Benzyl propionate

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:

from 2000-08-22 to 2001-05-23

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

1984

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

- Concentrations: each concentration (two parallel measurements)

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: The test substance was weighed into glass vessels with the respective amount of water used for the preparation of the aqueous extracts. The test substance was introduced into the dilution water whilst shaking on a shaking machine (~ 130 rpm) for 24 h at room temperature. Thereafter, the suspensions were filtered through filter paper which was previously rinsed thoroughly with ultrapure water (Seral, „Purelab Plus"). The filtered extracts were used directly for the test without any further dilution steps.
- Controls: Controls were prepared as the same way mentioned above without any test substance.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: water flea
- Strain: Daphnia magna STRAUS
- Age at study initiation: not older than 24h
- Method of breeding: The daphnia were cultivated in drinking water and fed with cells from the unicellular green alga Scenedesmus subspicatus.
- Feeding during test: none

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Post exposure observation period:

none

Test temperature:

20.5 - 21.0°C at t(0 h)
20.9 - 21.1°C at t(48 h)

pH:

7.04 - 7.55 at t(0 h)
7.26 - 7.77 at t(48 h)

Dissolved oxygen:

8.35 - 8.46 mg O2/L at t(0 h)
6.41 - 8.15 mg O2/L at t(48 h)

Salinity:

not applicable

Nominal and measured concentrations:

nominal concentrations: 1, 2, 4, 8 and 16 mg/L
measured concentrations: 1.8, 2.6, 3.8, 6.9 and 12.7 mg/L at t(0 h) and 1.5, 2.4, 3.6, 7.2 and 13.5 mg/L at t(48h) (calculated from the measured TOC-results)

Details on test conditions:

TEST SYSTEM
- Test vessel: 100 mL-Carboys made of glass
- Type: closed (with glass-stoppers)
- Material, size: glass, 100 mL
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4

TEST MEDIUM / WATER PARAMETERS
- according to OECD guideline (ISO test water)
- Culture medium different from test medium: Yes (drinking water was used as culture medium)
- Intervals of water quality measurement: The pH value was measured at the beginning of the test and after 48 h in the control group.

OTHER TEST CONDITIONS
- Adjustment of pH: none
- Photoperiod: 16 h of light and 8 h of darkness

EFFECT PARAMETERS MEASURED:
- The numbers of immobilised daphnia at each concentration of the test substance was recorded after 24 h and 48 h.
- pH, oxygen content and temperature in the test solutions were checked at the beginning and the end of the test (after 48 h).

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 2
- Range finding study
- Test concentrations: 1.0, 10 and 100 mg/L
- Results used to determine the conditions for the definitive study: No immobilisation was observed at a concentration of 1 mg/L of the test substance. 80% and 100% immobilisation were observed at a concentration of 10 mg/L and 100 mg/L, respectively.

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

5.4 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: SD: 14%, 95% CL: 58%

Duration:

48 h

Dose descriptor:

EC0

Effect conc.:

2.2 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: SD: 21%, 95% CL: 91%

Duration:

48 h

Dose descriptor:

EC100

Effect conc.:

13 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: SD: 20%, 95% CL: 86%

Results with reference substance (positive control):

EC50 was 0.9 mg/L (tested once a month)

Additionally, from the measured TOC-values and the known carbon content (72.8%) including the % purity of the test substance (99.6%) and the chemical formula of the test substance, the following concentrations and % recoveries an basis of the nominal concentrations were calculated:

Table 1: Measured concentrations

Nominal Concentraion [mg/L]	Mean calculated Amount of Test Substance [mg/L] at t(0)	Mean calculated Amount of Test Substance [mg/L] at t(48h)	% Recovery at t(0)	% Recovery at t(48h)
0	0	0	0	0
1	1.8	1.5	176.2	154.0
2	2.6	2.4	131.4	119.3
4	3.8	3.6	95.1	90.3
8	6.9	7.2	86.0	90.1
16	12.7	13.5	79.5	84.6

Table 2: Main test - Immbility rates

Concentration of the test substance [mg/L]	Ratio immobilised Daphnia [%]
	24h	48h
Control (0)	0 [0/20]^1)	0 [0/20]^1)
1	0 [0/20]^1)	0 [0/20]^1)
2	0 [0/20]^1)	0 [0/20]^1)
4	0 [0/20]^1)	10 [2/20]^1)
8	20 [4/20]^1)	100 [20/20]^1)
16	65 [13/20]^1)	100 [20/20]^1)

¹⁾Numbers in brackets give the absolute numbers of immobilised animals at each concentration.

Validity criteria fulfilled:

yes

Conclusions:

In a 48-h static toxicity test with Daphnia magna the EC50 value based on mobility of the test substance was found to be 5.4 mg/L.

Executive summary:

In the acute immobilisation test with Daphnia magna (STRAUS), the effects of the test item were determined according to OECD 202 (1984). The study was conducted in a closed system under static conditions using the following test item concentrations: 1, 2, 4, 8 and 16 mg/L (nominal). After 24 and 48 hours, the daphnids were observed for signs of immobility. As a result, the EC50 value of the test substance was found to be 5.4 mg/L after 48 h.

Description of key information

In a 48-h static toxicity test with Daphnia magna the EC50 value based on mobility of the test substance was found to be 5.4 mg/L.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

5.4 mg/L

Additional information

In the acute immobilisation test with Daphnia magna (STRAUS), the effects of the test item were determined according to OECD 202 (1984). The study was conducted in a closed system under static conditions using the following test item concentrations: 1, 2, 4, 8 and 16 mg/L (nominal). After 24 and 48 hours, the daphnids were observed for signs of immobility. As a result, the EC50 value of the test substance was found to be 5.4 mg/L after 48 h.