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DfE Screens for Safer Chemical Ingredients
| Surfactants: Direct Release Products |
Each ingredient in a formulation has a role to play in making a product work. Whether it is to aid in cleaning by reducing surface tension (surfactants), dissolve or suspend materials (solvents), reduce water hardness (chelating agents), or provide a scent (fragrances), each ingredient type has a function. Within these "functional classes," many ingredients share similar toxicological and environmental fate characteristics. As a result, DfE focuses its review of formulation ingredients on the key (environmental and human health) characteristics of concern within a functional class. This approach allows formulators to use those ingredients with the lowest hazard in their functional class, while still formulating high-performing products.
From the beginning of the Formulator Program (started in 1997), DfE has used the technical expertise of its workgroup of EPA scientists to compare ingredients in the same functional class and thereby identify those ingredients with the safest hazard profile. The program is now developing DfE Screens for safer chemical ingredients to share this expertise and make it easier to formulate safer products. The solvents & surfactants screens were developed to identify safer chemical ingredients for cleaning products. DfE is also developing screens for other functional ingredient classes.
DfE Screen for Solvents in Cleaning Products
With cleaning solvents, there are potential concerns for the following endpoints: carcinogenicity, acute mammalian toxicity, reproductive and developmental toxicity, repeated-dose toxicity, neurotoxicity, and environmental fate and toxicity. Phase I of the solvents screen should be applied only to alcohols, esters, ethylene glycol ethers, and propylene glycol ethers. DfE’s next step is to expand the solvents screen to additional solvent classes used in cleaning products, such as terpenes, amines, and amides; these will be known as Phase II solvent classes.
DfE is interested in gaining experience with Phase I of the solvents screen as it is applied by DfE and third-party reviewers for CleanGredients, and will use that experience to inform future iterations of the screen. The DfE Screen for Solvents (PDF) (16 pp, 130K, About PDF) is available here as a pdf document.
PHASE I SOLVENT CLASSES |
Alcohols |
ATTRIBUTES OF CONCERN FOR PHASE I SOLVENTS |
Carcinogenicity |
DfE Screens for Surfactants
Surfactants in cleaning products are distinguished by their rate of biodegradation and level of aquatic toxicity. The DfE Screen for Surfactants combines those two hazard characteristics, and requires that surfactants with higher aquatic toxicity demonstrate a faster rate of biodegradation. Surfactants that meet the relevant screen for product use are acceptable for use in a DfE-recognized cleaning product.
Acute Aquatic Toxicity |
Rate of Biodegradation |
≤1 ppm |
May be acceptable if biodegradation1 occurs within a 10-day window |
>1 ppm and ≤10 ppm |
Biodegradation1 occurs within a 10-day window |
| >10 ppm | Biodegradation1 occurs within 28 days without products of concern2 |
1. Generally, >60% mineralization (to CO2 and water) in 28 days.
2. Products of concern are compounds with high acute aquatic toxicity (L/E/IC50 ≤ 10ppm) and a slow rate of biodegradation (greater than 28 days).
Certain products that are intended for use outdoors are likely to bypass sewage treatment, shortening the time for degradation prior to entering sensitive environments. For these products, like boat cleaners and graffiti removers, DfE has raised the bar in its standard surfactant screen to address the potential for immediate contact with aquatic life.
| Acute Aquatic Toxicity Value (L/E/IC50)1 | Persistence (Measured in terms of rate of biodegradation) |
Status | |
| 1 | ≤1 ppm | Not acceptable | |
| 2 | >1 ppm and ≤10 ppm | Biodegradation2 must occur within a 10-day window | Could be improved |
| 3 | >10 ppm and <100 ppm | Biodegradation2 occurs within 28 days without products of concern3 | Could be improved |
| Biodegradation2 occurs within a 10-day window | Acceptable | ||
| 4 | ≥100 ppm | Biodegradation2 occurs within 28 days without products of concern3 | Acceptable |
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 DfE Screens use these data to screen chemicals that may be toxic to aquatic life.
2. Generally, >60% mineralization (to CO2 and water).
3. Products of concern are compounds with high acute aquatic toxicity (L/E/IC50 ≤ 10ppm) and a slow rate of biodegradation (greater than 28 days).
Formulators who subscribe to the CleanGredients® database can find a list of surfactants that meet the DfE Screen. Suppliers who subscribe can have their surfactants reviewed against the screen and listed in the database. Nearly 300 formulators are finding safer surfactants on CleanGredients®.