Methyl methanesulphonate

Toxicity to aquatic algae and cyanobacteria

Link to relevant study record(s)

Reference

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Data is from peer reviewed journal

Justification for type of information:

Data is from peer reviewed journal

Qualifier:

according to guideline

Guideline:

other: as mentioned below

Principles of method if other than guideline:

Short term toxicity Chlamydomonas reinhardtii study was carried out for 60 mins.

GLP compliance:

not specified

Specific details on test material used for the study:

- Name of test material (as cited in study report): Methyl methanesulfonate
- Molecular formula (if other than submission substance): C2H6O3S
- Molecular weight (if other than submission substance): 110.1324 g/mol
- Smiles notation (if other than submission substance): COS(=O)(=O)C
- InChI: 1S/C2H6O3S/c1-5-6(2,3)4/h1-2H3
- Substance type: Organic
- Physical state: Liquid

Analytical monitoring:

not specified

Details on sampling:

- Concentrations: 1000, 2000 and 3000 mg/l (0.1, 0.2 and 0.3%) respectively.

Vehicle:

not specified

Details on test solutions:

No data available

Test organisms (species):

Chlamydomonas reinhardtii

Details on test organisms:

TEST ORGANISM
- Common name: Chlamydomonas reinhardtii.
- Source (laboratory, culture collection): The test organism was obtained from Liege (Belgium). A wild type strain of unicellular green alga C. reinhardtii was used for the study.
- Method of cultivation: Algal cells were treated with test chemical methyl methanesulfonate (0.1, 0.2 and 0.3%) for 60 mins in the dark and then plated on agar dishes supplemented with acetate. After 5 days of cultivation, survival was evaluated by a microscopic method that distinguished the algal cells having died due to cytotoxicity from the cells having died due to mutagenic (lethal mutations) effects of test chemical MMS.

Test type:

static

Water media type:

freshwater

Total exposure duration:

60 min

Post exposure observation period:

After 5 days of cultivation, survival of test organism was evaluated by a microscopic method.

Nominal and measured concentrations:

Nominal concentrations: 1000, 2000 and 3000 mg/l (0.1, 0.2 and 0.3%) respectively.

Details on test conditions:

TEST SYSTEM
- Test vessel: Test tubes, petri plates.

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : yes
- Determination of cell concentrations: After 5 days of cultivation, survival was evaluated by a microscopic method that distinguished the algal cells having died due to cytotoxicity from the cells having died due to mutagenic (lethal mutations) effects of test chemical MMS.

TEST CONCENTRATIONS
- Test concentrations: 1000, 2000 and 3000 mg/l (0.1, 0.2 and 0.3%) respectively.

Reference substance (positive control):

not specified

Key result

Duration:

60 min

Dose descriptor:

EC50

Effect conc.:

1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: Mortality

Reported statistics and error estimates:

For statistical analysis Student’s t-test was used.

Table: Percentage survival evaluated in algae C.reinhardtii after treatment with test chemical methyl methanesulfonate (MMS).

 

Test compound	Concentration	Survival (%)
Methyl methanesulfonate (MMS)	1000 mg/l (0.1%)	53.32%*
Methyl methanesulfonate (MMS)	2000 mg/l (0.2%)	27.71%*

Where, * =Significant difference in comparison with the negative control (DMSO,p < 0.01).

Validity criteria fulfilled:

not specified

Conclusions:

Short term toxicity Chlamydomonas reinhardtii study was carried out for 60 mins. Based on mortality of the test organism Chlamydomonas reinhardtii, the EC50 value for Methyl methanesulfonate was determined to be 1000 mg/l.

Executive summary:

Short term toxicity Chlamydomonas reinhardtii study was carried out for 60 mins. The test organism used for the study was unicellular green alga C. reinhardtii. Algal cells were treated with test chemical methyl methanesulfonate (0.1, 0.2 and 0.3%) for 60 mins in the dark and then plated on agar dishes supplemented with acetate. After 5 days of cultivation, survival was evaluated by a microscopic method that distinguished the algal cells having died due to cytotoxicity from the cells having died due to mutagenic (lethal mutations) effects of test chemical MMS. The test was performed under static conditions for 60 mins. For statistical analysis Student’s t-test was used. Based on mortality of the test organismChlamydomonas reinhardtii,the EC50 value was determined to be 1000 mg/l.

Thus based on the EC50 value, it can be concluded that the substance Methyl methanesulfonate can be considered as non-toxic to aquatic organisms and thus can be considered to be not classified as per the criteria of CLP regulation.

 

Description of key information

Short term toxicity Chlamydomonas reinhardtiistudy was carried out for 60 mins (Eva Miadokova et. al; 2010). The test organism used for the study was unicellular green alga C. reinhardtii. Algal cells were treated with test chemical methyl methanesulfonate (0.1, 0.2 and 0.3%) for 60 mins in the dark and then plated on agar dishes supplemented with acetate. After 5 days of cultivation, survival was evaluated by a microscopic method that distinguished the algal cells having died due to cytotoxicity from the cells having died due to mutagenic (lethal mutations) effects of test chemical MMS. The test was performed under static conditions for 60 mins. For statistical analysis Student’s t-test was used. Based on mortality of the test organism Chlamydomonas reinhardtii, the EC50 value was determined to be 1000 mg/l. Thus based on the EC50 value, it can be concluded that the substance Methyl methanesulfonate can be considered as non-toxic to aquatic organisms and thus can be considered to be not classified as per the criteria of CLP regulation.

