleaning shop uses a petroleum-based solvent in drycleaning machines. Approximately 10% of drycleaning shops in the United States use these highly flammable solvents. Ignition can be triggered by a burning or smoldering cigarette, heated equipment such as a press, a frictional spark inside the solvent reclaimer cage, or even static electricity within the reclaimer.

Control of Spotting Chemical Hazards In Commercial Drycleaning
DHHS (NIOSH) Publication No. 97-158 (1998)
this document in PDF PDF 68 KB (3 pages)
Many hazardous chemicals are commonly used in drycleaning shops to remove garment stains. Workers performing stain removal may be exposed to these toxic chemicals through skin absorption, eye contact, or inhalation of vapors. The primary hazard is dermatitis from chronic or acute exposure. Dilute hydrofluoric acid, found in some products that remove rust stains, may cause severe chemical burns with deep tissue destruction that may not be evident until several hours after prolonged contact.

Control of Exposure to Perchloroethylene in Commercial Drycleaning (Ventilation)
DHHS (NIOSH) Publication No. 97-157 (1997)
this document in PDF PDF 103 KB (4 pages)
To reduce exposure to drycleaning solvents, a comprehensive control approach should be followed involving engineering measures, work practices, and personal protection. Engineering measures are the preferred and most effective means of control and should generally considered first. One of the potentially least expensive engineering control options for reducing worker exposures to PERC involves effective ventilation.

Control of Exposure to Perchloroethylene in Commercial Drycleaning (Machine Design)
DHHS (NIOSH) Publication No. 97-156 (1998)
this document in PDF PDF 446 KB (4 pages)
Esta P�gina en Espa�ol En Español
Drycleaning machines have evolved over time to better protect worker safety and health and the environment. Drycleaning machines encompass five "generations" which are currently used in the United States. Modern drycleaning machines can dramatically reduce exposures, save money in solvent costs, and permit easier compliance with safety, health, and environmental regulations.

Control of Exposure to Perchloroethylene in Commercial Drycleaning (Substitution)
DHHS (NIOSH) Publication No. 97-155 (1998)
this document in PDF PDF 72 KB (4 pages)
Esta P�gina en Espa�ol En Español
If a substance is hazardous to health or to the environment, sound industrial hygiene practice dictates that a less hazardous material or process be considered as a substitute. In drycleaning there are a number of potential alternatives to using perchloroethylene.

Control of Exposure to Perchloroethylene in Commercial Drycleaning
DHHS (NIOSH) Publication No. 97-154 (1998)
this document in PDF PDF 112 KB (3 pages)
Esta P�gina en Espa�ol En Español
To reduce exposure to drycleaning solvents, a comprehensive control approach should be followed involving engineering measures, work practices, and personal protection. Engineering measures are the preferred and most effective means of control and should generally considered first.

Control of Health and Safety Hazards in Commercial Drycleaners: Chemical Exposures, Fire Hazards, and Ergonomic Risk Factors
DHHS (NIOSH) Publication No. 97-150 (1998)
This report investigates control methods and technologies used in the drycleaning industry for reducing occupational exposures to tetrachloroethylene, also known as "perchloroethylene" (PERC). It also examines drycleaning machines that use petroleum-based solvents. It addresses methods for controlling exposures to spotting chemicals, fire, and ergonomic hazards in commercial drycleaning shops. Data were gathered during ten field surveys at drycleaning shops across the U.S. and through a World Health Organization (WHO) fellowship in Europe.

Worker Notification Program

Through the NIOSH Worker Notification Program , NIOSH notifies workers and other stakeholders about the findings of past research studies related to a wide variety of exposures. The links below present archival materials sent to participants in studies related to drycleaning.

Published Articles

An Evaluation of Retrofit Engineering Control Interventions to Reduce Perchloroethylene Exposures in Commercial Drycleaning Shops
(abstract--bibliographic information only)
(Applied Occupational Environmental Hygiene (In Press))
Real-time monitoring was used to evaluate the ability of engineering control devices retrofitted on two existing dry-cleaning machines to reduce worker exposures to perchloroethylene. In one dry-cleaning shop, a refrigerated condenser was installed on a machine that had a water-cooled condenser to reduce the air temperature, improve vapor recovery, and lower exposures. In a second shop, a carbon adsorber was retrofitted on a machine to adsorb residual perchloroethylene not collected by the existing refrigerated condenser to improve vapor recovery and reduce exposures.

Mortality in dry-cleaning workers: an update
( full text with permission )
(American Journal of Industrial Medicine (2001; vol. 39, pp. 121-132))
this document in PDF PDF only 86 KB (32 pages)
Background: A cohort of 1,708 dry-cleaning workers identified from union records, was exposed to perchloroethylene (PCE), a known animal carcinogen and probable human carcinogen, for at least one year before 1960. Many workers also had exposure to Stoddard solvent, a petroleum-based dry-cleaning solvent.

