9,10-Anthracenedione, 1,4-bis[(2-ethylhexyl)amino]-5,8-dihydroxy-

Biodegradation in water: screening tests

Description of key information

Evidence of ready biodegradability in a Carbon Dioxide Evolution Test is 60% TC02 w ithin the 28-day test period (1,2) In addition, the pass leve must be reached within 10 days of achieving 10% TC02 (1.2) The final mean percent biodegradation for Spectrace MD-810 Marker (Solvent free)
was 5. 3% Spectrace MD-8 10 Marker (Solvent free) may not be considered readily biodegradable. since 10% TC02 was not achieved

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable but failing 10-day window

Additional information

The ready biodegradability of Spectrace® MD-810 Marker (Solvent free) (Rohm and Haas Company TD

number 04-049; Lot number RWS-2-43; 95.23% active ingredient) was determined by the Carbon

Dioxide Evolution Test Method (OECD Guideline 301B) (Rohm and Haas Protocol Number 07P-023).

Tests of ready biodegradability are stringent tests that provide limited opportunity for acclimation and

biodegradation to occur. In the CO2 test, inoculated mineral medium was dosed with a known amount of

test substance as the nominal sole source of organic carbon and aerated with CO2-free air. The CO2

produced from the mineralization of organic carbon within the test chambers was displaced by the flow of

CO2-free air and trapped as K2CO3 in KOH trapping solution. The amount of CO2 produced by the test

substance (corrected for that evolved by the blank inoculum) is expressed as a percentage of the

theoretical amount of CO2 (TCO2) that could have been produced if complete biodegradation of the test

substance occurred. The test contained a blank control group, a reference group, a treatment group and a

toxicity control. The blank control, reference and treatment groups each contained two replicate test

chambers. The blank control was used to measure the background CO2 production of the inoculum and

was not dosed with a carbon source. The reference chambers were dosed with sodium benzoate, a

substance known to be biodegradable, at a nominal concentration of 10 mg C/L. The treatment group test

chambers were used to evaluate Spectrace® MD-810 Marker (Solvent free) at a nominal concentration of

approximately 10 mg C/L. The toxicity control was used to evaluate toxicity of the test substance to the

inoclum and was dosed with both the reference and test substances at 10 mg C/L each. The results

indicated that the activated sludge inoculum was active; degrading the reference substance 99.4%. The

average cumulative percent biodegradation for Spectrace® MD-810 Marker (Solvent free) was 5.3%.