4-[(1-amino-9,10-dihydro-4-hydroxy-9,10-dioxo-2-anthryl)oxy]-N-(3-ethoxypropyl)benzenesulphonamide

Endpoint summary

Description of key information

Disperse Red 092 is considered to be not biodegradable and immobile, however the hydrolysis rate could not be determined.

Additional information

By the nature of their design and use, disperse dyes are not intended to be readily biodegradable as this would assist in the rapid destruction of the dyestuff, rendering it unfit for purpose. 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. 

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. Experimental data on biodegradation potential of FAT 40444 also supports the conclusion that the substance is not biodegradable. No biodegradation was observed in a ready biodegradability study, while BOD5/COD ratio was equal to 0.13, indicating substance to be hardly biodegradable. In a study to investigate hydrolysis as a function of pH, FAT 40444 did not show consistent hydrolysis and hence, no hydrolysis rate can be determined. The adsorption coefficient FAT 40444/B TE has been determined to be 4.27 x 10⁵, log₁₀K_oc >5.63, hence FAT 40444 is considered to be immobile.