Concerns of the Dry-Cleaning Industry: A Qualitative Investigation of Labor and Management
(full text with permission)
(American Journal of Industrial Medicine (1999; vol. 35, pp. 112-123))
this document in PDF PDF only 61 KB (38 pages)
Occupational scientists agree there are hazards associated with dry-cleaning, but do dry-cleaning owners and workers concur? Knowledge of owners' and workers' perceptions can help guide intervention efforts to reduce worker exposure. To better understand these issues, a qualitative study was conducted using focus group methodology and constant comparative analysis. Two owner and four worker focus groups were held. Findings suggest that overall, health and safety issues were not of great concern. Owners were primarily concerned with the economic impact of regulations. Workers did express some anxiety about solvent exposure and burns, but most felt that these hazards were "just part of the job". Also, other than the installation of air-conditioning in the shops and the provision of health benefits, workers could not think of ways health and safety on the job could be improved.

Evaluation and Control of Perchloroethylene Exposures During Dry Cleaning
(full text with permission)
(Applied Occupational Environmental Hygiene (1996; vol. 11 (2) pp. 125-32))
this document in PDF PDF only 1 MB (8 pages)
A study was conducted at a large, commercial dry cleaner to evaluate the control of worker exposure to perchloroethylene (PERC) and provide recommendations to reduce exposure. This shop used a dry-to-dry machine that had a refrigerated condenser, which operated during the dry cycle, as the primary vapor recovery device. A small fan that was ducted to a carbon canister was the secondary vapor recovery device.

World Health Organization Fellowship for U.S. Citizens: A Compendium of Participant Reports 1990-1995. "Lessons From Europe: Reducing Occupational Exposure and Environmental Emissions to Perchloroethylene in Commercial Dry Cleaning". US Department of Health and Human Services, Health Resources and Services Administration, International Health Affairs
(abstract--bibliographic information only)
(Applied Occupational Environmental Hygiene)
Researchers from the National Institute for Occupational Safety and Health (NIOSH) received a World Health Organization (WHO) fellowship to study methods and controls to reduce occupational exposure to and environmental emissions of perchloroethylene (PERC) in Europe. This study involved gathering information concerning dry-cleaning regulations, equipment, exposure levels, work practices, and alternatives to PERC. Much of the recent research and development into new technologies for reducing emissions and exposure to perchloroethylene has been conducted in Germany and Italy. Governmental regulatory and nonregulatory organizations, research institutions, manufacturers of equipment and chemicals, and dry-cleaning shops were visited during this study.

Links to Other Drycleaning Sites

EPA-Garment and Textile Care Program
External Link: http://www.epa.gov/dfe/projects/garment/index.htm
Describes the Garment and Textile Care Partnership program sponsored by EPA's Design for the Environment Program.

OSHA - Dry Cleaning
External Link: http://www.osha-slc.gov/SLTC/drycleaning/
OSHA safety and health topic about dry cleaning containing many links to resources grouped under categories such as recognition, evaluation, control, compliance, training and more...

Neighborhood Cleaners Association
External Link: http://www.nca-i.com/
information for both the consumer and professional cleaners and suppliers, including an FAQ, consumer reports, more...

International Fabricare Institute
External Link: http://www.ifi.org/
Includes descriptions of the drycleaning process and other drycleaning-related topics.

Union of Needletrades, Industrial and Textile Employees
External Link: http://www.unite-svti.org/
A textile union website.

Toxics Use Reduction Institute
External Link: http://www.turi.org/
The Massachusetts Toxics Use Reduction Institute (TURI) was created to promote reduction in the use of toxic chemicals and the generation of toxic by-products in industry and commerce in the state of Massachusetts.

Center for Neighborhood Technology
External Link: http://cnt.org/
A Chicago based organization that develops methods and invents tools to help create livable urban communities.

