Benzyl butyrate

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:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

Experimental test result performed using standard test guideline.

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

GLP compliance:

no

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

The stock solution 100 mg/l was prepared in reconstituted water. Test solutions of required concentrationas were prepared by mixing the stock solution of the test sample with reconstituted test water.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Water flea
- Strain: Straus
- Source: Own breeding at University of Chemistry and Technology, Prague
- Age at study initiation (mean and range, SD): The animals used for the test shall be less than 24 h old and should not be first brood progeny
- Feeding during test: No feeding

ACCLIMATION - No data available

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Remarks on exposure duration:

± 1 hr

Test temperature:

20±1°C

pH:

Test: 7.7 (no change during test)
Control: 7.8 (Change to 7.6 during test)

Dissolved oxygen:

higher than 7.8 mg/L at the end of test

Nominal and measured concentrations:

Nominal concentration: 0, 2.5, 5, 10, 20, 40 mg/l, respectively

Details on test conditions:

TEST SYSTEM
- Test vessel: 50 ml glass vessel
- fill volume: 25 ml
- No. of organisms per vessel: 5
- 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.

Reference substance:
Dissolve 600 mg of potassium dichromate (K2Cr2O7) in water and make up to 1 l with water (4.2).

OTHER TEST CONDITIONS
- Adjustment of pH: no adjustment done
- Photoperiod: No - Darkness
- Light intensity:

CALCULATION:
EC50 was calculated using non linear regression by the software Prism 4.0

Reference substance (positive control):

yes

Remarks:

Potassium dichromate (K2Cr2O7)

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

16.6 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 95 % CI was 14.7-18.7 mg/l

Results with reference substance (positive control):

- Results with reference substance valid
- EC50: 0.79 mg/L (24 hours)

Reported statistics and error estimates:

EC50 was calculated using non linear regression by the software Prism 4.0

Validity criteria fulfilled:

yes

Conclusions:

Based on the immobilisation of Daphnia magna due to the exposure of test chemical for 48 hours, the EC50 value was determine to be 16.6 mg/l.

Executive summary:

An acute immobilisation test was conducted for 48 hrs for assessing the short term toxicity of test chemical to aquatic invertebrate. Study was performed according to the OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test). Daphnia magna was used as a test organism. The stock solution 100 mg/l was prepared in reconstituted water. 0, 2.5, 5, 10, 20, 40 mg/l nominal concentrations were used in the study. 5 daphnids per concentration were used in the study. Effects on immobilisation were observed for 48 hours and conducted under the static system. With the test substance one positive control Potassium dichromate (K2Cr2O7) was also run simultaneously. Observations including immobility, pH, Temperature, dissolved oxygen content were recorded in the interval of 24 and 48 hours. After the exposure of chemical, effect concentration EC50 was calculated using nonlinear regression by the software Prism 4.0. Based on the immobilisation of Daphnia magna due to the exposure of test chemical for 48 hours, the EC50 value was determine to be 16.6 mg/l. EC50 value indicates that the substance is likely to be hazardous to aquatic invertebrates and can be classified in aquatic chronic 3 category as per the CLP criteria. As the test chemical was readily biodegradable in water, thus on the basis of degradation criteria, test chemical consider to be nontoxic and not classified as per the CLP classification criteria.

Description of key information

An acute immobilisation test was conducted for 48 hrs for assessing the short-term toxicity of test chemical to aquatic invertebrate. Study was performed according to the OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test). Daphnia magna was used as a test organism. The stock solution 100 mg/l was prepared in reconstituted water. 0, 2.5, 5, 10, 20, 40 mg/l nominal concentrations were used in the study. 5 daphnids per concentration were used in the study. Effects on immobilisation were observed for 48 hours and conducted under the static system. With the test substance one positive control Potassium dichromate (K2Cr2O7) was also run simultaneously. Observations including immobility, pH, Temperature, dissolved oxygen content were recorded in the interval of 24 and 48 hours. After the exposure of chemical, effect concentration EC50 was calculated using nonlinear regression by the software Prism 4.0. Based on the immobilisation of Daphnia magna due to the exposure of test chemical for 48 hours, the EC50 value was determine to be 16.6 mg/l. EC50 value indicates that the substance is likely to be hazardous to aquatic invertebrates and can be classified in aquatic chronic 3 category as per the CLP criteria. As the test chemical was readily biodegradable in water, thus on the basis of degradation criteria, test chemical considers to be nontoxic and not classified as per the CLP classification criteria.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

16.6 mg/L

Additional information

Following different studies includes experimental study for the test chemical and read-across analogues which is extracted by using mechanistic approach and functionally and structurally similar to the target chemical to observe the short-term toxicity of test chemical to aquatic invertebrates.

