Methyl methanesulphonate

PBT assessment

PBT assessment: overall result

PBT status:

the substance is not PBT / vPvB

Justification:

Classification of Methyl methanesulphonate for effects in the environment:

 

The chemical Methyl methanesulphonate (CAS no. 66-27-3) is used for chemical synthesis as wellas an laboratory chemical. The aim was to assess whether the PBT criterion within Annex XIII was fulfilled for Methyl methanesulphonate. 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:

 

Environmental fate

According to the fugacity model levels III, the most likely environmental fate for this test chemical is soil (i.e.estimated to 51.3%).In soil, Methyl methanesulphonatewas expected to have rapid mobility based upon an estimated Log KOC in the range 0-1.06. Thehalf-life in soil (30 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, 40.7% of the chemical will partition into water according to the Mackay fugacity model level III in EPI suite version 4.1 (2017). The half-life (15 days estimated by EPI suite) indicates that the substance is not persistent in water and 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 1% when estimated by EPI Suite version 4.1).

 

Hence it has been concluded that Methyl methanesulphonate 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 estimated BCF value from various databases was determined to be in the range 1 – 3.2 and theestimatedoctanol water partition coefficient of the test chemical is -0.66 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 classified for carcinogenicity, mutagenicity and reprotoxicity in category 2 as per the CLP regulation.

Further, there is evidence of chronic toxicity by oral and inhalative route on repeated exposure.

 

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 2.0 - 9800 mg/L. These conditions suggest that the substance is likely to be hazardous to Aquatic organisms at environmentally relevant concentrations.

 

Long-term toxicity evaluations in fish are available for Methyl methanesulphonate. The Long-term EC50 was determined to be 0.2 mg/L and LOEC was determined to be 0.11 mg/L. Based on these values, the substance can be considered to be classified in Aquatic chronic category 2 as per the CLP regulation.

 

By speculation, long-term NOEC for aquatic organisms were expected for the substance at concentration below 0.01 mg/L based on the data mentioned above and hence the chemical was 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 does not fulfil the P and B criterion but fulfils the T criterion and has therefore not been classified as a PBT compound within Annex XIII.