Guidance and information for
Occupational Safety and Health Administration
Directorate of Standards and Guidance

Download PDF (499 KB)
Executive Summary

This document has been prepared by the Occupational Safety and Health Administration (OSHA) to help dry cleaning establishments reduce employee exposures to perchloroethylene (also known as perc, tetrachloroethylene, C 2 Cl 4 or Cl 2 C=CCl 2 ). The dry cleaning industry has improved the control of perchloroethylene in recent years, and modern dry cleaning equipment involves much lower exposures than older style equipment. However, there is still a need to reduce employee exposure to the chemical to reduce any possible health effects that could result from long-term exposure to the chemical. Many dry cleaning employers have found that equipment design, preventive maintenance, control of leaks in equipment, proper ventilation, and good work practices can reduce perc exposure to workers, reduce costs by recovering perc for reuse, help create a cleaner environment, and help comply with federal and state environmental regulations. The document is organized into the following sections:

  1. Introduction
  2. Health Hazards
  3. Perc Exposure
  4. Current Regulations and Recommendations
  5. Machine Design and Maintenance
  6. Ventilation
  7. PPE, Work Practices and Training
  8. Perc Air Monitoring
  9. Assistance
  10. Case Studies
Appendix A. Recommended Maintenance Schedule for Dry Cleaning Machines
Appendix B. International Chemical Safety Card for Tetrachloroethylene

This guidance document is not a standard or regulation, and it creates no new legal obligations. The Bulletin is advisory in nature, informational in content, and is intended to assist employers in providing a safe and healthful workplace. The Occupational Safety and Health Act requires employers to comply with hazard-specific safety and health standards. In addition, pursuant to Section 5(a)(1), the General Duty Clause of the Act, employers must provide their employees with a workplace free from recognized hazards likely to cause death or serious physical harm. Employers can be cited for violating the General Duty Clause if there is a recognized hazard and they do not take reasonable steps to prevent or abate the hazard. However, failure to implement these recommendations is not, in itself, a violation of the General Duty Clause. Citations can only be based on standards, regulations, and the General Duty Clause.


I. Introduction

Perchloroethylene ("perc") has long been recognized as an effective dry cleaning solvent and today it is by far the most commonly used solvent in dry cleaning shops. However, as a volatile organic solvent, perc may pose serious health hazards if exposure is not properly controlled. Dry cleaning workers who routinely breathe excessive amounts of the solvent vapor or spill perc on their skin are at risk of developing health problems.

Special precautions are recommended to avoid health risks from perc exposure. The purpose of this guidance is to provide practical and effective ways for dry cleaning operators to reduce worker exposure to perc. The guidance emphasizes reducing perc exposure through a combination of using modern equipment and preventive maintenance, control of leaks in dry cleaning equipment, proper ventilation, and good work practices.

II. Health Hazards

During dry cleaning, perc primarily enters the body from inhalation of the vapors, potentially resulting in the following health hazards:
  • Dizziness, drowsiness, and loss of coordination;
  • Mild loss of memory, visual perception, and reaction time after several years of exposure; or
  • Redness and blistering of the skin after prolonged dermal contact.
There is some evidence of an association between perc and increased risk of certain cancers in dry cleaning workers exposed for many years. The National Institute for Occupational Safety and Health (NIOSH) has designated perc a "potential occupational carcinogen." The National Toxicology Program has designated it as "reasonably anticipated to be a human carcinogen." The International Agency for Research on Cancer (IARC) has designated perc as a "probable human carcinogen."

The possibility of these health hazards can be minimized by reducing worker exposures to perc vapor and by avoiding skin contact with perc.

III. Perc Exposure

Primary Sources of Perc Exposure

Dry cleaning employees may be exposed to perc while performing both routine tasks and machine maintenance. Activities that result in elevated exposure include the following:
  • Loading dirty clothes into the machine (when perc-contaminated air is displaced and forced out of the machine);
  • Removing clothes, especially thick items, before the drying cycle is finished;
  • For transfer machines, transferring solvent-laden clothes into the dryer;
  • Cleaning lint and button traps;
  • Raking out the still (distillation unit residue);
  • Changing the solvent filter;
  • Maintenance of water separator; and
  • Handling and storage of hazardous waste.
Machine Fugitive Emissions

Uncontrolled emissions, so-called "fugitive emissions," from dry cleaning machines can also expose workers to high levels of perc. These include:
  • Perc emissions not captured by vapor recovery and thus released when the loading door is opened or through the vent; and
  • Perc emissions from leaks in machines, hoses, valves, and ducts.
Secondary Sources of Perc Exposure

Other possible sources of perc exposure not directly associated with the dry cleaning equipment include:
  • Pressing freshly dry cleaned clothes;
  • Using a perc-based spotting agent; and
  • Using a perc-based waterproofing agent. (1)
IV. Current Regulations and Recommendations

OSHA has set mandatory permissible exposure limits (PELs) for perc, presented in Table 1. This table also lists perc exposure limits recommended by other safety and health organizations.

Table 1. Worker Exposure Limits
for Perchloroethylene (Tetrachloroethylene)
Organization 8-hour time- weighted average (TWA)
Other limits
Permissible Exposure Limit (PEL): 100 parts per million (ppm)
Ceiling: 200 ppm (for 5 mins. in any 3-hr. period), with a maximum peak of 300 ppm
Threshold Limit Value (TLV):
25 ppm
Short-term exposure limit (STEL):
100 ppm (as a 15-min. TWA)
Potential Occupational Carcinogen; Minimize workplace exposure concentrations.

