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Classification & Labelling & PBT assessment

PBT assessment

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Administrative data

PBT assessment: overall result

PBT status:
the substance is not PBT / vPvB

Classification of 1,3-Benzenedisulfonic acid, 4-[[5-(aminocarbonyl)-1-ethyl-1,6-dihydro-2-hydroxy-4-methyl-6-oxo-3-pyridinyl]azo]-6-[[4-[[3-[(4-amino-6-chloro-1,3,5-triazin-2-yl)amino]-4-sulfophenyl]amino]-6-chloro-1,3,5-triazin-2-yl]amino]- for effects in the environment:


The chemical 1,3-Benzenedisulfonic acid, 4-[[5-(aminocarbonyl)-1-ethyl-1,6-dihydro-2-hydroxy-4-methyl-6-oxo-3-pyridinyl]azo]-6-[[4-[[3-[(4-amino-6-chloro-1,3,5-triazin-2-yl)amino]-4-sulfophenyl]amino]-6-chloro-1,3,5-triazin-2-yl]amino]- (CAS no. 93941-80-1) is used in as a biological staining agent. The aim was to assess whether the PBT criterion within Annex XIII was fulfilled for 1,3-Benzenedisulfonic acid, 4-[[5-(aminocarbonyl)-1-ethyl-1,6-dihydro-2-hydroxy-4-methyl-6-oxo-3-pyridinyl]azo]-6-[[4-[[3-[(4-amino-6-chloro-1,3,5-triazin-2-yl)amino]-4-sulfophenyl]amino]-6-chloro-1,3,5-triazin-2-yl]amino]-. 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 4-{[4-({3-[(4-amino-6-chloro-1,3,5-triazin-2-yl)amino]-4-sulfophenyl}amino)-6-chloro-1,3,5-triazin-2-yl]amino}-6-[(E)-2-(5-carbamoyl-1-ethyl-2-hydroxy-4-methyl-6-oxo-1,6-dihydropyridin-3-yl)diazen-1-yl]benzene-1,3-disulfonic acid (CAS no. 93941-80-1) was predicted using OECD QSAR tool box v3.3 using log kow as primary descriptor. The test chemical 4-{[4-({3-[(4-amino-6-chloro-1,3,5-triazin-2-yl)amino]-4-sulfophenyl}amino)-6-chloro-1,3,5-triazin-2-yl]amino}-6-[(E)-2-(5-carbamoyl-1-ethyl-2-hydroxy-4-methyl-6-oxo-1,6-dihydropyridin-3-yl)diazen-1-yl]benzene-1,3-disulfonic acid  showed 2.38 % biodegradation in 28 days by taking BOD as parameter and microorganisms as inoculum. Therefore it is concluded that this test chemical is not readily biodegradable.


Another prediction done by using Estimation Programs Interface Suite (EPI suite, 2017) to estimate the biodegradation potential of the test compound 4-{[4-({3-[(4-amino-6-chloro-1,3,5-triazin-2-yl)amino]-4-sulfophenyl}amino)-6-chloro-1,3,5-triazin-2-yl]amino}-6-[(E)-2-(5-carbamoyl-1-ethyl-2-hydroxy-4-methyl-6-oxo-1,6-dihydropyridin-3-yl)diazen-1-yl]benzene-1,3-disulfonic acid (CAS no. 35642-64-9) 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  4-{[4-({3-[(4-amino-6-chloro-1,3,5-triazin-2-yl)amino]-4-sulfophenyl}amino)-6-chloro-1,3,5-triazin-2-yl]amino}-6-[(E)-2-(5-carbamoyl-1-ethyl-2-hydroxy-4-methyl-6-oxo-1,6-dihydropyridin-3-yl)diazen-1-yl]benzene-1,3-disulfonic acid is expected to be not readily biodegradable.


Experimental results from the similar substances (CAS: 1163-19-5 and 27676-62-6) 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 sediment and soil (i.e.estimated to 56.0% and 43.3% respectively).Thehalf-life (1620.83 days in sediment and 360 days in soil as estimated by EPI suite) indicates that the chemical is persistent in both compartments.


If released in to the environment, 0.649 % 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 (180 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 1,3-Benzenedisulfonic acid, 4-[[5-(aminocarbonyl)-1-ethyl-1,6-dihydro-2-hydroxy-4-methyl-6-oxo-3-pyridinyl]azo]-6-[[4-[[3-[(4-amino-6-chloro-1,3,5-triazin-2-yl)amino]-4-sulfophenyl]amino]-6-chloro-1,3,5-triazin-2-yl]amino]- 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 1.0 – 3.162 and theoctanol water partition coefficient of the test chemical is 1.96 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:



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 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. The test substance was determined to be highly insoluble in water (solubility= 0.059 mg/L). The chemical was therefore not considered as hazardous to aquatic environments as per the criteria set out in Annex XIII.



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.