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PBT assessment

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PBT assessment: overall result

PBT status:
the substance is not PBT / vPvB
Justification:

Classification of 2,2'-(ethene-1,2-diyldi-4,1-phenylene)bis(1,3-benzoxazole)for effects in the environment:

 

The chemical 2,2'-(ethene-1,2-diyldi-4,1-phenylene)bis(1,3-benzoxazole) (CAS no. 1533-45-5) is used as a colorants in inks, plastic, rubber and paint etc.. It is used for whitening chemical fibers, such as the polyester fibre, nylon fiber, polypropylene fiber etc. Also used for whitening and brightening polypropylene plastic, hard PVC, ABS, EVA polystyrene, polycarbonate. It is also used for polymer processing. The aim was to assess whether the PBT criterion within Annex XIII was fulfilled for2,2'-(ethene-1,2-diyldi-4,1-phenylene)bis(1,3-benzoxazole). 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 does not fulfil the P criterion within Annex XIII based on the assessment that here follows:

 

Biotic degradation

42-days Closed Bottle test following the OECD guideline 301 D to determine the ready biodegradability of the test item 2,2'-(ethene-1,2-diyldi-4,1-phenylene)bis(1,3-benzoxazole) (CAS no. 1533 -45 -5). The study was performed at a temperature of 20°C. The test system included control, test item and reference item. Polyseed were used for this study. 1 polyseed capsule were added in 500 ml D.I water and then stirred for 1 hour for proper mixing and functioning of inoculum. This gave the bacterial count as 107 to 108 CFU/ml. At the regular interval microbial plating was also performed on agar to confirm the vitality and CFU count of microorganism. The concentration of test and reference item (Sodium Benzoate) chosen for both the study was 4 mg/L, while that of inoculum was 32 ml/l. OECD mineral medium was used for the study. ThOD (Theoretical oxygen demand) of test and reference item was determined by calculation. % degradation was calculated using the values of BOD and ThOD for test item and reference item. The % degradation of procedure control (reference item) was also calculated using BOD & ThOD and was determined to be 75.3%. Degradation of Sodium Benzoate exceeds 46.38% on 7 days & 61.44% on 14th day. The activity of the inoculum was thus verified and the test can be considered as valid. The BOD42 value of test chemical 2,2'-(ethene-1,2-diyldi-4,1-phenylene)bis(1,3-benzoxazole) was observed to be 0.62 mgO2/mg. ThOD was calculated as 2.31 mgO2/mg. Accordingly, the % degradation of the test item after 42 days of incubation at 20 ± 1°C according to Closed Bottle test was determined to be 26.83%. Based on the results, the test item, under the test conditions, was considered to be primary inherently biodegradable in nature.

 

Thus based on the available information of the test chemical 2,2'-(ethene-1,2-diyldi-4,1-phenylene)bis(1,3-benzoxazole), it has been concluded that chemical 2,2'-(ethene-1,2-diyldi-4,1-phenylene)bis(1,3-benzoxazole) is likely to be not persistent (not P) in nature.

 

Bioaccumulation assessment

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

 

The estimated BCF value from authoritative database was determined to be ranges from 7541 to 53940.68, respectively. 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 BCF value indicate the chemical to be Very bioaccumulative (vB), since only predicted data is available for the substance, it has been concluded thatchemical2,2'-(ethene-1,2-diyldi-4,1-phenylene)bis(1,3-benzoxazole)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

All of the available short-term eco-toxicity data for fish, invertebrates and algae for the substance indicates the LC50/EC50 value was determined to be ranges from > 0.645 to 2.391 mg/L, respectively. These value suggest that the substance is likely to be hazardous to Aquatic organisms at environmentally relevant concentrations and can be considered to be classified in ‘Aquatic Chronic Category 2’ as per the CLP regulation.

 

There are no available long-term toxicity evaluations forchemical2,2'-(ethene-1,2-diyldi-4,1-phenylene)bis(1,3-benzoxazole). 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 B criterion but does not fulfil the P and T criterion and has therefore not been classified as a PBT compound within Annex XIII.