OO-tert-butyl O-(2-ethylhexyl) peroxycarbonate

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 30 October 2001 to 01 November 2001

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

This study was performed according to OECD Guideline 202 and EU Method C2 with GLP statement. All validity criteria were fulfilled. The study has flaws because no dilutions should be done from a WAF but nevertheless, this study allows to conclude that there is no acute toxicity up to the highest available concentration in solution (0.48 mg/L) being due to the susbtance itself or degradation products.

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Deviations:

no

Principles of method if other than guideline:

Not applcable

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

A sample of 4 mL was taken from the LS solution container at the beginning of the test and stored at -20°C until analysis. Samples totaling 4 mL were also taken at T24 and T48 hours from the LS test vesels containing daphnids and stored at -20°C until analysis.

Vehicle:

no

Details on test solutions:

The stock solution, for the limit and range finding tests, was prepared by dispersing the test item directly in M4 reconstituted water.
A loading rate of 100 mg/L was used to prepare the stock solution. As test item droplets were still in suspension after agitation, the stock solution was filtered through a filter of porosity 0.45 µm to remove the suspended fraction. The filtered solution, corresponding to the limit of solubility of the test item under experimental conditions (LS), was then used to prepare the test solutions.
Test solutions were prepared by further dilution of the LS solution with M4 reconstituted water to provide a geometric series of concentrations: 0 mg/L, LS/1000, LS/100, LS/10 and LS.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna STRAUS-clone 5
- Source: Centre Technique du Bois et de l'Ameublement, 75012 PARIS (France)
- Age at study initiation (mean and range, SD): between 6 and 24 hours oild
- Feeding during test: Animals were not fed during the test

ACCLIMATION
Animals are held in water of the same quality as the test water from birth until use in the test. Animals were randomly placed first into on beaker containing water of the same quality and conditions as the culture water and then 6 hours later, the remaining daphnids were randomly assigned to the test item solutions using a pipette.
Culture animals are fed with a diet of between 0.1 and 0.2 mg of carbon per Daphnia per day, in the form of the algal strain Scenedesmus subspicatus which is cultured at CIT.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Remarks on exposure duration:

none

Post exposure observation period:

None

Hardness:

272 mg/L as CaCO3

Test temperature:

Between 19.4 and 20.4°C

pH:

between 7.42 and 7.62

Dissolved oxygen:

between 8.6 and 9.2 mg/L (> 60%)

Salinity:

Not applicable

Nominal and measured concentrations:

Nominal: 0 mg/L, LS/1000, LS/100, LS/10 and LS.
Measured: See table 6.1.3/1 in "Any other information on results incl. tables"

Details on test conditions:

TEST SYSTEM
- Test vessel: no data
- Aeration: no during the test (dilution water was aerated prior to the addition of the test item)
- Type of flow-through (e.g. peristaltic or proportional diluter): not applicable
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4
- Biomass loading rate: 1 animal/10 mL of solution

TEST MEDIUM / WATER PARAMETERS
Reconstituted M4

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16h light / 8h dark cycle
- Light intensity: no data

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Observations were carried out at 0, 24 and 48 hours in order to determine the number of immobilized daphnids in each test solution.

TEST CONCENTRATIONS
Test solutions were prepared by further dilution of the LS solution with M4 reconstituted water to provide a geometric series of concentrations: 0 mg/L, LS/1000, LS/100, LS/10 and LS.

Reference substance (positive control):

no

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: initial loading rate

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 0.484 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

No immobilization was observed at 0 mg/L, LS/1000, LS/100, LS/10 and LS throughout the test.

Results with reference substance (positive control):

Not applicable

Reported statistics and error estimates:

None

As the test item was not found to be toxic at LS, chemical analysis was undertaken to measure the concentration of the test item in this solution.

The initial concentration of the test item was 0.960 mg/L in the LS solution. The test item was not stable under our experimental conditions since its concentration fell below 80% of the initial value during the test (0.381 mg/L after 48 hours, corresponding approximately to 40% of the initial concentration). The concentration of the test item in the LS solution was considered as the geometric mean of measured concentrations throughout the test (0.484 mg/L).

