Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

FAT 93450/A is neither readily nor inherently biodegradable.

Additional information

By the nature of their design and use, textile dyes are not intended to be readily biodegradable as this would assist in the rapid destruction of the dyestuff, rendering it unfit for purpose. There are ISO, European, American (AATCC) and national standards for the colour fastness of dyes. Dyes are required to have specific fastness properties. If the dyes were biodegradable, it would not be possible for them to have these fastness properties. As such, it is accepted that such substances are not readily biodegradable under relevant environmental conditions. A published study (Pagga & Brown, 1986) describes the results of the testing of 87 dyestuffs in short-term aerobic biodegradation tests. The authors of this publication concluded that dyestuffs are very unlikely to show any significant biodegradation in such tests and that 'there seems little point in carrying out such test procedures’ on dyestuffs. Nevertheless, biodegradability of FAT 93450 was tested in a MITI test as well as test evaluating Chemical Oxygen Demand (COD). The inherent biodegradation study with FAT 93450/A(of ca. 96 % purity) was performed in an aerobic aqueous medium according to OECD Guideline 302C. The mean value of the biodegradation of test substance after 28 d was 0 %, while the reference substance after 14 d was biodegraded as 84 %. The biochemical oxygen demand (BOD5) after 5 d was 0 mg O2/g.The COD of FAT 93450/A was found to be 2018 mg O2/g in a study conducted according to DIN 38409 -H 41. Since the BOD5 after 5 days was zero, the BOD5/COD quotient is mathematically not defined. Under the study conditions, the test substance was not considered to be neither readily nor inherently biodegradable.