Registration Dossier

Ecotoxicological information

Endpoint summary

Administrative data

Description of key information

There are three key experimental studies available. Two earthworm reproduction studies are available, one for p-xylene and one for mixed xylenes (CAS 1330 -20 -7; substance composition equivalent to reaction mass of ethylbenzene and mixed xylenes). The NOECs are as follows

p-xylene, NOEC = 71.1 mg/kg soil dw

mixed xylenes (CAS 1330 -20 -7; substance composition equivalent to reaction mass of ethylbenzene and mixed xylenes, NOEC = 42.6 mg/kg soil dw

One soil microflora study is available for mixed xylenes (CAS 1330 -20 -7; substance composition equivalent to reaction mass of ethylbenzene and mixed xylenes).

Respiration (C transformation), 28 d NOEC > 1000 mg/kg soil dw

Nitrate formation, 7 d EC50 = 867 mg/kg soil dw; 28 d NOEC > 1000 mg/kg soil dw.

Additional information

Due to the technical challenges of testing volatile substances, a validated TLM-EqP modeling framework was used to derive terrestrial effect values to act as supporting studies for terrestrial macro-organisms endpoints and to act as part of a weight of evidence approach for the terrestrial plant endpoint. These data were considered reliable; however, these were not used in the PNEC derivation. The hazard to soil organisms was assessed by using experimentally derived data and a conservative assessment factor of 50.

Available data in the literature published by government organisations (Environment Canada 2005) has been used as supporting data for terrestrial invertebrate endpoints and as part of the weight of evidence along with other literature sources for the terrestrial plant endpoint.