3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarbonyl chloride

PBT assessment

PBT assessment: overall result

PBT status:

the substance is not PBT / vPvB

Justification:

Classification of 3-(2, 2-dichloroethenyl)-2, 2-dimethylcyclopropane-1-carbonyl chloride for effects in the environment:

 

The chemical 3-(2, 2-dichloroethenyl)-2, 2-dimethylcyclopropane-1-carbonyl chloride (CAS no. 52314-67-7) is used as an intermediate in chemical synthesis and pharmaceutical industry. The aim was to assess whether the PBT criterion within Annex XIII was fulfilled for the substance 3-(2, 2-dichloroethenyl)-2, 2-dimethylcyclopropane-1-carbonyl chloride. 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 3.3 with logKow as the primary descriptor, percentage biodegradability of test chemical 3-(2,2-dichloroethenyl)-2,2-dimethylcyclopropane-1-carbonyl chloride (CAS No. 52314-67-7) was estimated. Test substance undergoes 14.89% degradation by BOD in 28 days. Thus, based on percentage degradation, the test chemical 3-(2,2-dichloroethenyl)-2,2- dimethylcyclopropane-1-carbonyl chloride 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 compound 3 -(2,2 -dichloroethenyl)-2,2 -dimethylcyclopropane-1 -carbonyl chloride(CAS No. 52314-67-7) 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 3-(2,2-dichloroethenyl)-2,2-dimethylcyclopropane-1-carbonyl chloride is expected to be not readily biodegradable.

 

Experimental study on read across substances (CAS: 4390-04-9 and 79-01-6) also indicate the substances to be 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 55.7%). In soil, 3-(2, 2-dichloroethenyl)-2, 2-dimethylcyclopropane-1-carbonyl chloride was expected to have slow to moderate mobility based upon an estimated Log KOCin the range 1.79 – 3.2.Thehalf-life in soil (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.

 

If released in to the environment, 33.5 % and 0.168% of the chemical will partition into water and sediment, respectively according to the Mackay fugacity model level III in EPI suite version 4.1 (2017). Moreover, the half-life (60 days in water and 541.66 days in sediment as estimated by EPI suite) indicates that the chemical is persistent in both the compartments.

However, Fugacity modelling shows that sediment is not an important environmental fate (less than 1% when estimated by EPI Suite version 4.1) and hence the substance can be considered as not persistent in sediment.

 

Hence it has been concluded that the substance 3-(2, 2-dichloroethenyl)-2, 2-dimethylcyclopropane-1-carbonyl chloride is likely to be persistent in nature.  

 

Bioaccumulation assessment

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

 

Theestimated BCF value from various databases was determined to be in the range 22.7 – 280.12 and the estimatedoctanol water partition coefficient of the test chemical is 2.82 which is less than the threshold of 4.5. 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 fulfils 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 estimation for invertebrates and algae for the substance indicates the LC50/EC50 value to be in the range 0.70 – 0.79 mg/L. These value suggest that the substance is likely to be hazardous at environmentally relevant concentrations and can be classified in Aquatic acute category 1 as per the CLP regulation.

 

There are no available long-term toxicity evaluations for 3-(2, 2-dichloroethenyl)-2, 2-dimethylcyclopropane-1-carbonyl chloride. By speculation, long-term NOEC for aquatic organisms can be expected for the substance at concentration below 0.01 mg/L based on the data mentioned above.

 

The chemical was therefore 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 T criterion but does not fulfil the B criterion and has therefore not been classified as a PBT compound within Annex XIII.