Regulatory Landscape for TCE in 

Federal Air Programs

Margaret Sheppard

Stratospheric Protection Division

Office of Air and Radiation

July 29, 2014 1

U.S. Environmental Protection Agency
Overview

• Major federal regulations under the Clean Air Act 

affecting TCE and its alternatives

• How air regulatory requirements affect cleaner 

selection

• Classes of available alternatives

• EPA’s Significant New Alternatives Policy (SNAP) 

program

• SNAP review of alternatives

• Recent solvent reviews

8/4/2014 U.S. Environmental Protection Agency 2
Three Air Programs Affect Solvent 

Choice Heavily

SNAP, ozone 

layer protection

Hazardous air 

pollutants (HAPs)

Ground-level ozone and volatile 

organic compounds (VOC)

8/4/2014 U.S. Environmental Protection Agency 3
Impact of Air Regulations on Cleaners

• Is the cleaner an ozone-depleting substance (ODS) 

to be phased out of production?

• Is the cleaning method or chemical on SNAP’s lists of 

acceptable alternatives?

– URL: http://www.epa.gov/ozone/snap/solvents/index.htm

– SNAP must review before entry into U.S. market

• Is chemical one of 187 HAPs under CAA?

– HAPs are regulated by industrial category

• Is chemical a VOC under 40 CFR 51.100(s)?

– Regulated VOC may be subject to state limits 

– Some chemicals are exempted because of negligible 

impacts on ground-level ozone—less regulated

July 29, 2014 U.S. Environmental Protection Agency 4
Impact of Air Regulations on TCE

• TCE is not an ODS

• SNAP lists TCE as acceptable for degreasing 

and aerosols

– SNAP categories do not directly address manual 

cleaning

• TCE is a listed HAP

– Use in degreasers subject to Halogenated Solvent 

Cleaning National Emission Standard for 

Hazardous Air Pollutants (NESHAP)

• TCE is a VOC under 40 CFR 51.100(s)

July 29, 2014 U.S. Environmental Protection Agency 5
Classes of Solvent Alternatives

TCE

PERC

methylene

chloride

isopropyl

alcohol

acetone

methyl

ethyl 

ketone

n-propyl bromide ?

 

HFC-4310mee HFE-7100

hexane heptane mineral

spirits

d-limonene

cyclohexane

trans-dichloroethylene

M ethyl chloroform

C FC -113

H C FC s

C hlorobrom om ethane

H FC s &

H FEs

A queous

cleaning

O xygenated 

solvents

H ydrocarbons,

T erpenes

Brom inated 

solvents

"N o-clean" 

technology

Sem iaqueous 

cleaning

C hlorinated

solvents
SNAP Program

• The SNAP Program is part of U.S. response to Montreal 

Protocol on Ozone-Depleting Substances that Deplete the 

Ozone Layer

• Section 612 of Clean Air Act directs EPA to evaluate and list 

substitutes for ozone depleting substances (ODS) that reduce 

overall risk to human health and the environment

• Covers 8 industrial sectors that used ODS historically

– Includes cleaning solvents and aerosols

• Substitutes include:

– Alternative chemicals (e.g., trans-dichloroethylene)

– Alternative technologies (e.g., aqueous cleaners)

– Product replacement (e.g., no-clean)

July 29, 2014 U.S. Environmental Protection Agency 7
SNAP Reviews of 

Alternatives

8

Criteria:

• Ozone Depletion Potential

• Global Warming Potential

• Local Air Quality

• Ecosystem Effects

• Flammability

• Toxicity

• Occupational & Consumer 

Health/Safety

Framework:

• Relative risk compared to other 

available or potentially available 

options

• Sector-focused

• Not necessary to be risk-free

• Rely on menu of options

– Promotes certainty and stability

– Encourages continuing innovation

• Consider existing rules, 

standards
Recent SNAP Solvent Reviews

• Listed as acceptable:

– Trans-1-chloro-3,3,3-

trifluoroprop-1-ene 

(cleaning, aerosols)

– Perfluoro-n-butyl 

iodide (cleaning)

– HFE-347pcf2 

(cleaning, aerosols)

• Solvents under review

– HFO

– CFO

– HFC

• New chemicals also 

reviewed by New 

Chemicals Program

July 29, 2014 U.S. Environmental Protection Agency 9