2-amino-2-methylpropanol

Biodegradation in water: screening tests

Description of key information

Pure AMP (CAS 124-68-5, 98.4% pure) tested in OECD 301F at 11.1 mg/L was degraded by 89.3%, 90.9% and 98.1% within 28 days based on O2 consumption (based on ThOD-NH3 and corrected for measured nitrate and nitrite production), CO2 evolution and DOC removal, resp. The 10-day window was met. AMP is thus readily biodegradable under these conditions.

Using QSAR, all 7 Biowin models predict AMP to be readily biodegradable. Based on the consistency between predicted and experimental biodegradability of analogues, these predictions are expected to be very reliable. 

4 supportive studies evidence that the substance is at least inherently biodegradable, and easily biodegradable under specific conditions. In all of them, the way degradation was calculated was either improper or not described, so results are indicative:

• Pure AMP (CAS 124-68-5, 98.4% pure) tested in OECD 301F at 100 mg/L was degraded within 28 days by 45% based on O2 consumption (from ThOD-NO3) and degraded by 94% based on DOC removal. There was no info allowing to check the 10-day window for DOC removal. O2 consumption was based on ThOD-NO3 although no significant nitrite or nitrate evolution occurred. As a result, degradation based on O2 consumption is underestimated.


• Industrial grade AMP (CAS 124-68-5, 93-95% pure, with 5-7% MMAMP impurity CAS 27646-80-6) tested in a German DIN 38 protocol at 560 mg/L was degraded by 50% within 28 days based on O2 consumption from COD.


• An industrial mixture (89-90% of CAS 124-68-5, water, and 5-7% MMAMP impurity CAS 27646-80-6) was degraded by 66% at 2.5 m/L, 41% at 100 mg/L and 8% at 4000 mg/L, within 28 days. This was tested according to a wastewater handbook method and based on O2 consumption from BOD. The results evidence concentration-dependent degradability. This potentially suggests inhibition of microbial activity. However the report is a one-page abstract.


• A less concentrated industrial mixture (83-85% of CAS 124-68-5, water, and 5-6% MMAMP impurity CAS 27646-80-6) tested in OECD 301D at 2 mg/L was degraded by 39.8% within 28 days based on O2 consumption from BOD. 


• In the last 3 studies, there was no information on how exactly degradation was calculated. This limits the accuracy of the results due to test item impurities and potential nitrification.

MMAMP (CAS 27646-80-6, secondary amine impurity present in the boundary composition of AMP CAS 124-68-5) was not readily biodegradable and was less biodegradable than AMP in similar testing conditions:

- OECD 301D (2016, 25 mg/L): 15% degradation over 28 days

- OECD 301C (2001, 100 mg/L): <=3% degradation over 28 days

AMP industrial grades contain potentially up to 7% of the low-degradable MMAMP and this may interfere with biodegradation results. The pure substance AMP should be considered as readily biodegradable in order to allow uses of the pure substance to be properly assessed (e.g. products used in cosmetics have less than 0.5% secondary amine impurities).

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable