Safer Choice Criteria for Surfactants
Surfactants in cleaning products are distinguished by their:
- rate of biodegradation,
- degradation products, and
- level of aquatic toxicity.
The Safer Choice Criteria for Surfactants combine these hazard characteristics, and require that surfactants with higher aquatic toxicity demonstrate a faster rate of biodegradation without degradation to products of concern. Surfactants that meet the Safer Choice Criteria are acceptable for use in a Safer Choice product; surfactants in products which typically bypass sewage treatment must meet the Criteria for Environmental Fate & Toxicity for Chemicals in Direct Release Products.
The surfactants listed on the Safer Chemical Ingredients List (SCIL) include mixtures with varying chain lengths, degrees of branching, and numbers of ethoxyl (EO) and propoxyl (PO) groups. These structural characteristics determine the aquatic toxicity and rate of biodegradation of the chemical. Safer Choice may require additional structural information and/or test data to assess surfactants listed on SCIL for use in labeled products.
|Acute Aquatic Toxicity (L/E/IC50 Value)1||Rate of Biodegradation|
|≤1 ppm||May be acceptable if biodegradation2 occurs within a 10-day window without products of concern 3|
|>1 ppm and ≤10 ppm||Biodegradation2 occurs within a 10-day window without products of concern3|
|>10 ppm||Biodegradation2 occurs within 28 days without products of concern3|
1. In general, there is a predictable relationship between acute aquatic toxicity and chronic aquatic toxicity for organic chemicals (i.e., chemicals that have high acute aquatic toxicity also have high chronic aquatic toxicity). Since acute aquatic toxicity data are more readily available, the Safer Choice Criteria use these data to screen chemicals that may be toxic to aquatic life (see Sections 5.9 and 6.8 of the Safer Choice Master Criteria for Safer Ingredients).