3-(1H-benzimidazol-2-yl)-7-(diethylamino)-2-benzopyrone

PBT assessment

PBT assessment: overall result

PBT status:

the substance is not PBT / vPvB

Justification:

Classification of 3-(1H-benzimidazol-2-yl)-7-(diethylamino)-2-benzopyrone for effects in the environment

3-(1H-benzimidazol-2-yl)-7-(diethylamino)-2-benzopyrone (CAS no. 27425-55-4) has a wide variety of uses such as: agrochemical intermediate, intermediate for chemical synthesis, pharma intermediate, dyestuff intermediate and as a laboratory agent. The aim of the PBT assessment was to evaluate whether this chemical fulfils the PBT criterion within Annex XIII. The PBT assessment were based on toxicological information in conjunction with standardized environmental fate- and bioaccumulation 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

Biodegradation in water ability was predicted for the test compound 3 -(1H-benzimidazol-2 -yl)-7 -(diethylamino)-2 -benzopyrone (CAS no. 27425 -55 -4) using the SSS QSAR prediction model (2016). The inherent biodegradability of the test substance 3-(1H-benzimidazol-2-yl)-7-(diethylamino)-2-benzopyrone was estimated as 84.56% by using DOC removal parameter. This result indicates that 3-(1H-benzimidazol-2-yl)-7-(diethylamino)-2-benzopyrone was estimated to be readily biodegradable in water.

 

Environmental fate

According to the fugacity model levels III, the most likely environmental fate for this test chemical is soil (i.e.estimated to 76.9%). The Koc-value was estimated to 13000 at 25ºC (KOCWIN program) indicating negligible mobility and very high adsorption potential.

The tested chemical is therefore not expected to leach from soil. The half-life (75 days estimated by EPI suite) indicates that the exposure risk to soil-dwelling organism should therefore be moderate to low.

If released in to the environment, only 13.2% of the chemical will partition into water whereas 9.92% will partition into sediment according to the Mackay fugacity model level III in EPI suite version 4.1 (2016). The estimated half-life (37.5 days in water and 337.5 days in sediment estimated by EPI suite) indicates that substance is likely to be persistent in sediment and likely to be persistent in sediment.

 

If released in to the environment, 13.2 % of the chemical will partition into water according to the Mackay fugacity model level III in EPI suite version 4.1 (2016). However, the half-life (37.5 days estimated by EPI suite) indicates that the exposure risk to aquatic animals is moderate to low.

Moreover, its persistent characteristic is only observed in the sediment compartment but Fugacity modelling shows that sediment is not an important environmental fate (less than 10% when estimated by EPI Suite version 4.1). Hence it has been concluded that 3-(1H-benzimidazol-2-yl)-7-(diethylamino)-2-benzopyrone is not persistent in nature.  

 

Bioaccumulation assessment

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

 

The BCF value is estimated to be 124.1 L/kg and the log Kow value is approx. 3.68 at 25ºC (both calculated by EPI suite version 4.1, 2016). 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 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

The available short-term eco-toxicity estimation for fish, invertebrates and algae for CAS 27425-55-4 indicates the LC50/EC50 value to be 8.519 mg/L, 32.3 mg/L and 16 mg/L respectively. Although these values suggest classification of the substance in Aquatic Chronic category 2, since the substance is estimated to be readily biodegradable it is classified as non-hazardous for aquatic toxicity as per the CLP criteria. Thus, classification for aquatic toxicity will not be applicable for all of the tropic levels on the basis of criteria set out in Annex XIII and the same is based on the above mentioned estimation studies.

 

Conclusion

Based on critical, independent and collective evaluation of information summarized herein, the tested chemical does not fulfil the P, B and T criterion and has therefore not been classified as a PBT compound within Annex XIII.