 

Key value for chemical safety assessment

EC50 for freshwater algae:

1 000 mg/L

Additional information

Various key and supporting study for the target chemical Methyl methanesulfonate (CAS no. 66 -27 -3) were reviewed for the toxicity to aquatic algae and cyanobacteria end point which are summarized as below:

 

In a key study, short term toxicity Chlamydomonas reinhardtii study was carried out for 60 mins (Eva Miadokova et. al; 2010). The test organism used for the study was unicellular green alga C. reinhardtii. Algal cells were treated with test chemical methyl methanesulfonate (CAS no. 66-27-3) (0.1, 0.2 and 0.3%) for 60 mins in the dark and then plated on agar dishes supplemented with acetate. After 5 days of cultivation, survival was evaluated by a microscopic method that distinguished the algal cells having died due to cytotoxicity from the cells having died due to mutagenic (lethal mutations) effects of test chemical MMS. The test was performed under static conditions for 60 mins. For statistical analysis Student’s t-test was used. Based on mortality of the test organism Chlamydomonas reinhardtii,the EC50 value was determined to be 1000 mg/l.

 

In a supporting study from peer reviewed journal (NEOPLASMA, 2006), short term toxicity Chlamydomonas reinhardtii study was carried out for 30 mins. The test organism used for the study was unicellular green alga C. reinhardtii recombination-repair-deficient strain uvs10.The life stage of the test organism was log growth phase. Algal cells were cultivated with a 12-h photoperiod in a liquid medium supplemented with acetate for 3–4 d (log growth phase) at 25°C and harvested by centrifugation for 7 min at 3,000 rpm. Subsequently, algal cell suspensions were treated with test chemical methyl methanesulfonate (CAS no. 66-27-3) (0.1, 0.2 and 0.3%) for 30 mins in the dark. Survival was evaluated by microscopic method, assessing the number of living cells (colonies) and dead cells due to the cytotoxic and mutagenic (lethal mutations) effects of test substance. The test was performed under static conditions for 30 mins with a 12 hr photoperiod. In the assay, the differences between the groups were analyzed using the standardt-test for paired observations. Statistical analyses were performed using ISI <R> Software, Version 2.0. Based on mortality of the test organism Chlamydomonas reinhardtii, the EC50 value was determined to be 1000 mg/l.

 

Another supporting study of short term toxicity Chlamydomonas reinhardtii study was carried out for 30 mins (Eva Miadokova et. al; 2005). The test organism used for the study was unicellular green alga C. reinhardtii recombination-repair-deficient strain uvs10. Algal cells were treated with test chemical methyl methanesulfonate (MMS) (0.1 - 0.5%) for 30 mins in the dark, and then plated on agar dishes. Survival was evaluated by microscopic method,which enabled to distinguish algal cells died due to cytotoxic and due to genotoxic (lethal mutations) effect of MMS. The test was performed under static conditions for 30 mins. For statistic analysis Wilcoxon’s two sample test was used. Based on mortality of the test organism Chlamydomonas reinhardtii,the EC50 value was determined to be 1000 mg/l. Thus based on the EC50 value, it can be concluded that the substance Methyl methanesulfonate can be considered as non-toxic to aquatic organisms and thus can be considered to be not classified as per the criteria of CLP regulation.

 

In addition to all the above supporting data, another short term toxicity to Chlamydomonas reinhardtii study was carried out for 30 mins (B. G. Hawks and R. W. Lee, 1976). The test organism used for the study green alga C. reinhardtii. Test chemical conc. used for the study was 1321.56 mg/l (12mM) or 2643.12 mg/l (24 mM), respectively. The test was performed under static conditions for 30 mins. Treatment with chemical Methyl methanesulfonate (MMS) (CAS no. 66-27-3) was performed on cells from different stages of synchronous growth after they were harvested and resuspended in 0.03 M, pH 7.0, phosphate buffer at a cell density of 107cells/ml. Mutagenesis was performed for 30 mins in darkness at 25°Cwith moderate shaking. Control samples not treated with MMS was prepared in a similar manner. Cell survival was determined during the period of 30 mins. Based on the percentage of cell survival of the test organism Chlamydomonas reinhardtii, the EC90 value for Methyl methanesulfonate was determined to be 1321.56 mg/l.

 

In a prediction done using the EPI Suite ECOSAR version 1.10 (EPI suite, 2017), the short term toxicity on green algae was predicted for test substance Methyl methanesulfonate (CAS no. 66 -27 -3). The 96 hours EC50 was estimated to be 2646.470 mg/L on algae for substance methyl methanesulphonate with growth inhibition effects.

 

Thus, based on the overall reported results for target chemical Methyl methanesulfonate (from peer reviewed journals), it can be concluded that the test substance Methyl methanesulfonate can be considered as non-toxic to aquatic environment and thus can be considered to be not classified as per the CLP classification criteria.