Table 6.1.3/1: Concentration of the test item in the limit test solution (mg/L)

Nominal	Measured*			Geometric mean
	0h	24h	48h	0-48h
LS	0.960 mg/L	0.310 mg/L	0.381 mg/L	0.484 mg/L

* concentration expressed as test item calculated from the measured concentration of peroxide and the proportion of this component in the test item.

Validity criteria fulfilled:

yes

Conclusions:

No immobilization was observed at 0 mg/L, LS/1000, LS/100, LS/10 and LS throughout the test. The 48h-EC50 of the test item in a static test system is > 100 mg/L expressed as initial loading rate, corresponding to 0.484 mg/L expressed as actual concentration (geometric mean of measured concentrations during the test in the saturated solution obtained from this loading rate of 100 mg/L) for Daphnia magna.

Executive summary:

The acute toxicity of the test item was evaluated in the Cladoceran, Daphnia magna STRAUS (clone 5) using a 48h static test according to OECD Guideline 202 and EU Method C2 with GLP statement.

The test item was dispersed in reconstituted water (M4) prepared from deionized water. The study included a limit test and a range finding test. A loading rate of 100 mg/L was used to prepare the stock solution. As test item droplets were still in suspension after agitation, the stock solution was filtered through a filter of porosity 0.45 µm to remove the suspended fraction. The filtered solution, corresponding to the limit of solubility of the test item under our experimental conditions (LS), was then used to prepare the test solutions. For the limit test, 20 daphnids (in 4 replicates of 5) were exposed to a nominal concentration of LS for 48 hours while a second group of 20 daphnids (in 4 replicates of 5) was exposed to the test dilution water (M4) only (control solution).

For the range finding test, 3 groups of 20 daphnids (in 4 replicates of 5) were subjected to dilutions of the limit test solution at LS/1000, LS/100 and LS/10 for a period of 48 hours.

Environmental parameters were as follows: pH was 7.42 to 7.62; temperature was 19.4°C to 20.4°C; dissolved oxygen concentration was 8.6 to 9.2 mg/L (> 60% of the air saturation value) and water hardness was 272 mg/L as CaCO3.

No immobilization was observed at 0 mg/L, LS/1000, LS/100, LS/10 and LS throughout the test. As the test item was not found to be toxic at LS, chemical analysis was undertaken to measure the concentration of the test item in this solution. The initial concentration of the test item was 0.960 mg/L in the LS solution. The test item was not stable under our experimental conditions since its concentration fell below 80% of the initial value during the test (0.381 mg/L after 48 hours, corresponding approximately to 40% of the initial concentration). The concentration of the test item in the LS solution was considered as the geometric mean of measured concentrations throughout the test (0.484 mg/L).

Hence, the highest concentration resulting in no immobilization at 48h was >= 100 mg/L expressed as initial loading rate, corresponding to 0.484 mg/L expressed as actual concentration (i.e. geometric mean of measured concentrations in the LS solution throughout the test).

Under experimental conditions, the 48h-EC50 of the test item in a static test system is > 100 mg/L expressed as initial loading rate, corresponding to 0.484 mg/L expressed as actual concentration for Daphnia magna.

Description of key information

GLP study performed according to OECD 202 guideline: 48h-EC50 >100 mg/L (nominal concentration)

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

100 mg/L

Additional information

The acute toxicity of the test item was evaluated in the Cladoceran, Daphnia magna STRAUS (clone 5) using a 48h static test according to OECD Guideline 202 and EU Method C2 with GLP statement.

No immobilization was observed throughout the test. As the test item was not found to be toxic at the highest tested concentration, chemical analysis was undertaken to measure the concentration of the test item in this solution.

The initial concentration of the test item was 0.960 mg/L in the highest tested concentration solution. The test item was not stable under our experimental conditions since its concentration fell below 80% of the initial value during the test (0.381 mg/L after 48 hours, corresponding approximately to 40% of the initial concentration). The concentration of the test item was thus considered as the geometric mean of measured concentrations (0.484 mg/L).

As a consequence; under experimental conditions, the 48h-EC50 of the test item in a static test system is > 100 mg/L expressed as initial loading rate, corresponding to 0.484 mg/L expressed as actual concentration for Daphnia magna.