Other OSHA standards that may apply when workers are exposed to perc include: Hazard Communication (29 CFR 1910.1200); General requirements for personal protective equipment (29 CFR 1910.132); and Respiratory Protection (29 CFR 1910.134).

In addition to these worker exposure limits, dry cleaning facilities must comply with EPA regulations controlling the release of perc into the environment - air, land, and water. EPA has developed regulations that affect many aspects of dry cleaning operations, including machine operation and maintenance, building design and ventilation, work practices, as well as perc storage and disposal. There are also EPA requirements on air monitoring for perc release, record keeping, and perc use reporting. (For further information on EPA regulations, see Plain English Guide for Perc Cleaners , EPA, 2003.)

V. Machine Design and Maintenance

Dry cleaning technology has evolved substantially over the decades. The newer machine designs (dry-to-dry, closed looped) greatly reduce the amount of perc vapor released into the air inside the shop as well as outdoors, resulting in cost savings since more perc is recovered for reuse, as well as safer working conditions and a cleaner environment.

The oldest type of dry cleaning machines - transfer machines - can expose workers to high amounts of perc, particularly during transfer of solvent-laden clothing from washer to dryer. Newer equipment ( dry-to-dry machines) reduce worker exposure by eliminating this transfer step (clothes enter and exit the machine dry).

The first dry-to-dry equipment, dry-to-dry vented , exhausts residual solvent vapors either directly outside or first through a perc vapor recovery system. The present designs, dry-to-dry closed loop machines, recirculate perc rather than release it outdoors. The latest technology incorporates a secondary vapor recovery system on the dry-to-dry closed loop machines that most effectively minimizes perc usage, environmental releases, and worker exposure to perc. Figure 1, below, illustrates the perc exposure levels of machine operators associated with the various dry cleaning machines.

Figure 1

Replacing equipment that wears out with modern equipment can reduce exposures. Also, routine machine maintenance combined with detection and timely repair of identified leaks can be extremely effective in controlling airborne levels of perc vapor. (See the Case Studies described in Section X.) The EPA estimates that as much as 25 percent of solvent emissions can be attributed to leaks. In addition to creating unsafe airborne levels of perc, leaks are wasteful and costly. Routine machine maintenance needs to be performed to ensure optimal operation of all components. Appropriate personal protective equipment (PPE) needs to be worn during maintenance activities to ensure protection from perc hazards. (See Section VII for more information on PPE.)

Recommended machine maintenance activities include the following:
  • Clean lint and button traps regularly to prevent clogging of condensers and fans.
  • Rake out still daily. (Consider installing a pump that allows residue to be pumped directly to a safety can.)
  • Change all filters as necessary.
  • Desorb carbon adsorber before saturation point.
  • Adjust refrigerated condensers to ensure proper temperature of drying air.
  • Maintain and repair exhaust fans.
A recommended schedule of maintenance activities is provided at the back of this booklet.


To control perc leaks from dry cleaning equipment:
  • Perform daily checks for leaks in door gaskets, valves, hoses, pumps, tubing, and piping connections. Look for liquid pools and droplets on or around equipment. Unusual solvent odor may indicate a vapor leak (do not rely only on the sense of smell for detecting leaks).
  • Replace gaskets before they become hard, cracked, or worn.
  • Use a direct-reading air-monitoring device (see Section VIII) to detect vapor leaks in piping, exhaust ductwork, and associated components.
  • Use perc-resistant seals and fittings recommended by the manufacturer of the machine.
  • Repair leaks immediately.

VI. Ventilation

Adequate ventilation is essential for controlling perc levels within the dry cleaning shop. General ventilation , provided by equipment such as overhead fans, is useful for reducing heat and humidity and diluting perc levels. Such ventilation can be designed to move the perc vapors away from workers and customers while continuously supplying clean, fresh air to the dry cleaning area.

Local exhaust ventilation (LEV) captures perc vapor at the source of the release, removing the vapor before it enters the air inside the shop. Well-designed LEV may be provided where perc exposure is highest, for example, at the loading door. Newer dry cleaning equipment has built-in LEV designed to prevent escape of vapors during machine loading and unloading. For machines without built-in LEV, an external ventilation hood outside the machine door can be installed to control vapors when the door is open. (A study describing this method of control is summarized in Case Study #5 in Section X.)

