Dimethyl sulphate

Short-term toxicity to aquatic invertebrates

Administrative data

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

21.08.1990 to 23.08.1990

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Acceptable, well-documented publication/study report which meets basic scientific principles. No determination of the test substance concentration, therefore no method validation included in the study.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2008

Report date:

2008

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

yes

Remarks:

No determination of the test substance concentration, therefore no method validation included in the study.

GLP compliance:

not specified

Remarks:

The test was performed in 1990 by Stuhlfauth. Only the report was newly generated at the mentioned date given above, form archived laboratory manuscripts.

Test material

Test material information

Constituent 1

Reference substance name:

Dimethyl sulphate

EC Number:

201-058-1

EC Name:

Dimethyl sulphate

Cas Number:

77-78-1

Molecular formula:

C2H6O4S

IUPAC Name:

dimethyl sulfate

Details on test material:

- Name of test material (as cited in study report): Dimethyl sulphate
- Physical state: liquid
- no further significant data stated

Specific details on test material used for the study:

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

Sampling and analysis

Analytical monitoring:

no

Details on sampling:

no data

Test solutions

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Stock solution: 2048 mg DMS/L
- no further significant data stated

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Number of animals: 20 per test concentration (devided into 2 groups of 10)
- Common name: Daphnia
- Age at study initiation (mean and range, SD): 3- 24 h
- Method of breeding: Adult animals were cultivated in glass vessels (volume: 4 litres). The medium was changed once a week. Twice daily the animals were fed with algae (Scenedesmus supspicatus).
- control group: animals in medium without test substance
- no further significant data stated

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Post exposure observation period:

no

Test conditions

Hardness:

no data

Test temperature:

21 °C

pH:

no data

Dissolved oxygen:

after 48 h: 9.5 mg/L

Salinity:

no data

Nominal and measured concentrations:

nominal concentrations: 0, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024 mg/L; separation factor 2

Details on test conditions:

TEST SYSTEM
- test volume: 50 ml
- Test vessel:
- Material, size, headspace, fill volume: 100 ml glass vessel
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 2


TEST MEDIUM / WATER PARAMETERS
- Medium: synthetic water according to DIN 38 412 Part 11
- Source/preparation of dilution water: synthetic water

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod:dark chamber

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- determination of mobility after 24 and 48 hours


TEST CONCENTRATIONS
- Spacing factor for test concentrations:
- Justification for using less concentrations than requested by guideline:
- Range finding study: yes
- Results used to determine the conditions for the definitive study: With the indicated test data the EC50 of Dimethylsulfate TTR (tested batch) to Daphnia magna under the conditions of the test was estimated to be 17 mg/l based on nominal values. No immobilization was observed at the two lowest test concentrations of 2 mg/l and 4 mg/l.
- no further details stated

Reference substance (positive control):

yes

Remarks:

potassium dichromate, 0.9 and 1.9 mg/l, 2 replicates

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

17 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 14-21 mg/L

Effect concentrations 2

Duration:

48 h

Dose descriptor:

EC0

Effect conc.:

8 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Effect concentrations 3

Duration:

48 h

Dose descriptor:

EC100

Effect conc.:

64 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Effect concentrations 4

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

53 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

mobility

Remarks on result:

other: 41-68 mg/L

Effect concentrations 5

Duration:

24 h

Dose descriptor:

EC0

Effect conc.:

4 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Effect concentrations 6

Duration:

24 h

Dose descriptor:

EC100

Effect conc.:

128 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

Mortality of control: below 10 % immobilised

Results with reference substance (positive control):

Mortality (Potassium dichromate)
EC50: after 24 h was between 0.9 and 1.9 mg/L
no further details stated

Reported statistics and error estimates:

Probit analysis

Any other information on results incl. tables

Immobilization rates of Daphnia magna exposed to Dimethylsulfate TTR over a period of 24 and 48 hours

Nominal test concentration [mg/l]	Replicate	Number of daphnids exposed	Number of immobilized daphnids		Percentage of immobilized daphnids		Mean [%]
			24 h	48 h	24 h	48 h	24 h	48 h
Control	1	10	0	0	0	0	0	5
	2	10	0	1	0	10
2	1	10	0	0	0	0	0	0
	2	10	0	0	0	0
4	1	10	0	0	0	0	0	0
	2	10	0	0	0	0
8	1	10	0	0	0	0	5	0
	2	10	1	0	10	0
16	1	10	2	9	20	90	15	50
	2	10	1	1	10	10
32	1	10	2	9	20	90	15	90
	2	10	1	9	10	90
64	1	10	3	10	30	100	35	100
	2	10	4	10	40	100
128	1	10	10	10	100	100	100	100
	2	10	10	10	100	100
256	1	10	10	10	100	100	100	100
	2	10	10	10	100	100
512	1	10	10	10	100	100	100	100
	2	10	10	10	100	100
1024	1	10	10	10	100	100	100	100
	2	10	10	10	100	100

Table 2:       Number and percentage of immobilization of Daphnia magna after 24 hours exposed to Potassium dichromate

Nominal test concen­tration [mg/l]	Replicate	Number of daphnids exposed	Number of immobilized daphnids		Percentage of immobilized daphnids		Mean [%]
0.9	1	10	1	5	10	50	10	55
	2	10	1	6	10	60
1.9	1	10	10	10	100	100	100	100
	2	10	10	10	100	100

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The EC50 was determined at 17 mg test substance/L after 48h of exposure in freshwater. The test was performed with daphnia magna. No analytical determination was performed, the values are based on the nominal concentration. Due to the fact that DMS hydrolyses very fast (DT50 <1d) in water to monomethyl sulfate and methanol, the immobilisation observed is predominantly based on the hydrolysis products.