1. Primary. Alteration of the chemical structure of a substance resulting in loss of a specific property of that substance.
2. Ultimate. Complete breakdown of a compound to either fully oxidized or reduced simple molecules (such as carbon dioxide/methane, nitrate/ammonium, and water).
It should be noted that the products of biodegradation can be more harmful than the substance degraded.
The biodegradation heading in CleanGredients® refers to the rate of aerobic biodegradation based on standard test methods. For more detailed information regarding the definitions of "Ready Biodegradation" and "Ultimate Biodegradation" for specific ingredient classes in CleanGredients®, see the relevant Ingredient Attributes pages.
For listing in CleanGredients®, biodegradation testing is required. Biodegradation testing may be performed on either:
- the ingredient/preparation or
- the individual components that make up the ingredient/preparation.
- Include a disclaimer: "Data reflects the blend, not the individual components."
For evaluation against the DfE Screen
- Biodegradation will be evaluated based on review of the individual components
- Biodegradation data for blends may be reviewed on a case-by-case basis
- The potential for degradation products of concern will be considered as part of the biodegradation review.
Acceptable tests include:
- Methods: OECD 301 A-F and 303A (>80% removal) are recommended but other biodegradation data will be accepted to supplement these results.
- Data on analogs, consortium reviews, QSAR are allowed as additional evidence for biodegradation.
- Literature references must be included if test data are not provided.
| Ready Biodegradation | Ultimate Biodegradation in 28 days | Other Biodegradation Data |
|---|---|---|
|
>60% ThOD/ThCO2 (>70% DOC) in 28 days Meets 10-day window Also allow 14 days from start of test (OECD) |
>60% ThOD/ThCO2 (>70% DOC) in 28 days Does not meet 10-day window |
See optional supplemental tests |
A substance attaining the 60% mineralisation threshold level using an OECD 301 test method would be expected to undergo fast and virtually complete ultimate biodegradation in the aquatic environment, i.e. to mineralisation and biomass formation.
Note that older OECD biodegradation test methods did not include measurement of the 10-day window. Some surfactants may be readily biodegradable but will report that the 10-day window was not tested.
Report ingredient and/or component biodegradability as Ready, Ultimate or Other.
Note that while the database will accept numerical data for % degradation, the Formulator View will show that the value is greater or less than 60% in 28 days. The intent is to show whether or not the biodegradation rate meets the 60% cut off.
Report if the biodegradation test meets the 10-day window as Yes, No or did not test.