5-[[p-(benzylmethylamino)phenyl]azo]-1,4-dimethyl-1H-1,2,4-triazolium chloride

PBT assessment

PBT assessment: overall result

PBT status:

the substance is not PBT / vPvB

Justification:

Classification of 5-[[p-(benzylmethylamino)phenyl]azo]-1,4-dimethyl-1H-1,2,4-triazolium chloride for effects in the environment:

 

The chemical5-[[p-(benzylmethylamino)phenyl]azo]-1,4-dimethyl-1H-1,2,4-triazolium chloride(CAS no. 29508-47-2) is used as a dyestuff for textiles. The aim was to assess whether the PBT criterion within Annex XIII was fulfilled for5-[[p-(benzylmethylamino)phenyl]azo]-1,4-dimethyl-1H-1,2,4-triazolium chloride.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 5-[[p-(benzylmethylamino)phenyl]azo]-1,4-dimethyl-1H-1,2,4-triazolium chloride (CAS: 29508-47-2) 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 that5-[[p-(benzylmethylamino)phenyl]azo]-1,4-dimethyl-1H-1,2,4-triazolium chloride (CAS: 29508-47-2) is expected to be not readily biodegradable.

Similar predicted data for the target chemical suggests that the Biodegradability of 5-[[p-(benzylmethylamino)phenyl]azo]-1,4-dimethyl-1H-1,2,4-triazolium chloride  (CAS: 29508-47-2) is predicted using OECD QSAR toolbox version 3.3 with log Kow as the primary descriptor. Test substance undergoes 0.91 % degradation by BOD in 28 days. Thus, based on percentage degradation, the test chemical 5-[[p-(benzylmethylamino)phenyl]azo]-1,4-dimethyl-1H-1,2,4-triazolium chloride  (CAS: 29508-47-2) was estimated to be not readily biodegradable in water.

The experimental studies for the similar substances (CAS: 509-34-2 and 10081-67-1) 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 84.3%).Thehalf-life in soil (120 days estimated by EPI suite) indicates that the chemical is persistent in soil.

 

If released in to the environment, 8.08% and 7.61% of the chemical will partition into sediment and water respectively, according to the Mackay fugacity model level III in EPI suite version 4.1 (2017). However, the half-life (60 days in water and 124 days in sediment estimated by EPI suite) indicates that the substance is persistent in both compartments.

 

Hence, it has been concluded that5-[[p-(benzylmethylamino)phenyl]azo]-1,4-dimethyl-1H-1,2,4-triazolium chlorideis likely to be persistent (P) in nature.

 

 

Bioaccumulation: aquatic/sediment

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

 

Theestimated BCF value from authoritative database was determined to be 3.162 and theoctanol water partition coefficient of the test chemical is 1.742 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

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 > 100 mg/L. These value suggest that the substance is likely to be non-hazardous to Aquatic organisms at environmentally relevant concentrations and can be considered as not classified as per the CLP regulation.

 

There are no long-term toxicity evaluation available for5-[[p-(benzylmethylamino)phenyl]azo]-1,4-dimethyl-1H-1,2,4-triazolium chloride. 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 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