Registration Dossier

Diss Factsheets

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Based on the evaluation of existing data and based on the estimation by EPIWIN, the substance is considered not readily biodegradable.

Additional information

According to OECD guideline 302B, no biodegradation of Direct Red 23 (DR23) based on CO2 evolution and calculated as % ThCO2 was observed in the Clariant key study (Clariant, 2007), where less than 20% degradation was attained after 28 days of contact time. This outcome was confirmed by the result of the second Clariant key study of 2002 (Clariant, 2002).

Further supporting studies on DR23 (Boruta, 1995) and on a similar azo-dye (Ciba, 1992 on Direct Red 262) support the conclusion that DR23 is not ready biodegradable.


Direct exposure of sediment and soil is unlikely; based on CSR and risk management measures reported there is no direct sediment and/or soil exposure.