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

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From 13/06/2008 to 01/08/2008

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

This semi-static study was performed according to OECD Guideline 203 with GLP statement. In presence of fish, there is a marked decrease in the test item concentrations (from 1.85-2.48 mg/L for new solutions to lower than the detection limit of the analytical method: 0.33 mg/L for old solutions) during each 24 hours period of exposure (due to bioaccumulation, adsorption and/or volatilization and hydrolysis). Nevertheless, this study allows to conclude that there is no acute toxicity up to the highest available concentration in solution (no effect up to 2.11 mg/L).

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

yes

Remarks:

, minor deviation: five fish were used at each test concentrations and in the control, instead of at least 7.

Principles of method if other than guideline:

Not applicable

GLP compliance:

yes (incl. QA statement)

Remarks:

2008-05-06

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
- water solubility = 2.597 to 4.0874 mg/L at 25°C
- relative density at 20°C = 920 Kg/m3

Analytical monitoring:

yes

Details on sampling:

No data

Vehicle:

no

Details on test solutions:

The preliminary test was carried out in semi-static mode, wih renewal of solutions. Three were prepared by mixing 200, 100 and 50 mg of the test item per litre of dilution water in order to obtain 5 litres of each solution that was kept under stirring during 67h for the first session, then 22h for the 3 following ones. The day of the test, solutions were filtered on Millipore HVLP 14250 membrane, that was first rinsed with dilution water and 300 mL of the corresponding solution.
Based on the results of preliminary test, the definitive test was carried out in semi-static mode at the concentration 100 mg/L (limit test). Solutions were prepared the same manner.

Test organisms (species):

Danio rerio (previous name: Brachydanio rerio)

Details on test organisms:

TEST ORGANISM
- Common name: Danio rerio (Teleostei, Cyprinidae)
- Strain: Batch n° 08/Br/01/1
- Source: Aquatrade France (44150 ANCENIS)
- Age at study initiation (mean and range, SD): the fish selected for the test were all from the same batch and were of the same age, date of birth stated by the supplier is 06/02/2008.
- Length at study initiation (length definition, mean, range and SD): 3.3 +/- 0.22 cm
- Weight at study initiation (mean and range, SD): average = 0.53 g/fish
- Feeding during test: TetraPro (Tetra GmbH, D-49304 Melle, Germany)

Test type:

semi-static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

96 h

Remarks on exposure duration:

none

Post exposure observation period:

None

Hardness:

No data

Test temperature:

between 22.4 +/- 0.5°C

pH:

between 7.75 and 8.13

Dissolved oxygen:

between 89 and 102% air saturation

Salinity:

Not applicable

Nominal and measured concentrations:

See table 2 in "Any other information on results incl. tables".

Details on test conditions:

The study was carried out in a thermostatically constrolled room. The temperature, which was measured on a continuous basis in a test flask, was between 22.4 +/- 0.5°C. The room was equipped with a programmed lighting system which produced a controlled lighting sequence: intensity between 400 and 800 Lux at the surface of the aquariums; photoperiod of 12 hours of darkness per 24h.
The study was performed using aquariums with a nominal capacity of 5L, covered with Altuglas cover plates drilled with holes to allow the test solutions to be aerated. Volume of test medium per aquarium was 2.5L. As 5 fish were added, this corresponding to a fish loading of 1.06 g/L.

Reference substance (positive control):

no

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Key result

Duration:

96 h

Dose descriptor:

EC50

Effect conc.:

> 2.11 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: geometric mean of initial new solutions

Details on results:

The appearance of the test solutions was visually checked at the beginning and at the end of the test. Solutions were found to be clear, colourless over the period of the test. No precipitation was observed at the end of the test.
See tables in "Any other information on results incl. tables".

Results with reference substance (positive control):

Not applicable

Reported statistics and error estimates:

None

Sublethal observations / clinical signs:

Table 6.1.1/1: Nominal and measured concentrations of the test item at the beginning and at the end of the stability test.

Conditions	Time of dissolution (hours)	Nominal concentration (mg/L)	Theor. Analyte (mg/L)	T0 (mg/L)	T24h (mg/L)
Without fish	68	100	100	1.93	1.29
With fish		100			<DL
Without fish	24	100	100	2.22	1.22
With fish		100			<QL

<DL: concentration lower than the detection limit of the analytical method (0.33 mg/L)

<QL: concentration lower than the quantification limit of the analytical method (1.09 mg/L)

These results in table 6.1.1/1 show that 24 or 68 hours of dissolution of the test item did not change the T0 concentration. However, the final concentration appears dependent of the presence of fish.

Table 6.1.1/2: Nominal and measured concentrations of the test item at the beginning and at the end of each 24h period (definitive test).

Nominal concentration (mg/L)	Theor. Analyte (mg/L)	D0 T0h (mg/L)	D1 T24h (mg/L)	D1 T0h (mg/L)	D1 T24h (mg/L)	D2 T0h (mg/L)	D2 T24h (mg/L)	D3 T0h (mg/L)	D3 T24h (mg/L)
0	0	<DL	<DL	<DL	<DL	<DL	<DL	<DL	<DL
0	0	<DL	<DL	<DL	<DL	<DL	<DL	<DL	<DL
100	100	2.04	<DL	2.25	<DL	1.96	<QL	ND	<QL
100	100	1.88	<DL	2.48	<DL	1.85	<QL	2.41	<DL

<DL: concentration lower than the detection limit of the analytical method (0.33 mg/L)

<QL: concentration lower than the quantification limit of the analytical method (1.09 mg/L)

As already observed in the stability test, in presence of fish, there is a marked decrease in the test item concentrations during each 24 hours period of exposure (table 6.1.1/2).

Table 6.1.1/3: Definitive test - percentage of dead fish:

Loading rate (mg/L)	Mortality (%)
	24h	48h	72h	96h
100	0	0	0	0
0	0	0	0	0

No mortality of fish was observed up to a loading rate of 100 mg/L (table 6.1.1/3).

Validity criteria fulfilled:

no

Remarks:

The concentration of the substance being tested hasn't been satisfactorily maintained (at least 80 per cent of the nominal concentration) throughout the test and the results were not based on measured concentrations.

Conclusions:

No toxicity effect was detected, due to the test item or its degradation products, up to a loading rate of 100 mg/L. The 96h-LC50 was greater than 100 mg/L, corresponding to > 2.11 mg/L based on geometric mean initial measured concentration in new solutions.

Executive summary:

The acute toxicity of the test item to Danio rerio for a duration of 96 hours was assessed according to the OECD guideline 203 and GLP statement.

Fish were exposed under semi-static conditions to 100 mg/L of the test item dissolved in dilution water (limit test).

No mortality of fish was observed up to a loading rate of 100 mg/L. The 96h-LC50 was greater than the loading rate of 100 mg/L, corresponding to greater than 2.11 mg/L based on geometric mean initial measured concentration in new solutions.

Description of key information

GLP study performed according to OECD 203 guideline: 96h-LC50 >100 mg/L (nominal concentration).

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

100 mg/L

Additional information

The acute toxicity of the test item to Danio rerio for a duration of 96 hours was assessed according to the OECD guideline 203 and GLP statement. Fish were exposed under semi-static conditions to 100 mg/L of the test item dissolved in dilution water (limit test). No mortality of fish was observed up to a loading rate of 100 mg/L. The 96h-LC50 was greater than the loading rate of 100 mg/L, corresponding to greater than 2.11 mg/L based on geometric mean initial measured concentration in new solutions.