Detailed information regarding desirable configurations for general ventilation and LEV as well as recommendations on exhaust fan placement and capacity can be found in pamphlets by the International Fabricare Institute (IFI) (1989) (2) and NIOSH (1998) (3) .

VII. PPE, Work Practices, and Training

Personal protective equipment (PPE)
- including aprons, gloves, goggles, and respirators approved for use with organic chemicals - is used to help workers avoid perc exposure. Workers must wear respirators equipped with filters or cartridges specifically designed for organic vapors when elevated perc exposures are anticipated (29 CFR 1919.134). Tasks where elevated exposure may occur include machine maintenance, filter changes, waterproofing operations, and loading/unloading machines (depending on the equipment in use). Workers using transfer machines may also need to wear chemical-resistant aprons. Spotters can wear goggles, chemical-resistant aprons, and gloves. Spill cleanup workers always need to wear respirators and gloves.

Work Practices - Good work practices can greatly minimize worker exposure to perc vapors. For example, peak exposure levels can be reduced by several hundred parts per million simply by proper positioning of the worker's head and body during transfer operations. Other important work practices to reduce perc exposures are listed below.

Work Practice Tips for Dry cleaning Operators
  • Do not load the machine past its capacity.
  • Do not open the machine door when the cycle is running.
  • Keep the machine door CLOSED as much as possible.
  • Do not "shortcut" the drying cycle by removing garments from the machine before the cycle is finished.
  • Keep your head and face turned away from the machine door and clothes when removing solvent-laden clothes from the washer.
  • Do not transfer perc to machines by hand or with open buckets. Use a closed piping system that connects directly to the machine drum.
  • WAIT until the machine and solvent are cold before performing maintenance.
  • Use spotting agents sparingly.
  • Use perc-free spotting agents.
  • Clean up perc spills immediately. (The shop should have in place a plan for safely responding to perc spills.)
  • Store containers of perc and perc wastes in tightly sealed containers.
  • Position your hand away from the door when opening a transfer machine.

Training - Dry cleaning employees need training on how to protect themselves from the hazards of perc (OSHA Hazard Communication standard, 29 CFR 1910.1200). Employees should be trained in proper work practices for all of their expected tasks - operating and maintaining machines, spotting, waterproofing, housekeeping, and perc transfer and storage.

Workers must be trained on the health hazards and symptoms associated with perc exposure. Workers should become familiar with Material Safety Data Sheets (MSDS) and container labels for perc (OSHA Hazard Communication standard, 29 CFR 1910.1200). The International Chemical Safety Card for perc can be found in Appendix B of this publication to help with this training.

In addition, workers should be familiar with the location and proper use of eyewash stations as well as procedures for responding to first aid emergencies, such as eye splashes and skin contamination. OSHA requires employers to train their employees about hazards and methods to prevent exposure to chemicals used in the workplace (OSHA Hazard Communication standard, 29 CFR 1910.1200). Workers must also be trained on the proper use of respirators (Respiratory Protection standard, 29 CFR 1910.134).

VIII. Perc Air Monitoring A variety of devices and instruments are available to measure perc levels in the air. Reasons for performing air monitoring include:
  • To determine the perc exposure levels of individual employees;
  • To identify sources of leaks in equipment; and
  • To measure perc levels before and after modifications to equipment or procedures.
The type of air monitoring method used depends on the purpose of the sampling, the technical abilities of the person, who conducts the testing, and the cost of the equipment. To determine the perc exposures of individual workers, a sample can be obtained by clipping a monitoring device to the worker's collar either with a battery-powered pump or a simple monitoring badge.

The samples are then sent to a qualified laboratory to analyze the perc concentration. The results can be compared with the OSHA PEL and other recommended exposure limits for perc (listed in Table 1).

For detecting equipment leaks and other emissions, portable, direct-reading devices provide either a visual/audible indication of a leak or an instantaneous measurement of the perc vapor concentration at the source of the emission. These instruments vary in terms of cost, accuracy, and ease of use.

Two relatively inexpensive, easy to use leak- detection devices are:
  • Small, hand-held refrigerant leak detectors that indicate a perc leak by a visual and audible signal; and
  • Colorimetric detector tubes (used with small, hand-operated pumps) that change color depending on the perc vapor concentration.
More sophisticated types of direct reading devices include infrared analyzers and photoionization detectors that provide accurate measurements of perc concentration, but are more expensive and require technical expertise to operate.

IX. Assistance

OSHA has a free consultation service for small and medium-sized businesses with hazardous operations. The service is confidential and offers the expertise of qualified occupational safety and health professionals to employers who request advice and assistance. OSHA consultation is available in all 50 States, the District of Columbia, Guam, Puerto Rico, the Northern Mariana Islands and the Virgin Islands. Information on OSHA consultation services can be found at: www.osha.gov/dcsp/smallbusiness/consult.html .

