3-(1-(4-amino-3-methyl-5-sulphonatophenyl)-1-(4-amino-3-sulphonatophenyl)methylene)cyclohexa-1,4-dienesulphonic acid

PBT assessment

PBT assessment: overall result

PBT status:

the substance is not PBT / vPvB

Justification:

Classification of 3-(1-(4-amino-3-methyl-5-sulphonatophenyl)-1-(4-amino-3-sulphonatophenyl)methylene)cyclohexa-1,4-dienesulphonic acid for effects in the environment:

 

The chemical 3-(1-(4-amino-3-methyl-5-sulphonatophenyl)-1-(4-amino-3-sulphonatophenyl)methylene)cyclohexa-1,4-dienesulphonic acid (CAS no. 3244-88-0) is used in as a biological staining agent. The aim was to assess whether the PBT criterion within Annex XIII was fulfilled for 3-(1-(4-amino-3-methyl-5-sulphonatophenyl)-1-(4-amino-3-sulphonatophenyl)methylene)cyclohexa-1,4-dienesulphonic 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

Estimation Programs Interface Suite (EPI suite, 2017) was run to predict the biodegradation potential of the test compound (3-(1-(4-amino-3-methyl-5-sulphonatophenyl)-1-(4-amino-3-sulphonatophenyl)methylene)cyclohexa-1,4-dienesulphonic acid(CAS no. 3244 -88 -0) 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 chemical3-(1-(4-amino-3-methyl-5-sulphonatophenyl)-1-(4-amino-3-sulphonatophenyl)methylene)cyclohexa-1,4-dienesulphonic acidis expected to be not readily biodegradable.

 

Experimental results from the similar substances (CAS: 81-11-8) also indicate that it is not readily biodegradable

 

Environmental fate

According to the fugacity model levels III, the most likely environmental fate for this test chemical is sediment and soil (i.e.estimated to 60.5% and 37.3% respectively).Thehalf-life in soil (541.6 days in sediment and 120 days in soil as estimated by EPI suite) indicates that the chemical is persistent in sediment but not persistent in soil.

 

If released in to the environment, 2.2% of the chemical will partition into water and sediment according to the Mackay fugacity model level III in EPI suite version 4.1 (2017). However, the half-life (60 days in water as estimated by EPI suite) indicates that the substance is persistent in water.

 

Although the half-life values indicate the chemical to be Very persistent (vP), since only predicted data is available for the substance, it has been concluded that 3-(1-(4-amino-3-methyl-5-sulphonatophenyl)-1-(4-amino-3-sulphonatophenyl)methylene)cyclohexa-1,4-dienesulphonic acid is 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 2.38 – 3.16 and theoctanol water partition coefficient of the test chemical is -9.76 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 estimation for invertebrates and algae for the substance indicates the LC50/EC50 value to be >100 mg/L. These value suggest that the substance is likely to be non-hazardous at environmentally relevant concentrations and can be considered as “not classified” as per the CLP regulation.

 

There are no available long-term toxicity evaluations for 3-(1-(4-amino-3-methyl-5-sulphonatophenyl)-1-(4-amino-3-sulphonatophenyl)methylene)cyclohexa-1,4-dienesulphonic acid. By speculation, long-term NOEC for aquatic organisms cannot be expected for the substance at concentration below 0.01 mg/L based on the data mentioned above.

 

The chemical was therefore considered as non-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 fulfil 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.