4-acetamido-5-[[4-[[2-(sulphooxy)ethyl]sulphonyl]phenyl]azo]anthranilic acid, sodium salt

PBT assessment

PBT assessment: overall result

PBT status:

the substance is not PBT / vPvB

Justification:

Classification of 2-amino-4-acetamido-5-[(E)-2-(4-{[2-(sulfooxy)ethane]sulfonyl}phenyl)diazen-1-yl]benzoic acid sodium for effects in the environment:

 

The chemical 2-amino-4-acetamido-5-[(E)-2-(4-{[2-(sulfooxy)ethane]sulfonyl}phenyl)diazen-1-yl]benzoic acid sodium (CAS no. 94158-82-4) is used in textile dyes for coloring cotton, wool, silk and polyamide textiles. The aim was to assess whether the PBT criterion within Annex XIII was fulfilled for 2-amino-4-acetamido-5-[(E)-2-(4-{[2-(sulfooxy)ethane]sulfonyl}phenyl)diazen-1-yl]benzoic acid sodium. 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

Biodegradability of test chemical 2-amino-4-acetamido-5-[(E)-2-(4-{[2-(sulfooxy)ethane]sulfonyl}phenyl)diazen-1-yl]benzoic acid sodium (CAS no. 94158-82-4) is predicted using OECD QSAR toolbox v.3.3 using log Kow as primary descriptor. The test chemical 2-amino-4-acetamido-5-[(E)-2-(4-{[2-(sulfooxy)ethane]sulfonyl}phenyl)diazen-1-yl]benzoic acid sodium undergoes 13.60 % biodegrdation by considering BOD as parameter and microorganisms as inoculum in 28 days. Based on percent biodegradability it is concluded that test chemical 2-amino-4-acetamido-5-[(E)-2-(4-{[2-(sulfooxy)ethane]sulfonyl}phenyl)diazen-1-yl]benzoic acid sodium is not readily biodegradable.

 

Estimation Programs Interface Suite (EPI suite, 2017) was run to predict the biodegradation potential of the test compound 2-amino-4-acetamido-5-[(E)-2-(4-{[2-(sulfooxy)ethane]sulfonyl}phenyl)diazen-1-yl]benzoic acid sodium (CAS no. 94158-82-4) in the presence of mixed populations of environmental microorganisms. 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  2-amino-4-acetamido-5-[(E)-2-(4-{[2-(sulfooxy)ethane]sulfonyl}phenyl)diazen-1-yl]benzoic acid sodium is expected to be not readily biodegradable.

 

Experimental results from the similar substances (CAS: 6034-54-4 and 3622-84-2) also indicate that they are not readily biodegradable

 

Environmental fate

According to the fugacity model levels III, the most likely environmental fate for this test chemical is soil (i.e.estimated to 60%). In soil,2-amino-4-acetamido-5-[(E)-2-(4-{[2-(sulfooxy)ethane]sulfonyl}phenyl)diazen-1-yl]benzoic acid sodiumwas expected to have rapid mobility based upon a Log KOC value ranging from 0 to 1.1302, respectively. The half-life in soil (360 days estimated by EPI suite) indicates that the chemical is very persistent in soil and the exposure risk to soil dwelling animals is moderate to high.

 

If released in to the environment, 43.3% of the chemical will partition into water according to the Mackay fugacity model level III in EPI suite version 4.1 (2017). However, the half-life (180 days estimated by EPI suite) indicates that the chemical is very persistent in water and the exposure risk to aquatic animals is moderate to high.

 

Moreover, its persistent characteristic is also observed in the sediment compartment with a half-life of 1620.833 days (estimated by EPI Suite version 4.1).

 

Although the half-life value indicate the chemical to be Very Persistent (vP), since only predicted data is available for the substance, it has been concluded that 2-amino-4-acetamido-5-[(E)-2-(4-{[2-(sulfooxy)ethane]sulfonyl}phenyl)diazen-1-yl]benzoic acid sodium is considered 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 database was determined to be ranges from 1 to 3.162 L/kg and theoctanol water partition coefficient of the test chemical is -4.5201 which is less than the threshold of 4.5. 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

All of the available short-term eco-toxicity estimations for invertebrates and algae for the substance indicates the LC50/EC50 value to be in the range 400.69– 675.47 mg/L. These value suggest that the substance is not likely to be hazardous to Aquatic organisms at environmentally relevant concentrations and can be considered to be ‘not classified’ as per the CLP regulation.

There are no available long-term toxicity evaluations for2-amino-4-acetamido-5-[(E)-2-(4-{[2-(sulfooxy)ethane]sulfonyl}phenyl)diazen-1-yl]benzoic acid sodium. By speculation, long-term NOEC for aquatic organisms were not expected for the substance at concentration below 0.01 mg/L based on the data mentioned above

 

The chemical was therefore not considered as hazardous to aquatic environments as per the criteria set out in Annex XIII.

 

Conclusion

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