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Environmental fate & pathways

Biodegradation in water: screening tests

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Description of key information

Not inherently biodegradable:
16.6% biodegradation in 28 days (OECD 302 C; ThOD NH4)
14.8% biodegradation in 28 days (OECD 302 C; ThOD NO3)

Key value for chemical safety assessment

Biodegradation in water:
under test conditions no biodegradation observed

Additional information

No experimental study investigating the ready biodegradability of UMA 121 is available. However, a study investigating the inherent biodegradability of UMA 121 is available. This study was carried out according to OECD Guideline 302C and GLP (Hammesfahr, 2013). Aerobic activated sludge from a domestic wastewater treatment plant was used as inoculum. Biodegradation after the 28-day test period was determined to be 16.6% or in case of nitrification 14.8%. In accordance with ECHA Guidance R.7b (ECHA, 2016) degradation of < 20% in an inherent biodegradability test according to OECD 302 would provide sufficient information to confirm persistence. Thus, additional tests investigating the ready biodegradability of UMA 121 and/or simulation tests in water, sediment and soil are not considered to be necessary based on the result from the inherent biodegradation study. In conclusion, UMA 121 is considered to be persistent in the environment.
HPMA as a constituent of UMA 121 might be freely available in the aquatic environment. However, experimental data show that HPMA is readily biodegradable according to the OECD criteria (Chemicals Evaluation and Research Institute Japan, 1995 & Rohm, 1994). Thus, it is expected that the substances is degraded quickly by activated sludge microorganisms.