Benzyl benzoate

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:

20/02/2003 - 16/09/2003

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

This study was carried out according to OECD 202 and GLP standards. As such it is considered to be Klimisch 1.

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

yes

Remarks:

Test guideline prefers test groups to be split into 4 replicates, each containing 5 individuals

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

Analytical samples (20 mL) were collected into 40 mL glass VOA vials containing 1 drop of concentrated H3PO4.

Vehicle:

no

Details on test solutions:

17 mg/L stock solutions were prepared, by bringing 0.0171 or 0.0172 g of test substance to 1,000 mL with dilution water. The solutions were mixed on a magnetic stirrer for approximately 5 minutes, sonicated for approximately 15 minutes, and then mixed on a magnetic stirrer until dissolved. A test series of solutions was then prepared by bringing appropriate volumes of stock solution to 250 mL with dilution water.

Test organisms (species):

Daphnia magna

Details on test organisms:

Juvenile Daphnia magna (less than 24 hours old) produced in an in-house culture were used for this test. The original culture was obtained from Aquatic biosystems Inc., Fort Collins, Colorado on the 20th Febuary 2003.
Prior to testing, the daphnid culture was maintained in 100% dilution water under static renewal conditions and the test organisms were not treated for disease.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Post exposure observation period:

Not applicable

Hardness:

160 - 180 mg/L CaCO3

Test temperature:

19.4-20.7oC

pH:

6.9-7.0

Dissolved oxygen:

8.1-8.9 mg/L

Salinity:

Not applicable

Nominal and measured concentrations:

Nominal test concentrations: 1.3, 2.2, 3.7, 6.1, 10 and 17 mg/L
Measured concentrations: 1.09, 1.73, 2.98, 5.11, 8.74 and 14.6 mg/L

Details on test conditions:

See methods below

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

1.73 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

4.26 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 95% CL= 8.93 - >14.6 mg/L

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

3.09 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 95% CL= 2.69 - 3.55 mg/L

Duration:

24 h

Dose descriptor:

LC50

Effect conc.:

11 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mortality

Remarks on result:

other: 95% CL= 8.93 - >14.6 mg/L

Duration:

48 h

Dose descriptor:

LC50

Effect conc.:

7.77 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mortality

Remarks on result:

other: 95% CL = 5.11 - 14.6 mg/L

Details on results:

Exposure of daphnids to benzyl benzoate resulted in an immobility:
24 hour EC50 of 4.26 mg/L (95% CI = 3.74 to 4.80 mg/L)
48 hour EC50 of 3.09 mg/L (95% CI = 2.69 to 3.55 mg/L).

This exposure also resulted in a:
24 hour LC50 of 11.0 mg/L (95% CI = 8.93 to >14.6 mg/L)
48 hour LC50 of 7.77 mg/L (95% CI = 5.11 to 14.6 mg/L).

The slopes of the dose response curves based on effects and mortality were 8.3 and 4.6, respectively. The 48 hour no observed effect concentration (NOEC) was 1.73 mg/L benzyl benzoate.

Reported statistics and error estimates:

Results of the toxicity test were interpreted by standard statistical techniques. The 24 and 48 hour LC50 and EC50 values were calculated using the binomial or probit methods (Stephan et al. 1978). The slopes of the concentration-response curves were calculated using the probit method. The no observed effect concentration (NOEC) is the highest tested concentration of test substance that allowed 90% or greater survival without any sublethal effects.

Table 1: Immobilisation and mortality data

Mean measured concentration (mg/L)	Number alive at 48 hours	Number immobilised 48 hours	Number of dead daphnia 48 hours
Control	20	0	0
1.09	20	0	0
1.73	19	0	0
2.98	19	6	1
5.11	19	19	1
8.74	7	7	13
14.6	0	0	20

Validity criteria fulfilled:

yes

Conclusions:

The 48 hour EC50 for benzyl benzoate was determined to be 3.09 mg/L and the NOEC 1.73 mg/L.

Executive summary:

The acute toxicity of benzyl benzoate to Daphnia magna was tested in an OECD 202 guideline study. Daphnia magna were exposed to benzyl benzoate for 48 hours at nominal concentrations of 0 (control), 1.3, 2.2, 3.7, 6.1, 10, and 17 mg/L. The test was performed under static-renewal conditions in sealed vials at a temperature of 20 ±1oC.The number of surviving organisms, the occurrence of immobility and sub-lethal effects were noted at 0, 24, and 48 hours after test initiation.

The 48 hour EC50 for benzyl benzoate was determined to be 3.09 mg/L and the NOEC 1.73 mg/L.

Description of key information

In an OECD 202 guideline test the EC50 for benzyl benzoate was found to be 3.09 mg/L and the NOEC was determined to be 1.73 mg/L.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

EC50

Effect concentration:

3.09 mg/L

Additional information

The acute toxicity of benzyl benzoate to Daphnia magna was tested in an OECD 202 guideline study. Daphnia magna were exposed to benzyl benzoate for 48 hours at nominal concentrations of 0 (control), 1.3, 2.2, 3.7, 6.1, 10, and 17 mg/L. The test was performed under static-renewal conditions in sealed vials at a temperature of 20 ±1°C.The number of surviving organisms, the occurrence of immobility and sub-lethal effects were noted at 0, 24, and 48 hours after test initiation.

The 48 hour EC50 for benzyl benzoate was determined to be 3.09 mg/L and the NOEC 1.73 mg/L.