Dimethyl sulphone

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

14.12.2016 - 16.12.2016

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

Experimental test result using OECD guidelines.

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Principles of method if other than guideline:

Determination of the inhibition of the mobility of Daphnids was carried out with the substance according to OECD Guideline 202.

GLP compliance:

no

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
The solution 100.0 mg/L was prepared by dissolving white powder in reconstituted water.

- Controls: Reconstituted water as specified in OECD 202, used as a control and for sample dilution.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Water flea
- Strain/clone: Straus
- Source: Own breeding at University of Chemistry and Technology, Prague
- Age: Young daphnids, aged less than 24 hours used at the start of the test and they should not be first brood progeny.
- Feeding during test : Without feeding

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Remarks on exposure duration:

± 1 h

Test temperature:

20 °C ± 1 °C

pH:

Sample : pH = 7.7 did not change during the test,
Control: pH = 7.7 changed to pH = 7.6 during the test.

Dissolved oxygen:

Higher than 7.9 mg/L both in the control and the sample.

Details on test conditions:

TEST SYSTEM
- Test vessel: 50 ml glass vessel
- Material, size, headspace, fill volume: 25 ml
- No. of organisms per vessel: 5 pieces
- No. of vessels per concentration (replicates): 4


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Natural water (surface or ground water), reconstituted water or dechlorinated tap water are acceptable as culturing and dilution water if D. magna survives in it for the duration of the culturing, acclimation and testing without showing signs of stress. Waters in the range pH 6 to pH 9, with hardness between 140 mg/l and 275 mg/l (as CaCO3) are recommended.As an example, the preparation of dilution water meeting the requirements is described below.Dissolve known quantities of reagents in water. The dilution water prepared shall have a pH of 7.8 ± 0.5, a hardness of (225 ± 50) mg/l (expressed as CaCO3), a molar Ca + Mg ratio close to 4 + 1 and a dissolved oxygen concentration above 7 mg/l.

Prepare the solutions specified below:
- Calcium chloride solution: Dissolve 117.6 g of calcium chloride dihydrate (CaCl2.2H2O) in water (4.2) and make up to 1 l with water (4.2).
- Magnesium sulfate solution: Dissolve 49.3 g of magnesium sulfate heptahydrate (MgSO4.7H2O) in water (4.2) and make up to 1 l with water (4.2).
- Sodium bicarbonate solution: Dissolve 25.9 g of sodium bicarbonate (NaHCO3) in water (4.2) and make up to 1 l with water (4.2).
- Potassium chloride solution: Dissolve 2.3 g of potassium chloride (KCI) in water (4.2) and make up to 1 l with water (4.2).

Mixing
Mix 2.5 ml of each of the four solutions and make up to 1 l with water.
The dilution water shall be aerated until the dissolved oxygen concentration has reached saturation and the pH has stabilized. If necessary, adjust the pH to 7.8 ± 0.5 by adding sodium hydroxide (NaOH) solution or hydrochloric acid (HCI). The dilution water prepared in this way shall not be further aerated before use.

- Sodium hydroxide solution, e.g. [NaOH] : 1 mol/l.
- Hydrochloric acid, e.g. [HCl] : 1 mol/l.

OTHER TEST CONDITIONS
- Adjustment of pH: Without adjustment
- Photoperiod: No - Darkness

EFFECT PARAMETERS MEASURED (with observation intervals if applicable): Inhibition % was calculated.

Reference substance (positive control):

yes

Remarks:

Potassium dichromate (K2Cr2O7)

Key result

Duration:

48 h

Dose descriptor:

other: IC5%

Effect conc.:

100 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: Other details not known

Details on results:

After the exposure of test chemical for 48 hrs, only 5% inhibition were observed at 100 mg/l. Thus EC50 was consider to be > 100 mg/l.

