6-[(2,4-diaminophenyl)azo]-3-[[4-[[4-[[7-[(2,4-diaminophenyl)azo]-1-hydroxy-3-sulpho-2-naphthyl]azo]phenyl]amino]-3-sulphophenyl]azo]-4-hydroxynaphthalene-2-sulphonic acid

PBT assessment

PBT assessment: overall result

PBT status:

the substance is not PBT / vPvB

Justification:

Classification of 6-[(2,4-diaminophenyl)azo]-3-[[4-[[4-[[7-[(2,4-diaminophenyl)azo]-1-hydroxy-3-sulpho-2-naphthyl]azo]phenyl]amino]-3-sulphophenyl]azo]-4-hydroxynaphthalene-2-sulphonic acid for effects in the environment:

 

The chemical 6-[(2,4-diaminophenyl)azo]-3-[[4-[[4-[[7-[(2,4-diaminophenyl)azo]-1-hydroxy-3-sulpho-2-naphthyl]azo]phenyl]amino]-3-sulphophenyl]azo]-4-hydroxynaphthalene-2-sulphonic acid (CAS no. 76186-07-7) is used in the dyestuff industry. The aim was to assess whether the PBT criterion within Annex XIII was fulfilled for 6-[(2,4-diaminophenyl)azo]-3-[[4-[[4-[[7-[(2,4-diaminophenyl)azo]-1-hydroxy-3-sulpho-2-naphthyl]azo]phenyl]amino]-3-sulphophenyl]azo]-4-hydroxynaphthalene-2-sulphonic acid. The PBT criterion was herein assessed based on experimental data in conjunction with standardized environmental fate models. Here follows a description of the PBT assessment.

 

 

Persistence assessment

The tested substance fulfils the P criterion within Annex XIII based on the assessment that here follows:

 

Biotic degradation

In a prediction done by SSS (2017) using OECD QSAR toolbox version 3.3 with logKow as the primary descriptor, percentage biodegradability of test chemical6-[(2,4-diaminophenyl)azo]-3-[[4-[[4-[[7-[(2,4-diaminophenyl)azo]-1-hydroxy-3-sulpho-2-naphthyl]azo]phenyl]amino]-3-sulphophenyl]azo]-4-hydroxynaphthalene-2-sulphonic acid(CAS No. 76186-07-7) was estimated.Test substance undergoes 0.2% degradation by BOD in 28 days. Thus, based on percentage degradation, the test chemical 6-[(2,4-diaminophenyl)azo]-3-[[4-[[4-[[7-[(2,4-diaminophenyl)azo]-1-hydroxy-3-sulpho-2-naphthyl]azo]phenyl]amino]-3-sulphophenyl]azo]-4-hydroxynaphthalene-2-sulphonic acid was estimated to be not readily biodegradable in water.

 

In another prediction using the Estimation Programs Interface Suite (EPI suite, 2017), the biodegradation potential of the test compound 6 -[(2,4 -diaminophenyl)azo]-3 -[[4 -[[4 -[[7 -[(2,4 -diaminophenyl)azo]-1 -hydroxy-3 -sulpho-2 -naphthyl]azo]phenyl]amino]-3-sulphophenyl]azo]-4-hydroxynaphthalene-2-sulphonic acid(CAS No. 76186-07-7) in the presence of mixed populations of environmental microorganisms was estimated. The biodegradability of the substance was calculated using seven different models such as Linear Model, Non-Linear Model, Ultimate Biodegradation Timeframe, Primary Biodegradation Timeframe, MITI Linear Model, MITI Non-Linear Model and Anaerobic Model (called as Biowin 1-7, respectively) of the BIOWIN v4.10 software. The results indicate that chemical 6 -[(2,4 -diaminophenyl)azo]-3 -[[4 -[[4 -[[7 -[(2,4 -diaminophenyl)azo]-1 -hydroxy-3 -sulpho-2 -naphthyl]azo]phenyl]amino]-3 -sulphophenyl]azo]-4 -hydroxynaphthalene-2 -sulphonic acid is expected to be not readily biodegradable.

 

Experimental study on read across substances (CAS: 6449-35-0 and 2429-74-5) also indicate the substance to be not readily biodegradable.

 

Hence it has been concluded that 6-[(2,4-diaminophenyl)azo]-3-[[4-[[4-[[7-[(2,4-diaminophenyl)azo]-1-hydroxy-3-sulpho-2-naphthyl]azo]phenyl]amino]-3-sulphophenyl]azo]-4-hydroxynaphthalene-2-sulphonic acid is likely to be persistent in nature.  

 

Bioaccumulation assessment

The tested substance does not fulfil the B criterion within Annex XIII based on the assessment that here follows:

 

Theestimated BCF value from authoritative databases was determined to be in the range 1 – 10. If this chemical is released into the aquatic environment, there should be a low risk for the chemical to bioaccumulate in fish and food chains.

 

Toxicity assessment

The tested substance does not fulfil the T criterion within Annex XIII based on the assessment that here follows:

 

Mammals

The tested chemical is regarded to be not classified for carcinogenicity, mutagenicity and reprotoxicity, Further, there is no evidence of chronic toxicity, as identified by the classifications STOT (repeated exposure), category 1(oral, dermal, inhalation of gases/vapours, inhalation of dust/mist/fume) or category 2 (oral, dermal, inhalation of gases/vapours, inhalation of dust/mist/fume).

 

Aquatic organisms

As per Column 2 (Annex VII and VIII) of the REACH regulation, a study does not need to be conducted if there are mitigating factors indicating that aquatic toxicity is unlikely to occur for instance if the substance is highly insoluble in water (solubility: 0.00000000506 mg/L). The chemical was therefore not considered as hazardous to aquatic environments as per the criteria set out in Annex XIII.

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Conclusion

Based on critical, independent and collective evaluation of information summarized herein, the tested compound fulfils the P criterion but does not fulfil the B and T criterion and has therefore not been classified as a PBT compound within Annex XIII.