1,4-dimethyl-5-[[4-[methylbenzylamino]phenyl]azo]-1H-1,2,4-triazolium acetate

PBT assessment

PBT assessment: overall result

PBT status:

the substance is not PBT / vPvB

Justification:

Classification of 1,4-dimethyl-5-[[4-[methylbenzylamino]phenyl]azo]-1H-1,2,4-triazolium acetate for effects in the environment:

 

The chemical 1,4-dimethyl-5-[[4-[methylbenzylamino]phenyl]azo]-1H-1,2,4-triazolium acetate (CAS no. 84000-82-8) is used as a dye in paper and textile industry. The aim was to assess whether the PBT criterion within Annex XIII was fulfilled for 1,4-dimethyl-5-[[4-[methylbenzylamino]phenyl]azo]-1H-1,2,4-triazolium acetate. 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 of1,4-dimethyl-5-[[4-[methylbenzylamino]phenyl]azo]-1H-1,2,4-triazolium acetate(CAS no. 84000-82-8)is predicted using QSAR toolbox version 3.3 with logKow as the primary descriptor. Test substance undergoes 0.92% degradation by considering BOD as parameter and microorganisms as inoculum in 28 days. On the basis of this percent biodegradability value it can be concluded that test chemical 1,4-dimethyl-5-[[4-[methylbenzylamino]phenyl]azo]-1H-1,2,4-triazolium acetate is not readily biodegradable.

 

Estimation Programs Interface Suite (EPI suite, 2017) was run to predict the biodegradation potential of the test compound 1,4-dimethyl-5-[[4-[methylbenzylamino]phenyl]azo]-1H-1,2,4-triazolium acetate(CAS no. 84000-82-8)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 chemical1,4-dimethyl-5-[[4-[methylbenzylamino]phenyl]azo]-1H-1,2,4-triazolium acetate is expected to be not readily biodegradable.

                                                                 

Experimental results from the read across substances (CAS: 92-59-1 and 121-69-7) also indicate that they are not readily biodegradable.

 

As the half-life value of chemical1,4-dimethyl-5-[[4-[methylbenzylamino]phenyl]azo]-1H-1,2,4-triazolium acetateis not known and only predicted data is available for the substance, it has been concluded thatchemical 1,4-dimethyl-5-[[4-[methylbenzylamino]phenyl]azo]-1H-1,2,4-triazolium acetateis likely to be persistent (P) 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 0.5 L/Kg, respectively and theoctanol water partition coefficient of the test chemical1,4-dimethyl-5-[[4-[methylbenzylamino]phenyl]azo]-1H-1,2,4-triazolium acetatewas determined to be 1.5 respectively, 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 fish, invertebrates and algae for the substance indicates the LC50/EC50 value to be in the range 113.56 – 251.651 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 for 1,4-dimethyl-5-[[4-[methylbenzylamino]phenyl]azo]-1H-1,2,4-triazolium acetate. 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 fulfil the B and T criterion and has therefore not been classified as a PBT compound within Annex XIII.