Results with reference substance (positive control):

- Results with reference substance valid
- 24h EC50 = 0.79 mg/L K2Cr2O7

Validity criteria fulfilled:

yes

Conclusions:

After the exposure of test chemical with daphnia magna for 48 hrs, only 5% inhibition were observed at 100 mg/l. Thus EC50 was consider to be > 100 mg/l on the basis of mobility inhibition effects in a 48 hours of study.

Executive summary:

Determination of the inhibition of the mobility of daphnids was carried out with the substance according to OECD Guideline 202. A limit test at sample concentration of 100 mg/L was performed. Effects on immobilisation were observed for 48 hours. The test was performed under static conditions in a fresh water system at a temperature of 20 °C± 1 °C. EC50 was calculated. After the exposure of test chemical with daphnia magna for 48 hrs, only 5% inhibition were observed at 100 mg/l. Thus EC50 was consider to be > 100 mg/l on the basis of mobility inhibition effects in a 48 hours of study. Based on this EC50 value and after comparing with CLP criteria for aquatic classification of the substance it is concluded that the substance does not exhibit short term toxicity to aquatic invertebrate (Daphnia Magna) and thus not classified as per the CLP classification criteria.

Description of key information

Determination of the inhibition of the mobility of daphnids was carried out with the substance according to OECD Guideline 202. A limit test at sample concentration of 100 mg/L was performed. Effects on immobilisation were observed for 48 hours. The test was performed under static conditions in a fresh water system at a temperature of 20 °C± 1 °C. EC50 was calculated. After the exposure of test chemical with daphnia magna for 48 hrs, only 5% inhibition were observed at 100 mg/l. Thus EC50 was consider to be > 100 mg/l on the basis of mobility inhibition effects in a 48 hours of study. Based on this EC50 value and after comparing with CLP criteria for aquatic classification of the substance it is concluded that the substance does not exhibit short term toxicity to aquatic invertebrate (Daphnia Magna) and thus not classified as per the CLP classification criteria.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

100 mg/L

Additional information

Based on the effects observation on the mobility of aquatic invertebrate by the chemical exposure, studies were reviewed from various experimental sources for test chemical were studied and mention as below:

In the first key study from experimental report determination of the inhibition of the mobility of daphnids was carried out with the substance according to OECD Guideline 202. A limit test at sample concentration of 100 mg/L was performed. Effects on immobilisation were observed for 48 hours. The test was performed under static conditions in a fresh water system at a temperature of 20 °C± 1 °C. EC50 was calculated. After the exposure of test chemical with daphnia magna for 48 hrs, only 5% inhibition were observed at 100 mg/l. Thus EC50 was consider to be > 100 mg/l on the basis of mobility inhibition effects in a 48 hours of study. Based on this EC50 value and after comparing with CLP criteria for aquatic classification of the substance it is concluded that the substance does not exhibit short term toxicity to aquatic invertebrate (Daphnia Magna) and thus not classified as per the CLP classification criteria.

First experimental study was supported by the second study from secondary source. A 96 hr static toxicity test was conducted to determine the toxic effect of test chemical on mysid shrimp (Mysidopsis bahia). The test was conducted in 1-L uncovered glass beakers, each of which contained 900ml of test chemical and control seawater. There was no aeration. Dissolved oxygen (DO) concentrations were >97% of saturation at initiation of the test. Shrimp were not fed during the test. Based on the results of range finding study, shrimp were tested at nominal concentration of 1000ppm. The test concentration was prepared by adding 0.9184 grams of test chemical in directly to seawater. Exposure to test chemical did not appear to adversely affect mysid shrimp. After 72 hours of exposure, no mortality had occurred in 1,000 ppm and control. After 96 hours of exposure, mortality was 10% among mysids exposed to 1,000 ppm and among control mysids 5% mortality were observed. Therefore, the LC10 value for test chemical is considered to be 1000 mg/l on mysid shrimp (Mysidopsis bahia). Based on the mortality effect, chemical consider to be nontoxic and not classified as per the CLP classification criteria.

 

Thus based on the both studies from experimental report and secondary source, it was concluded that the chemical was nontoxic and not classified as per the CLP classification criteria.