1,8-dihydroxy-4-nitro-5-(phenylamino)anthraquinone

PBT assessment

PBT assessment: overall result

PBT status:

the substance is not PBT / vPvB

Justification:

Persistency assessment

In a study performed as per Zahn-Wellen test procedure which is similar to OECD guideline 302 B, Disperse Blue 077 (FAT 40278/A) was assessed for biodegradation potential at the end of the 28-days experimental period. The initial test substance concentration was 145 mg/l TOC. At the end of 28 days 49 % TOC was observed, indicating the test substance FAT 40278/A as not readily biodegradable.

The BOD5 and COD for FAT 40278/A were determined to be 47 and 1394 mg/g O2, respectively. Hence, the BOD5/COD ratio was 0.03, indicating it to be not readily biodegradable.

Based on above evidence, Disperse Blue 077 has been found to be not readily biodegradable and hence it can not be denied to be persistent or very persistent.

Bioaccumulation assessment

The n-octanol/water partition coefficient (log Pow) of Disperse Blue 077 was determined to be >6.9, this finding indicates low  bioaccumulation potential as this property is known to decrease for substances with log Kow greater than 6.5 and above.

Nonetheless, the bioaccumulation potential of Disperse Blue 077 has been assessed extensively by Environment Canada (Screening Assessment for the Challenge: 9,10-anthracenedione, 1,8-dihydroxy-4-nitro-5-(phenylamino)- (Disperse Blue 77), CAS No: 20241-76-3. Environment Canada, Health Canada. February, 2009.), which has been summarised below:

- Hu and Shen 2008 evaluated the bioconcentration of Disperse Blue 077 in Zebra fish (Brachydanio rerio) in a 28-day semi-static test with a test medium renewal every two days. Lack of detection in fish extracts (<0.02 mg/L) in this study suggested a limited solubility in lipids and/or limited potential to partition into fish tissue from aqueous systems—more likely both. The bioconcentration factor (BCF) was estimated to be <100.

- Several experimental fish bioaccumulation tests for disperse anthraquinone dyes, performed according to test methods specified by the Japanese Ministry of International Trade and Industry (MITI), reported log bioaccumulation factor (BCF) being < 0.7 (BCF < 5), expressed on the basis of wet body weight of the fishes (Anliker et al. 1981; Anliker and Moser 1987).

- The maximum diameter of Disperse Blue 077 and its conformers ranges from 1.28 to 1.55 nm (BBM 2008), which is within the range of diameters reported to be associated with slow bioaccumulation by Dimitrov (2005), suggesting that a potential for a reduced uptake rate and in vivo bioavailability exists with this dye.

Therefore, considering the overall weight of evidence, Disperse Blue 077 does not meet the bioaccumulation criterion. Thus, using the evidence presented above, Disperse Violet 057 can be considered as neither bioaccumulative (B) nor very bioaccumulative (vB).

Toxicity assessment

The substance is not classified as carcinogenic, mutagenic or reprotoxic according to Regulation EC No. 1272/2008. No long-term studies for marine or freshwater organisms are available. However, aquatic toxicity potential of substance Disperse Blue 077 was evaluated in studies conducted with fish, invertebrates, plants (Lemna) and bacteria. In an acute fish toxicity study conducted according to an internal Ciba guideline equivalent to OECD Guideline 203, the 96-hour LC50 of the test substance was determined to be 462 mg/L. The EC50 and EC100 values were found to be higher than 100 mg/L, in a short term toxicity study with daphnids. Exposure to Lemna minor did not produce any toxic effects at saturation concentration following 7 -days exposure. Based on the above details, it is evident that the LC50 values are >100 mg/L at all three trophic levels. Hence, the substance does not fulfill the T criterion.