2,2'-(p-phenylenediethene-2,1-diyl)bisbenzonitrile

PBT assessment

PBT assessment: overall result

PBT status:

the substance is not PBT / vPvB

Justification:

Classification 2,2'-(p-Phenylenediethene-2,1-diyl)bisbenzonitrile for effects in the environment:

 

The chemical 2,2'-(p-Phenylenediethene-2,1-diyl)bisbenzonitrile (CAS no. 13001-39-3) isused for brightening and whitening ofterylene (polyester) fiber and has good whitening effect for polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), engineering plastic ABS and other plastics. It is also used in coating industry.The aim was to assess whether the PBT criterion within Annex XIII was fulfilled for 2,2'-(p-Phenylenediethene-2,1-diyl)bisbenzonitrile. 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

Estimate of probability of rapid biodegradation relying on BIOWIN v4.10 in EPI Suite prediction tool. The overall assessment is based on the responses given by different predictive models for biodegradability under various conditions: linear and non-linear models, ultimate and primary survey models, MITI linear and non-linear models, anaerobic linear model.The substance 2,2'-(p-Phenylenediethene-2,1-diyl)bisbenzonitrile(CAS no. 13001-39-3)was predicted to be not ready biodegradable.

 

As the half-life value of chemical 2,2'-(p-Phenylenediethene-2,1-diyl)bisbenzonitrileis not known and only predicted data is available for the substance, it has been concluded that chemical 2,2'-(p-Phenylenediethene-2,1-diyl)bisbenzonitrileis likely to be persistent (P) in nature.

 

Bioaccumulation assessment

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

 

The octanol water partition coefficient of the test chemical was estimated to be ranges from 6.149 to 6.32, 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.

 

Although the partition coefficient value indicate the chemical to be Very bioaccumulative (vB), since only predicted data is available for the substance, it has been concluded that chemical 2,2'-(p-Phenylenediethene-2,1-diyl)bisbenzonitrile is 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 in water (solubility: 0.024 mg/L at 25° C). The chemical 2,2'-(p-Phenylenediethene-2,1-diyl)bisbenzonitrile 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.