1,5-bis(cyclohexylamino)anthraquinone

PBT assessment

PBT assessment: overall result

PBT status:

the substance is not PBT / vPvB

Justification:

Classification of 1,5-bis(cyclohexylamino)anthraquinone for effects in the environment:

 

The chemical 1,5-bis(cyclohexylamino)anthraquinone (CAS no. 3244-88-0) is used in as a colourant for plastics. The aim was to assess whether the PBT criterion within Annex XIII was fulfilled for 1,5-bis(cyclohexylamino)anthraquinone 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

In a prediction done by SSS (2017) using OECD QSAR toolbox version 3.4 with log Kow as the primary descriptor, percentage biodegradability of test chemical1,5-bis(cyclohexylamino)-9,10-dihydroanthracene-9,10-dione(CAS No. 15958-68-6) was estimated. Test substance undergoes 0.86% degradation by BOD in 28 days. Thus, based on percentage degradation, the test chemical 1,5 -bis(cyclohexyl amino)-9,10 -dihydroanthracene-9,10-dione was estimated to be not readily biodegradable in water.

 

In another prediction using the Estimation Programs Interface Suite (EPI suite, 2017), the biodegradation potential of the test compound1,5-bis(cyclohexylamino)-9,10-dihydroanthracene-9,10-dione(CAS No. 15958-68-6) in the presence of mixed populations of environmental microorganisms was estimated. 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 1,5 -bis(cyclohexyl amino)-9,10 -dihydroanthracene-9,10-dione is expected to be not readily biodegradable..

 

Experimental results from the similar substances (CAS: 117-79-3; 129-43-1 and 82-45-1) 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 soil (i.e.estimated to 91.2%).Thehalf-life in soil (120 days in soil as estimated by EPI suite) indicates that the chemical is not persistent in soil.

 

If released in to the environment, 8.61% and 0.217% 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 and 541.6 days in sediment as estimated by EPI suite) indicates that the substance is persistent in both the compartments.

 

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 1,5-bis(cyclohexylamino)anthraquinone is 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 in the range 13.2 - 112000 and theoctanol water partition coefficient of the test chemical is 9.34 which is more than the threshold of 4.5. If this chemical is released into the aquatic environment, there should be a moderate to high risk for the chemical to bioaccumulate in fish and food chains.

 

Although the BCF value indicate the chemical to be Very bioaccumulative (vB), since only predicted data is available for the substance, it has been concluded that 1,5-bis(cyclohexylamino)anthraquinone is bioaccumulative 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, 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= 0.0000024 mg/L). 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 fulfil 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.