Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

Biodegradation in water:

One experimental (key study, reliability 2) and two QSAR predictions (supporting study and disregarded study, reliability 2) are available for the substance 2,4,6 -triisopropyl-m-phenylene diisocyanate. The experimental study was conducted according to EU Method C.4 -D (Müller, 1997). No degradation (0 %) was observed after 4, 14 and 28 days. However, the substance was not found to be bacteriotoxic. .

The first prediction for biodegradability was performed with the computer program BIOWIN v4.10 (EPIWIN software) by US-EPA (Chemservice S.A., 2011). As overall prediction result the substance is not readily biodegradable, neither under aerobic nor under anaerobic conditions.

Further prediction was performed with the help of the Start plug-in in Toxtree (v.2.1.0) by Chemservice S.A. (2011). The chemical was assigned to the class III - unknown.

Biodegradation in water and sediment:

No exposure to water and sediment is intended during the life cycle of the test substance. Indirect exposure to the environment is unlikely, which is also indicated by the manufacturing process. In accordance with REACH, Annex IX, Section, column 2, this endpoint can be waived.

Biodegradation in soil:

One publication is available to assess the possibilities of the liberation of toxic aromatic amines under different conditions of disposal (Martens, 1981). The degradation of different 14C-labelled polyurethane foams was investigated in the leachate of a refuse tip, in composted municipal waste and in an agricultural soil. With unlabelled foam cubes experiments were run under the environmental conditions of a refuse tip. The degradation of 14C-labelled polyureas was studied in different agricultural soils. In the laboratory tests the criteria of degradation were the liberation of aromatic amines and the production of 14CO2. The degradation in the refuse tip was estimated on the basis of weight loss.

From the results it can be assumed that the polyether based polyurethane foams are largely resistant to microbial as well as chemical attack under all practical conditions of disposal. Polyester based polyurethane foams are susceptible to chemical hydrolysis favoured by extreme environmental conditions such as high temperature and/or low or high pH values. Under these circumstances an accumulation of aromatic amines can occur if their further microbial degradation is impeded by the lack of suitable conditions for the growth of microorganisms. No indication of any degradation of the isocyanate based polyureas was found.