For assistance with perc monitoring, consult your perc supplier's product stewardship program or a professional dry cleaning association, such as the International Fabricare Institute. If you need the technical expertise of an industrial hygienist, the American Industrial Hygiene Association (AIHA) offers a listing of qualified consultants at: http://www.aiha.org/ConsultantsConsumers/html/consultantsclient.asp .

X. Case Studies

Dry cleaning shop owners have numerous options available for reducing the perc exposures of their employees. The case studies below describe the effectiveness of measures such as installing relatively low-cost machine retrofits, installing LEV, and performing routine machine maintenance and leak detection.

Case Study #1: Emission Control Retrofit - Carbon Adsorber

Installing a new carbon adsorber on a dry cleaning machine reduced the perc exposures of operators by 92 percent, according to a NIOSH study. The 60-pound closed-loop carbon adsorber was installed to remove residual perc not collected by the existing refrigerated condenser on the closed-loop, dry-to-dry machine. The retrofit cost less than $5,000.

Before the retrofit, the average perc exposure of operators during the one-minute machine loading and unloading process was 353 ppm. After the carbon adsorber was installed, the average exposure was 29 ppm, a reduction of approximately 92 percent.

Case Study #2: Emission Control Retrofit - Refrigerated Condenser

A NIOSH study found that perc exposures of dry cleaning machine operators were reduced by 60 percent after a refrigerated condenser was installed on a dry cleaning machine.

A 5-ton cooling capacity refrigerated condenser was installed on a vented, dry-to-dry machine in place of its original water-cooled condenser and single-pass carbon adsorber. The retrofit cost less than $5,000. Before the installation of the refrigerated condenser, the average perc exposure of machine operators during the one-minute machine loading and unloading phase was 1,139 ppm. After the retrofit, the average exposure was 456 ppm, a reduction of about 60 percent. NIOSH cautioned that only dry cleaning machines in good repair with few leaks should be considered for retrofitting. Although this technology significantly reduced perc exposure in this case, it does not eliminate it and additional controls would be needed to achieve further reductions.

Case Study #3: Gasket Leak - Detection and Repair

Repairing a leaking gasket on a dry cleaning machine resulted in a full-shift perc exposure reduction of 22 ppm, according to a NIOSH study of retrofit emission controls (described further in Case Study #2). The gasket at the rear of the machine being retrofitted with a new refrigerated condenser sprung a leak during the installation. Before the retrofit, TWA perc concentrations averaged 47 ppm. Measurements taken after the leak was fixed resulted in an average perc exposure of 25 ppm.

Case Study #4: Distillation Unit Leak - Detection and Repair

During the LEV evaluation (described in Case Study #5), NIOSH noted that the full-shift perc exposures of machine operators were up to four times higher on the day when the distillation unit was operating (about 20 ppm vs. 5 ppm when the unit was turned off). These elevated readings led to the identification and repair of a leak in the distillation system. If perc monitoring had not been conducted, the leak might not have been detected. This study underscores the importance of routine perc air monitoring to identify and repair equipment leaks.

Case Study #5: Local Exhaust Ventilation

A NIOSH study showed that installation of a simple, inexpensive LEV system was effective in reducing average full-shift TWA perc exposures of machine operators by 37 percent.

Before the LEV installation, the average full-shift perc exposure was 4.7 ppm. The 12-year-old dry cleaning machine was a dry-to-dry, closed-loop design with a 50-pound capacity. The LEV system, including fabrication, installation, and electric wiring, was installed for $2,560. The LEV was positioned directly above the dry cleaning machine door and exhausted air from in front of the door only when the door was opened. The average perc exposure was reduced by about 37 percent, to 3.0 ppm, after the LEV installation.

