Registration Dossier

Environmental fate & pathways

Biodegradation in water: screening tests

Currently viewing:

Administrative data

Link to relevant study record(s)

Description of key information

No biodegredation was observed in ready biodegradability tests. No biodegredation was observed in SCAS tests. Under nitrogen limiting conditions microbial growth was observed.

Key value for chemical safety assessment

Additional information

TEPA is not biodegraded in (standard and prolonged) Closed Bottle test and should therefore not be classified as readily biodegradable (Biodegradation of various polyethylene amines,van Ginkel 1990; Biodegradation of higher ethylene polyamines, van Ginkel 1990).Toxicity of TEPA to the competent microorganisms and the stringency of the test procedures could account for the recalcitrance of TEPA in the Closed Bottle test. Results obtained in the Semi-Continuous Activated Sludge (SCAS) test (inherent biodegradability test) also illustrate that TEPA is not completely (ultimately) biodegradable through growth-linked processes. The partial removal of TEPA in the SCAS test was attributed to adsorption onto the activated sludge particles. (removal of higher ethylene polyamines in the SCAS test, van Ginkel 1992). It is unlikely that growth linked biodegradation of TEPA will occur in the environment.

However, co-metabolic transformation of TEPA has been demonstrated in batchexperiments. In these experiments PEHA was used as sole nitrogen source. Various natural organic compounds may act as carbon source.

This finding demonstrates that PEHA can be utilized by microorganisms as nitrogen source in the environment.(Triethylenetetramine as a soule source of nitrogen for microbial growth, van Ginkel 1992).