 

An acute immobilisation test was conducted for 48 hrs for assessing the short-term toxicity of test chemical to aquatic invertebrate. Study was performed according to the OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test). Daphnia magna was used as a test organism. The stock solution 100 mg/l was prepared in reconstituted water. 0, 2.5, 5, 10, 20, 40 mg/l nominal concentrations were used in the study. 5 daphnids per concentration were used in the study. Effects on immobilisation were observed for 48 hours and conducted under the static system. With the test substance one positive control Potassium dichromate (K2Cr2O7) was also run simultaneously. Observations including immobility, pH, Temperature, dissolved oxygen content were recorded in the interval of 24 and 48 hours. After the exposure of chemical, effect concentration EC50 was calculated using nonlinear regression by the software Prism 4.0. Based on the immobilisation of Daphnia magna due to the exposure of test chemical for 48 hours, the EC50 value was determine to be 16.6 mg/l. EC50 value indicates that the substance is likely to be hazardous to aquatic invertebrates and can be classified in aquatic chronic 3 category as per the CLP criteria. As the test chemical was readily biodegradable in water, thus on the basis of degradation criteria, test chemical considers to be nontoxic and not classified as per the CLP classification criteria.

 

First study further supported by the second study from experimental source. An short term immobilisation test was conducted for 48 hrs for assessing the short term toxicity of test chemical to aquatic invertebrate. Study was performed according to the OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test). The stock solution 100.0 mg/l was prepared in reconstituted water. The test solutions of required concentrations were prepared by mixing the stock solution of the test sample in reconstituted water. 2, 4 ,8,16, 32, 64 mg/l, respectively nominal test concentrations were prepared. Effects on immobilisation were observed for 48 hours and conducted under the static system. With the test substance one positive control Potassium dichromate (K2Cr2O7) was also run simultaneously. After the exposure of chemical, effect concentration EC50 was calculated using nonlinear regression by the software Prism 4.0. Based on the immobilisation of Daphnia magna due to the exposure of test chemical for 48 hours, the EC50 value was determine to be 15.1 mg/L with 95% CI of 10.5-21.5 mg/l. EC50 value indicates that the substance is likely to be hazardous to aquatic invertebrates and can be classified in aquatic chronic 3 category as per the CLP criteria. But as the chemical was readily biodegradable in water and degrade faster, thus chemical can be considered to be nontoxic and not classified as per the CLP classification criteria.

 

Similar study was to assess the short-term toxicity of test chemical to aquatic invertebrate. Study was performed according to the OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test). Daphnia magna was used a test organism. The animals used for the test was Daphnia magna, which should be less than 24 h old and should not be of first brood progeny. The stock solution 100 g/L was prepared in acetone. Test solutions of required concentrations were prepared by mixing the stock solution of the test sample with reconstituted test water. 0, 0, 5, 10, 20, 40 and 80 mg/L concentrations were used in the study. Effects on immobilisation were observed for 48 hours and conducted under the static system. With the test substance one positive control Potassium dichromate (K2Cr2O7) was also run simultaneously. After the exposure of chemical, effect concentration EC50 was calculated using nonlinear regression by the software Prism 4.0. The median effective concentration (EC50) value of the test substance on Daphnia magna was determined to be 60.7 mg/L on the basis of immobilisation effects in a 48-hour study. Based on the EC50 value, substance consider likely to be hazardous to aquatic invertebrate Daphnia magna and can be classified in aquatic chronic 3 category as per the CLP classification criteria.

 

Thus, based on the criteria of readily biodegradable in water, test chemical considers to be nontoxic and not classified as per the CLP classification criteria.