As part of its Design for the Environment (DfE) program, EPA has issued a report assessing eight environmentally preferable alternatives to nonylphenol ethoxylates (NPE), a class of popular surfactants that at low concentrations are lethal to fish and other aquatic organisms.

The safer alternatives to NPE identified in the report are:

1. C9-11 alcohols, ethoxylated (6 EO)
2. C12-15 alcohols, ethoxylated (9EO)
3. Oxirane, methyl-, polymer with oxirane, mono(2-ethylhexyl ether); Ecosurf EH-9
4. D-Glucopyranose, oligomeric, decyl octyl glycosides
5. Benzenesulfonic acid, C10-13-alkyl derivs., sodium salt
6. Sodium lauryl sulfate
7. Polyoxy(1,2-ethanediyl), alpha-sulfo-omega-dodecyloxy-, sodium salt
8. Sorbitan monostearate

Surfactants are chemicals used in products to provide increased surface activity and reduce the surface tension of water, allowing easier spreading, wetting, and better mixing of liquids. NPEs are used in many detergents as well as other types of cleaners, degreasers, indoor pesticides cosmetics, oilfield chemicals, and paints and coatings. NPEs degrade to more toxic chemicals, including nonylphenol. EPA estimates U.S. and Canadian consumption of NPEs at between 300 and 400 million pounds per year.

Through DfE and other initiatives, EPA has worked with diverse stakeholder groups for years in reviewing the environmental effects of hundreds of surfactants and alternatives. The methodology used in the current assessment is based on this substantial effort, says EPA. To be acceptable as a DfE-labeled product, an alternative to NPE would have to have a passing hazard score across five categories:

• Persistence
• Degradates of concern
• Acute aquatic toxicity
• Chronic aquatic toxicity
• Aquatic toxicity of degradates

Chemicals did not have to achieve high scores in each category. For example, a chemical that ranked very high for aquatic toxicity could still be found acceptable if it ranked very low for persistence.

Chemical assessments in the report were based on data from seven sources:

1. Publicly available, measured (experimental) data obtained from a comprehensive literature review
2. Measured data from EPA OPPT confidential databases
3. SAR-based estimations from the EPA New Chemical Program’s Pollution Prevention (P2) Framework and Sustainable Futures predictive methods
4. Estimates from the EPA Chemical Categories document, which groups chemicals with shared chemical functionality and toxicological properties into categories based on EPA's experience evaluating chemicals under the New Chemicals Program
5. Professional judgment of EPA staff who identified experimental data on closely related analogs
6. Confidential studies submitted by chemical manufacturers
7. The CleanGredients® database

When experimental data were lacking, EPA says that predictive models and the expert judgment of scientists from EPA's New Chemical Program were used to assess physical/chemical properties, environmental fate, and aquatic toxicity endpoints.

EPA notes that the industrial/institutional laundry industry has pledged to eliminate use of NPE surfactants in all liquid detergents by December 31, 2013, and in all powder detergents by December 31, 2014.