About SNAP Review

On this page:

• Guiding Principles
• Criteria for Evaluating Alternatives
• EPA’s Classifications of Decisions on Alternatives

Guiding Principles

The guiding principles of the SNAP program are:

• Evaluate substitutes within a comparative risk framework
• Do not require that substitutes be risk-free to be found acceptable
• Restrict only those substitutes that are significantly worse
• Evaluate risks by use
• Provide the regulated community with information as soon as possible
• Do not endorse products manufactured by specific companies
• Defer to other environmental regulations when warranted

Criteria for Evaluating Alternatives

EPA's decision on the acceptability of new substitutes proposed by manufacturers, formulators, or users is based primarily on the potential human health and environmental risks posed by the substitutes as compared other substitutes available for a particular end-use. EPA's evaluation of each substitute in an end-use is based on the following types of information and analyses:

• Atmospheric effects―The SNAP program considers the ODP and 100-year integrated GWP of compounds to assess atmospheric effects.
• Exposure assessments―Exposure assessments are used to estimate concentration levels of substitutes to which workers, consumers, the general population, and environmental receptors may be exposed over a determined period of time. These assessments are based on personal monitoring data or area sampling data if available. Exposure assessments may be conducted for many types of releases including:
  • Releases in the workplace and in homes
  • Releases to ambient air and surface water
  • Releases from the management of solid wastes
• Toxicity data―Toxicity data is used to assess the possible health and environmental effects for exposure to substitutes. The Occupational Safety and Health Administration (OSHA) or EPA approve wide health-based criteria that are available for a substitute such as:
  • Permissible exposure limits (PELs for occupational exposure)
  • Inhalation reference concentrations (RfCs for non-carcinogenic effects on the general population)
  • Cancer slope factors (for carcinogenic risk to members of the general population)

If OSHA has not issued a PEL for a compound, EPA also considers Workplace Environmental Exposure Limits (WEEL) set by the American Industrial Hygiene Association (AIHA), threshold limit values (TLV) set by the American Conference of Governmental Industrial Hygienists (ACGIH), or Recommended Exposure Limits (REL) set by the National Institutes of Occupational Safety and Health (NIOSH). If limits for occupational exposure or exposure to the general population are not already established, then EPA derives these values following the Agency's peer-reviewed guidelines. If a manufacturer provides a recommended exposure limit, EPA would review the information used in derivation and compare to its own exposure limit derivation. Exposure information is combined with this toxicity information to explore any basis for concern. Toxicity data is used with existing EPA guidelines to develop health-based criteria for interim use in these risk characterizations.

• Flammability―Flammability is examined as a safety concern for workers and consumers. EPA assesses flammability risk using data on:
  • Flash point and flammability limits (e.g., OSHA flammability/ combustibility classifications) o Data on testing of blends with flammable components
  • Test data on flammability in consumer applications conducted by independent laboratories o Information on flammability risk minimization techniques
• Other environmental impacts―The SNAP program also examines other potential environmental impacts such as ecotoxicity and local air quality impacts. A compound that is likely to be discharged to water may be evaluated for impacts on aquatic life. Some substitutes are volatile organic compounds (VOCs), which are chemicals that increase tropospheric air pollution by contributing to ground-level ozone formation. In addition, EPA notes whenever a potential substitute is considered a hazardous air pollutant or hazardous waste.

40 CFR 82.178 details the specific data to be submitted.

EPA’s Classifications of Decisions on Alternatives

How Do SNAP Listings Work?

EPA's classifications of decisions on alternative substitutes are the following:

• Acceptable substitutes are determined to reduce overall risk to human health and the environment compared to other substitutes for the particular end-use. These alternatives may be used without restriction in the specified end-uses.
• Acceptable subject to use conditions indicates that a substitute is acceptable only if used in a certain way. For example, substitutes in motor vehicle air conditioning systems are acceptable subject to a use condition that the substitute be used with unique equipment fittings on the system (for servicing) and on refrigerant containers.
• Acceptable subject to narrowed use limits indicates that a substitute may be used only within certain specialized applications within a sector and end-use, and may not be used for other applications within an end-use or sector. The Agency requires a user of a narrowed use substitute to demonstrate that no other acceptable substitutes are available for their specific application.
• Unacceptable alternatives are prohibited because the Administration has determined the use of the substitutes pose significantly higher human health and environmental risks than those risks from use of other available or potentially available substitutes.

Use conditions and narrowed use limits are both considered “use restrictions.” For example, in the aerosols and solvents sectors, EPA does not list 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., hot-melt adhesives). EPA publishes decisions made under the SNAP program in the Federal Register. All SNAP Rules and Notices are available online on the Regulations page.