Methanesulphonyl chloride

Toxicity to aquatic algae and cyanobacteria

Administrative data

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

from 2007-09-28 to 2009-08-03

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: 1a: GLP guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2009

Report date:

2009

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Methanesulphonyl chloride

EC Number:

204-706-1

EC Name:

Methanesulphonyl chloride

Cas Number:

124-63-0

Molecular formula:

CH3ClO2S

IUPAC Name:

methanesulfonyl chloride

Details on test material:

- Name of test material: Methanesulfonyl chloride
- Lot/batch No.: MSC B14GPD/Arkema
- Purity: > 99.9%
- Date of receipt: 2007-03-15
- Appearance: colourless or yellow liquid
- Water solubility: 1100 mg/L at 20 °C
- Density at 20°C: 1474 kg/m3
- Dissolved in water

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
not relevant

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

- Sample storage before analysis: no storage
- Samples treatment: direct analysis

Test solutions

Vehicle:

no

Details on test solutions:

PREPARATION
A stock solution of the test item diluted in water was prepared three days before the beginning of the test (time 0) by mixing 100 mg (67.7µl) of MSC in 1 L of dilution water for preliminary and definitive test.

Test organisms

Test organisms (species):

Raphidocelis subcapitata (previous names: Pseudokirchneriella subcapitata, Selenastrum capricornutum)

Details on test organisms:

TEST ORGANISM
- Common name: Pseudokirchnerella subcapitata, CCAP 278/4 stock (previously named Raphidocelis subcapitata and Selenastrum capricornutum)
- Source: Culture Centre of Algae and Protozoa (Ambleside, UK).

ACCLIMATION
- Two flasks, each containing approximately 100 mL of axenic stock culture of algae are incubated at 23 ± 1 °C under lighting (photoperiod: 16 hours of illumination, 8 hours of darkness), slowly continuously shaken. These stock cultures are renewed every week, using two new cultures.
The quality of the stock culture was verified for the absence of micro-organisms and deformed cells under microscopic observation before use.
Three days before the beginning of the study two pre-cultures were prepared by inoculating each stock suspension of algae (5 mL) into sterile dilution water (500 mL). The pre-cultures were incubated under the same conditions as those used for the stock cultures. Only one of the two pre-cultures was used to inoculate the test flasks; the second one was to be used only if the first one was damaged.
- At the beginning of the test, the cell concentration of the pre-culture was determined. The result was used to calculate the volume to be introduced into each test flask in order to get an initial cell concentration of 10^4 cells/mL.
- The cell density of the pre-culture was about 1.441 x 10^6 cells/ml for the definitive test.

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Test conditions

Hardness:

no data

Test temperature:

23 ± 1°C

pH:

At the beginning of the test, from 7.08 to 3.38 (concentration 100 mg/L).
At the end of the test, from 8.83 to 3.37 (concentration 100 mg/L).
pH is considerably lowered for the higher nominal concentrations of the test item due to the hydrolysis of the substance into MSA.

Dissolved oxygen:

from 9.0 to 10.0 mg/L O2

Salinity:

no data

Nominal and measured concentrations:

Nominal concentrations: 10 - 15.84 - 25 - 40 - 63.10 and 100 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: 120 mL glass bottles stoppered with cellulose bungs (filling volume: 50 mL), placed in a phytoculture cabinet.
- No. of vessels per concentration (replicates): 3
- No. of vessels per vehicle control (replicates): 6

OTHER TEST CONDITIONS
- Flasks were continuously shaken with a rotation at 20 rpm
- Illumination: 8 fluorescent tubes between 6,000 and 10,000 lux

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 2.2
- Range finding study
- Test concentrations: 100, 50, 10, 5, 1, 0.1 mg/L

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

32 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 2

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

32 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Details on results:

Solutions were found to be clear, colourless over the period of the test. No precipitation was observed at the end of the test.
Microscopic observation confirmed that the algae appeared normal at the end of the test.

Results with reference substance (positive control):

ErC50 and EbC50 obtained on 27/09/2007 were respectively 1.20 mg/L and 0.46 mg/L.

Reported statistics and error estimates:

The growth inhibition data are analyzed using an Excel program. It was designed to calculate the EC50 value and the 95% confidence interval. Probit analysis is generally used to calculate the 24, 48 and 72-hour EC50 values.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Remarks:

See conclusions

Conclusions:

Quality criteria:
- The biomass in the control cultures has increased exponentially by a factor of at least 16 within the 72-hour test period. This corresponds to a specific growth rate of 0.92 per day.
- The mean coefficient of variation for section-by-section specific growth rates (days 0-1, 1-2 and 2-3, for 72-hour tests) in the control cultures did not exceed 35%. This criterion applies to the mean value of coefficients of variation calculated for replicate control cultures.
- The coefficient of variation of average specific growth rates during the whole test period in replicate control cultures did not exceed 7%.

Executive summary:

Toxicity of Methanesulfonyl chloride to Pseudokirchnerella subcapitata has been investigated through OECD Guideline 201.

Pseudokirchnerella subcapitata were exposed for 72 hours to an aqueous solution of Methanesulfonyl chloride at different nominal concentrations of 10 - 15.84 - 25 - 40 - 63.10 and 100 mg/L.

ErC 50 - 72h determined is of 32 mg/L and EbC50 - 72h is of 32 mg/L too.

The quality criteria were fulfilled.