Appendix A. Recommended Maintenance Schedule for Dry Cleaning Machines

Daily Maintenance Tasks
  • Clean button trap strainer and lint bag.
  • Dispose of contaminated water from the water separator.
  • Desorb the carbon adsorber.
  • Rake out the still of the distillation unit (or weekly as needed).
Weekly Maintenance Tasks*
  • Check door seatings and gaskets of machine cylinder for liquid and vapor leaks.
  • Check the button trap for lid leaks.
  • Launder the lint bag.
  • Check seals and gaskets of the refrigerated condenser's diverter valve, distillation unit, filters, filter housings, and muck cooker for liquid and vapor leaks.
  • Rake out the still of the distillation unit (or daily as needed).
  • Clean the separator tank of the water separator and perform leak checks.
  • Measure the exhaust temperature of the refrigerated condenser.
  • Measure perc in the exhaust system.
  • Perform leak checks on hose and pipe connections, fittings, couplings, and valves.
Monthly Maintenance Tasks
  • Check the exhaust damper (vented machines) for liquid and vapor leaks.
  • Check for lint buildup on the heating and condensing coils and refrigerated condenser coils.
  • Check for leaks in the ductwork of the lint trap and carbon adsorber.
  • Check for lint buildup on the temperature probe of the lint trap.
  • Clean the vent of the water separator.
Semi-Annual Maintenance Tasks
  • Clean the muck cooker's steam and condensation coils.
Annual Maintenance Tasks
  • Clean the heating/condensing and refrigerated condenser coils.
  • Clean and change filters according to the manufacturer's schedule.
*Note: The EPA requires weekly leak detection and repair for large dry cleaners and bimonthly leak detection and repair for small dry cleaners. The type of machine (dry-to-dry or transfer) and the amount of perc purchased each year determines whether a dry cleaner is large or small. Refer to the Plain English Guide for Perc Dry Cleaners for details ( http://www.epa.gov/opptintr/dfe/pubs/garment/perc/ ).

Appendix B. International Chemical Safety Card for Tetrachloroethylene

The following International Chemical Safety Card (ICSC) for tetrachloroethylene was published in 2000. The ICSCs project is an undertaking of the International Programme on Chemical Safety (IPCS). The project is being developed in cooperation between the IPCS and the Commission of the European Communities. The IPCS is a joint activity of three cooperating international organizations: the United Nations Environment Programme (UNEP), the International Labour Office (ILO) and the World Health Organization (WHO). The main objective of the IPCS is to carry out and disseminate evaluations of the hazards posed by chemicals to human health and the environment.

ICSC cards summarize essential health and safety information on chemicals for their use at the shop floor level by workers and employers. Cards are available for over 1,300 chemicals, and they are provided in several languages, including English, Korean, Spanish, Russian, French, German, Japanese and Chinese.

To access the most recent ICSC card for perc, to locate the perc card in another language, or to find the card for another chemical, access the NIOSH Internet site at: http://www.cdc.gov/niosh/ipcsneng/neng0076.html .

International Chemical Safety Cards
ILO UNEP EU Flag NIOSH Harmful Stow away from foodstuffs Poison Marine Pollutant
C 2 Cl 4 / Cl 2 C=CCl 2
Molecular mass: 165.8 ICSC # 0076
CAS # 127-18-4
UN # 1897
EC # 602-028-00-4
FIRE Not combustible. Gives off irritating or toxic fumes (or gases) in a fire. In case of fire in the surroundings: all extinguishing agents allowed.
-INHALATION Dizziness. Drowsiness. Headache. Nausea. Weakness. Unconsciousness. Ventilation, local exhaust, or breathing protection. Fresh air, rest. Artificial respiration if indicated. Refer for medical attention.
-SKIN Dry skin. Redness. Protective gloves. Protective clothing. Remove contaminated clothes. Rinse and then wash skin with water and soap.
-EYES Redness. Pain. Safety goggles, face shield. First rinse with plenty of water for several minutes (remove contact lenses if easily possible), then take to a doctor.
-INGESTION Abdominal pain (further see Inhalation). Do not eat, drink, or smoke during work. Rinse mouth. Do NOT induce vomiting. Give plenty of water to drink. Rest.
Ventilation. Collect leaking and spilled liquid in sealable containers as far as possible. Absorb remaining liquid in sand or inert absorbent and remove to safe place. Do NOT let this chemical enter the environment. (Extra personal protection: filter respirator for organic gases and vapours). Separated from metals ( see Chemical Dangers ), food and feedstuffs . Keep in the dark. Ventilation along the floor. Do not transport with food and feedstuffs.
Marine pollutant.
Xn symbol
N symbol
R: 40-51/53
S: (2-)23-36/37-61
UN Hazard Class: 6.1
UN Packing Group: III
ICSC: 0076 Prepared in the context of cooperation between the International Programme on Chemical Safety & the Commission of the European Communities (C) IPCS CEC 2001. No modifications to the International version have been made except to add the OSHA PELs, NIOSH RELs and NIOSH IDLH values.














The vapour is heavier than air.

On contact with hot surfaces or flames this substance decomposes forming toxic and corrosive fumes (hydrogen chloride, phosgene, chlorine). The substance decomposes slowly on contact with moisture producing trichloroacetic acid and hydrochloric acid. Reacts with metals such as aluminium, lithium, barium, beryllium.

