Questions and Answers on Alternative Aerosols
This fact sheet provides an overview of regulations governing production, use and replacement of three ozone-depleting solvents, CFC-113, methyl chloroform (1,1,1-trichloroethane, TCA or 1,1,1), and HCFC-141b (1,1-dichloro-1-fluoroethane), under Title VI of the Clean Air Act. This fact sheet also provides information on how to find substitutes. If you have questions beyond those in this fact sheet, or would like paper copies of the lists, please call the Stratospheric Ozone Protection Hotline toll-free at 1 (800) 296-1996.
Questions and Answers about EPA's SNAP Program and the Use of Ozone Depleting Substances and their Substitutes in the Aerosols Sector
- What does "SNAP" stand for and what is involved in SNAP program reviews?
- Where can I find information on which substitutes have been listed as acceptable or unacceptable under SNAP?
- I want to get SNAP approval for a compound or a process used as an aerosol propellant or as an aerosol solvent. What should I do?
- Which solvent uses are subject to SNAP review and requirements?
- What is covered in the aerosol sector?
- How do the SNAP requirements for aerosols interact with the non-essential product ban on most aerosol uses of ozone depleters?
- Which substitutes for CFC-113, TCA or HCFC-141b have already been listed as acceptable under the SNAP program?
- What’s going on with the SNAP review of nPB?
A. SNAP review process
What does "SNAP" stand for and
what is involved in SNAP program reviews?
SNAP is EPA's Significant New Alternatives Policy program. The SNAP program implements Section 612 of the Clean Air Act. Under SNAP, EPA evaluates substitutes that companies propose to use as replacements for ozone-depleting substances like CFC-113, TCA, and HCFC-141b, in order to determine that the substitutes won't cause greater damage overall to human health or the environment than either the ozone depleters they are replacing or than other available substitutes. EPA generally reviews four key items when evaluating each proposed substitute:
- ozone-depleting potential,
- global-warming potential,
- toxicity, and
Based on this evaluation, EPA then decides whether unrestricted use of a substitute should be allowed, certain limits need to be placed on use, or use should be prohibited altogether.
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Where can I find information on which substitutes have been listed as acceptable or unacceptable under SNAP?
EPA published its first set of SNAP decisions on March 18, 1994 in the Federal Register (59 FR 13044). Since then, EPA has issued numerous updates. You can view the lists at www.epa.gov/ozone/snap/lists/.
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I want to get SNAP approval for a compound or a
process used as an aerosol propellant or as an aerosol
solvent. What should I do?
- You should first determine if the specific
application you have in mind falls within the scope of
the industrial sectors that are subject to SNAP. Your
proposal may involve a compound that does not substitute
for an ozone-depleter, or an application where ozone
depleters have played only a minor role. In these cases,
SNAP may not apply.
- Next, if you think that SNAP applies, you should
check the lists of substitutes under SNAP for the
appropriate sector. If your substitute is already on an
existing list for acceptable,
acceptable-with-restrictions, or unacceptable
substitutes, EPA does not require further review. Please
be aware that in the aerosol sector, EPA does not certify
individual companies' products. Instead, the
acceptability decisions are for specific compounds (e.g.,
trichloroethylene), for classes of substitute compounds
(e.g., oxygenated organic solvents), or for alternative
technologies (e.g., pump sprays).
- If your substitute is not on a list or if you are not
sure if SNAP applies, you should call the SNAP solvents
sector analyst at 202-343-9210 to determine whether your
product is covered by a broad category or has otherwise
been addressed by the SNAP program.
- If you and the analyst together decide that your
product is new and has not been reviewed, you must submit
it for EPA review using the SNAP submission form. You can
get the form by calling the hotline or viewing
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- You should first determine if the specific application you have in mind falls within the scope of the industrial sectors that are subject to SNAP. Your proposal may involve a compound that does not substitute for an ozone-depleter, or an application where ozone depleters have played only a minor role. In these cases, SNAP may not apply.
B. Scope of SNAP; Applicability of the Nonessential Products Ban to Aerosol Solvents
Which solvent uses are subject to
SNAP review and requirements?
EPA currently only reviews substitutes for CFC-113, TCA and HCFC-141b in three industrial sectors:
- non-aerosol solvent cleaning,
- aerosols (aerosol solvents), and
- carrier solvents used in adhesives, coatings and
inks, because it was in these sectors that use of CFC-113
and TCA were most widespread. EPA chose not to subject to
SNAP review industrial sectors that historically used
CFC-113, TCA and HCFC-141b on a more limited basis, such
as hydraulic system testing.
What is covered in the aerosol
The aerosol sector includes aerosol solvents and aerosol propellants. An aerosol is a liquid or solid that is suspended in the air in tiny particles or droplets once it is released from its container. In this sector, unlike the adhesives or non-aerosol solvents sectors, there are no uses exempted from SNAP review and requirements. However, only a limited number of aerosol applications are covered under the SNAP program because of the non-essential product ban on most uses of ozone depleting substances in aerosols.
