N-phenyl-4-[[4-(phenylamino)phenyl][4-(phenylimino)cyclohexa-2,5-dien-1-ylidene]methyl]aniline monohydrochloride

PBT assessment

PBT assessment: overall result

PBT status:

the substance is not PBT / vPvB

Justification:

Classification of N-phenyl-4-[[4-(phenylamino)phenyl][4-(phenylimino)cyclohexa-2,5-dien-1-ylidene]methyl]aniline monohydrochloridefor effects in the environment:

 

The chemicalN-phenyl-4-[[4-(phenylamino)phenyl][4-(phenylimino)cyclohexa-2,5-dien-1-ylidene]methyl]aniline monohydrochloride(CAS no. 2152-64-9) is usedin inks, printing, jet inks and wood stains, respectively. The aim was to assess whether the PBT criterion within Annex XIII was fulfilled for N-phenyl-4 -[[4 -(phenylamino)phenyl][4 -(phenylimino)cyclohexa-2,5 -dien-1 -ylidene]methyl]aniline monohydrochloride. 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 N-phenyl-4-[[4-(phenylamino)phenyl][4-(phenylimino)cyclohexa-2,5-dien-1-ylidene]methyl]aniline monohydrochloride (CAS no. 2152 -64 -9) is predicted using OECD QSAR toolbox version 3.3 with logKow as the primary descriptor. Test substance undergoes 0.286% degradation by BOD in 28 days. Thus, based on percentage degradation, the test chemical N-phenyl-4-[[4-(phenylamino)phenyl][4-(phenylimino)cyclohexa-2,5-dien-1-ylidene]methyl]aniline monohydrochloride was estimated to be not readily biodegradable in water.

 

Estimation Programs Interface Suite (EPI suite, 2017) was run to predict the biodegradation potential of the test compound N-phenyl-4 -[[4 -(phenylamino)phenyl][4 -(phenylimino) cyclohexa-2,5 -dien-1 -ylidene]methyl]aniline monohydrochloride (CAS no. 2152 -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 N-phenyl-4 -[[4 -(phenylamino)phenyl][4 -(phenylimino)cyclohexa-2,5 -dien-1-ylidene]methyl]aniline monohydrochloride is expected to be not readily biodegradable.

 

Experimental results from the similar substances (CAS: 2465-27-2, 101-61-1 and 91-76-9) 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 (i.e.estimated to 62.4%). The half-life in sediment (541.66 days estimated by EPI suite) indicates that the chemical is very persistent in sediment.

 

If released in to the environment, 36.5% of the chemical will partition into soil according to the Mackay fugacity model level III in EPI suite version 4.1 (2017). In soil,N-phenyl-4-[[4-(phenylamino)phenyl][4-(phenylimino)cyclohexa-2,5-dien-1-ylidene]methyl]aniline monohydrochloridewas expected to have negligible mobility based upon a Log KOC value 5.117. However, the half-life (120 days estimated by EPI suite) indicates that the chemical is not persistent in soil and the exposure risk to soil dwelling animals is moderate to low.

 

Moreover, its persistent characteristic is also observed in the water compartment with a half-life of 60 days (estimated by EPI Suite version 4.1).

 

Although the half-life value in sediment compartment indicate the chemical to be Very Persistent (vP), since only predicted data is available for the substance, it has been concluded thatN-phenyl-4-[[4-(phenylamino)phenyl][4-(phenylimino)cyclohexa-2,5-dien-1-ylidene]methyl]aniline monohydrochlorideis considered to be persistent in nature.

 

Bioaccumulation assessment

The tested substance fulfils the B criterion within Annex XIII based on the assessment that here follows:

 

Theestimated BCF value from authoritative database was determined to be 4839 L/Kg, respectively and theoctanol water partition coefficient of the test chemical is 6.01 which is greater than the threshold of 4.5. If this chemical is released into the aquatic environment, there should be a high risk for the chemical to bioaccumulate in fish and food chains.

 

Thus, the BCF value indicate that the chemicalN-phenyl-4-[[4-(phenylamino)phenyl][4-(phenylimino)cyclohexa-2,5-dien-1-ylidene]methyl]aniline monohydrochlorideis bioaccumulative (B) infish 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

As per Column 2 (Annex VIII) of the REACH regulation,testing for this end point is considered scientifically unjustified since there are mitigating factors indicating that aquatic toxicity is unlikely to occur as the substance is highly insoluble (solubility: 0.002081 mg/L at 25° C) in water and also having the partition coefficient 6.01. 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 and B criterion but does not fulfil the T criterion and has therefore not been classified as a PBT compound within Annex XIII.