TLV: 25 ppm; RET(STEL): 100 ppm; (ACGIH 1999).
OSHA PEL: TWA 100 ppm C 200 ppm 300 ppm (5-minute maximum peak in any 3-hours)
NIOSH REL: Ca Minimize workplace exposure concentrations. See Appendix A
NIOSH IDLH: Potential occupational carcinogen 150 ppm

The substance can be absorbed into the body by inhalation and by ingestion.

A harmful contamination of the air will be reached rather slowly on evaporation of this substance at 20�C.

The substance irritates the eyes, the skin and the respiratory tract. Swallowing the liquid may cause aspiration into the lungs with the risk of chemical pneumonitis. The substance may cause effects on the central nervous system. Exposure at high levels may result in unconsciousness.

Repeated or prolonged contact with skin may cause dermatitis. The substance may have effects on the liver and kidneys. This substance is probably carcinogenic to humans.
Boiling point: 121�C
Melting point: -22�C
Relative density (water = 1): 1.6
Solubility in water, g/100 ml at 20�C: 0.015
Vapour pressure, kPa at 20�C: 1.9
Relative vapour density (air = 1): 5.8
Relative density of the vapour/air-mixture at 20�C (air = 1): 1.09
Octanol/water partition coefficient as log Pow: 2.9
Environmental HazardThe substance is toxic to aquatic organisms. The substance may cause long-term effects in the aquatic environment.
Depending on the degree of exposure, periodic medical examination is indicated. The odour warning when the exposure limit value is exceeded is insufficient. Do NOT use in the vicinity of a fire or a hot surface, or during welding. An added stabilizer or inhibitor can influence the toxicological properties of this substance, consult an expert.
Transport Emergency Card: TEC (R)-722
NFPA Code: H2; F0; R0;
IMPORTANT LEGAL NOTICE: Neither NIOSH, the CEC or the IPCS nor any person acting on behalf of NIOSH, the CEC or the IPCS is responsible for the use which might be made of this information. This card contains the collective views of the IPCS Peer Review Committee and may not reflect in all cases all the detailed requirements included in national legislation on the subject. The user should verify compliance of the cards with the relevant legislation in the country of use. The only modifications made to produce the U.S. version is inclusion of the OSHA PELs, NIOSH RELs and NIOSH IDLH values.

Footnote 1 Use of perc-based spotting or waterproofing agents is not current practice in the dry cleaning industry. However, these operations are addressed in this document for those few dry cleaning establishments that may continue to use these products. (Back to text)

Footnote 2 IFI. 1989. Reducing Vapor Exposure: OSHA compliance. International Fabricare Institute. Vol. 13, No. # 5. (Back to text)

Footnote 3 NIOSH. 1998. Control of Exposure to Perchloroethylene in Commercial Drycleaning. NIOSH Hazard Controls. DHHS (NIOSH) Publication No. 97-154. http://www.cdc.gov/niosh/hc16.html (Back to text)

Ways to save money AND help the environment:

Eat healthier AND save money: Instant Pot Duo Crisp 11-in-1 Air Fryer and Electric Pressure Cooker Combo with Multicooker Lids that Fries, Steams, Slow Cooks, Sautés, Dehydrates

Save water AND money with this showerhead adapter, it lets the water flow until the water is hot, then shuts off water flow until you restart it, ShowerStart TSV Hot Water Standby Adapter

Protect your health with these:

Mattress Dust mite-Bedbug protector, 100% Waterproof, Hypoallergenic, Zippered

Handheld Allergen Vacuum Cleaner with UV Sanitizing and Heating for Allergies and Pet, Kills Mite, Virus, Molds, True HEPA with Powerful Suction removes Hair, Dander, Pollen, Dust,

Immune Support Supplement with Quercetin, Vitamin C, Zinc, Vitamin D3

GermGuardian Air Purifier with UV-C Light and HEPA 13 Filter, Removes 99.97% of Pollutants

5 Stage Air Purifier, Features Ultraviolet Light (UVC), H13 True Hepa, Carbon, PCO, Smart Wifi, Auto Mode, Quiet, Removes 99.97% of Particles, Smoke, Mold, Pet Dander, Dust, Odors

Interesting Reads:

THE PREPPER'S CANNING & PRESERVING BIBLE: [13 in 1] Your Path to Food Self-Sufficiency. Canning, Dehydrating, Fermenting, Pickling & More, Plus The Food Preservation Calendar for a Sustainable Pantry

The Backyard Homestead: Produce all the food you need on just a quarter acre! Paperback

The Citizens' Guide to Geologic Hazards: A Guide to Understanding Geologic Hazards Including Asbestos, Radon, Swelling Soils, Earthquakes, Volcanoes

The Uninhabitable Earth: Life After Warming

Book: The Sixth Extinction: An Unnatural History Paperback

See Echo Dot on Amazon