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How do the SNAP requirements for aerosols interact
with the non-essential product ban on most aerosol uses of
Aerosol uses are subject not only to the SNAP requirements under section 612 of the Clean Air Act, but also to section 610 of the Act, which prohibits the sale, distribution and marketing--not the manufacture or use--of nonessential products that are made with ozone-depleting CFCs or HCFCs. These products, which include aerosol products and products that are contained in pressurized dispensers, are considered nonessential unless EPA specifically exempts them because alternatives do not exist or because available alternatives pose flammability and/or worker safety concerns. Examples of exempted products that may contain CFCs or HCFCs include:
- spinnerette lubricant/cleaning sprays used in the
production of synthetic fibers, which contain ozone
depleters as solvents and/or propellants;
- mold release agents used in the production of plastic
and elastomeric materials, which contain ozone depleters
- lubricants, coatings or cleaning fluids for
electrical or electronic equipment that contain ozone
depleters as solvents. Note that cleaning fluids for
electronic and photographic equipment are exempt for
commercial sale/distribution only, and the seller must
verify that the purchaser represents a commercial entity
and post a sign regarding the restriction;
- lubricants, coatings or cleaning fluids used for
aircraft maintenance that contain ozone depleters as
- medical devices that are listed in regulations of the
Food and Drug Administration at 21 CFR 2.125(e);
- document preservation sprays that contain ozone
depleters as solvents and/or propellants, but if they
contain ozone depleters as propellants, they may only be
used on thick books, books with coated or dense paper,
and tightly bound documents; and
- red pepper bear repellent sprays containing CFC-113 as a solvent.
The ban on any aerosol product or pressurized dispenser containing an ozone-depleter took effect January 1, 1994.
EPA has proposed eliminating current exemptions for gauze bandage adhesives and adhesive removers, topical anesthetic and vapocoolant products, lubricants for pharmaceutical tablet manufacture, containers of CFCs used as halogen ion sources in plasma etching, and red pepper bear repellent sprays containing CFC-113 as a solvent. EPA is still developing a final rule.
- spinnerette lubricant/cleaning sprays used in the production of synthetic fibers, which contain ozone depleters as solvents and/or propellants;
C. SNAP Status of Different Substitutes
Which substitutes have already
been listed as acceptable under the SNAP program?
Aerosol solvents listed as acceptable substitutes for CFC-113 and TCA, including:
- Oxygenated organic solvents such as esters, ethers, alcohols, etc.
- Chlorinated solvents (trichloroethylene, perchloroethylene, methylene chloride)
- Hydrofluoroether (HFE) 7100 and 7200
- Monochlorotoluenes and benzotrifluorides, subject to a 50 ppm workplace standard for monochlorotoluenes and a 100 ppm standard for benzotrifluoride
- HFC-4310mee, subject to a 200 ppm time-weighted average workplace exposure standard and 400 ppm workplace exposure ceiling
- Perfluorocarbons (PFCs) and perfluoropolyethers (PFPEs), although they are only acceptable for high-performance, precision-engineered applications in which reasonable efforts have been made to ascertain that other alternatives are not technically feasible due to performance or safety requirements
- C5-C20 Petroleum hydrocarbons
Solvents that have been listed as unacceptable substitutes for CFC-113 and TCA are:
- chlorobromomethane (CBM).
Aerosol propellants listed as acceptable substitutes for CFC-11, HCFC-22 and HCFC-142b are:
- light hydrocarbons (C3 to C6),
- dimethyl ether,
- HFC-227e, and
- compressed gases.
Alternative technologies that take the place of aerosol propellants are also acceptable substitutes, such as pumps, mechanical pressure dispensers, or non-spray dispensers.
Solvents that have been listed as unacceptable substitutes for CFC-11, HCFC-22 and HCFC-142b are:
- CBM and sulfur hexafluoride (SF6).
To ensure that you receive the most recent and comprehensive information, you should always check www.epa.gov/ozone/snap/lists/index.html#aerosol.
What’s going on with the SNAP review of
EPA has received petitions to add n-propyl bromide (nPB) to the list of
acceptable alternatives for the CFC-113, TCA and HCFC-141b in the
solvent sector for metal, precision, and electronics cleaning, as well
as in aerosol and adhesive applications.
EPA issued a proposed rule on June 3, 2003 . EPA is proposing to list n-propyl bromide (nPB) as an acceptable substitute for ozone-depleting substances (ODSs), subject to use conditions, in the solvent cleaning sector and aerosol solvents and adhesive end uses. While we find that nPB has a short atmospheric lifetime and low ozone depletion potential when emitted from locations in the continental U.S., the Agency cautions that significant use of nPB closer to the equator poses significant risks to the stratospheric ozone layer. Further, if workplace exposure to nPB is poorly controlled, it may increase health risks to workers. In the interim, until the Occupational Safety and Health Administration (OSHA) develops a mandatory workplace exposure limit under the Occupational Safety and Health Act, the Agency recommends that users of nPB adhere to an acceptable exposure limit of 25 parts per million (ppm) over an eight-hour time-weighted average.
EPA is proposing to list nPB as an acceptable substitute for chlorofluorocarbon (CFC)-113, hydrochlorofluorocarbon (HCFC)-141b, and methyl chloroform when used in aerosol solvent and adhesive end uses, subject to the condition that nPB used in these end uses not contain more than 0.05% isopropyl bromide by weight before adding stabilizers or other chemicals. We are also proposing to list nPB as an acceptable substitute for CFC-113 and methyl chloroform in general metals cleaning, electronics cleaning, and precision cleaning, subject to the condition that nPB used in these end uses not contain more than 0.05% isopropyl bromide by weight before adding stabilizers or other chemicals.
The public comment period on this proposal is from June 3, 2003 through August 4, 2003. The proposed rule gives instructions on how to submit your comments.
After considering the public comments, EPA will prepare a final rule in consultation with other parts of the government. The timing of the final rule will depend on the number and complexity of the issues raised in public comments. It usually takes EPA a year or more to finalize a rule after issuing a proposal.
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