Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Reactive Blue 50 is not readily 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 40069 was tested in tests evaluating Biological Oxygen Demand (BOD5) and Chemical Oxygen Demand (COD). BOD5 and COD values of 24 and 787.94 mg O2/g were determined for FAT 40069/A. Based on the BOD5/COD quotient which is not >0.5, the substance is not indicative of rapid degradation. The Biological elimination i.e. percent degradation of FAT 40069/A is found to be 19 %. Taking above data into account, FAT 40069 is considered to be not readily biodegradable.