tert-butyl peroxyneodecanoate

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:

2012-02-13 to 2012-02-17

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Version / remarks:

adopted 1992

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.1 (Acute Toxicity for Fish)

Version / remarks:

adopted 2008

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 850.1075 (Freshwater and Saltwater Fish Acute Toxicity Test)

Version / remarks:

adopted 1996

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 0.19, 0.34, 0.62, 1.11 mg/L
- Sampling method: Three replicates samples were taken at the start and two parallel samples were taken at the end of the renewal periods from the test formulation and from the control samples. One sample was taken from the solvent control.

Vehicle:

yes

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: The test item is a hydrolytically unstable material. In order to minimise hydrolysis before introduction of the fish (treatment) the test solutions were prepared using water-miscible solvent (acetone) as follows: For preparation of each test concentration, individual stock solutions were prepared by dissolving an appropriate amount of test item in acetone. At first step, a work solution (concentration: 20.0 g/L) was prepared by diluting an amount of 0.50 g test item in 25 mL acetone and then the stock solutions were prepared by appropriate diluting of this work solution in acetone. The test solutions of the chosen test concentrations were prepared by appropriate diluting of these stock solutions in the dilution water (ISO medium), each immediately before analytical measurement and treatment.
- Chemical name of vehicle: acetone

Test organisms (species):

Danio rerio (previous name: Brachydanio rerio)

Details on test organisms:

TEST ORGANISM
- Common name: Zebrafish
- Source: The test fish were bred and held in Fish Laboratory of TOXI-COOP Zrt. (8237 Tihany, Klebelsberg K. u. 3.).
- Age at study initiation: Juveniles
- Length at study initiation: 2 ± 1 cm
- Method of breeding: similar conditions (water temperature, pH, oxygen concentration etc.) and in the same type of water as that used in the experiment
- Feeding during test: no

ACCLIMATION
- Acclimation period: no acclimatization period

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Hardness:

approx. 249 mg/L CaCO3

Test temperature:

21.2 – 22.9 °C

pH:

7.45 – 7.97

Dissolved oxygen:

76.8 – 98.1 %

Nominal and measured concentrations:

0.19, 0.34, 0.62, 1.11 and 2.00 mg/L (nominal concentration)
0.07, 0.12, 0.24, 0.46 and 0.73 mg/L (measured concentration)

Details on test conditions:

TEST SYSTEM
- Test vessel: Glass aquariums with 1.5 litre test liquid, covered with glass lids
- Renewal rate of test solution: 24 hours
- No. of organisms per vessel: 7 animals
- No. of vessels per concentration: one replicate
- No. of vessels per control: one replicate
- No. of vessels per vehicle control: one replicate
- Additional test solution control group: An additional test item solution control group (1.1 mg/L) without addition of fish was included in the experiment and analysed at the same occasions as the test concentrations in order to check the possibility of the adsorption of test item on test animals.
- Biomass loading rate: 1.0 mg/L

TEST MEDIUM / WATER PARAMETERS
- in accordance to the guideline

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16 h light: 8 h dark

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 1.8

Reference substance (positive control):

no

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

0.33 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: 95 % conf. limits was not applicable since LC50 was calculated as the geometric mean of the highest test concentration causing no mortality and the lowest concentration causing 100 % mortality

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

0.24 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

LOEC

Effect conc.:

0.46 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

Concentration of the additional test solution control (1.11 mg/L nominal; without addition of fish) was determined at the same occasions as that performed at this concentration including fish. Considerable difference between the two groups was not observed. Therefore, it could be concluded that no adsorption of the test item on fish occurred.

Validity criteria fulfilled:

yes

Conclusions:

The 96 h LC50 value was determined as 0.33 mg/L, and the 96 h NOEC was determined as 0.24 mg/L.

Executive summary:

The purpose of this study was to evaluate the influence of the test item TBPND on zebrafish (Brachidanio rerio). Young fish were exposed in an acute toxicity test to aqueous test media containing the test item for 96 hours at a range of concentration under semi-static conditions. The frequency of the renewal periods was 24 hours. Based on the results of pre-experiments the following five test concentrations in a geometric series (with a separation factor of 1.8) were tested: 0.19, 0.34, 0.62, 1.11 and 2.00 mg/L (nominal) prepared in solvent (acetone). The measured concentrations deviated more than 20 % from the nominal during the experiment therefore the geometric mean of the measured concentrations were calculated in order to determine exposure concentrations. The calculated geometric mean concentrations were the following: 0.07, 0.12, 0.24, 0.46 and 0.73 mg/L. The 96 h LC50 value was determined as 0.33 mg/L, and the 96 h NOEC was determined as 0.24 mg/L.

Description of key information

The acute toxicity to fish was assessed according to OECD guideline 203, EU-method C.1 and EPA OPPTS 850.1075. In this 96-hour semi-static acute toxicity test with zebrafish, the LC50 value was 0.33 mg/L (measured concentration). The no-observed-effect concentration (NOEC) was 0.24 mg/L (measured concentration).

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

0.33 mg/L

Additional information

The purpose of this study was to evaluate the influence of the test item TBPND on zebrafish (Brachidanio rerio). Young fish were exposed in an acute toxicity test to aqueous test media containing the test item for 96 hours at a range of concentration under semi-static conditions. The frequency of the renewal periods was 24 hours. Based on the results of pre-experiments the following five test concentrations in a geometric series (with a separation factor of 1.8) were tested: 0.19, 0.34, 0.62, 1.11 and 2.00 mg/L (nominal) prepared in solvent (acetone). The measured concentrations deviated more than 20 % from the nominal during the experiment therefore the geometric mean of the measured concentrations were calculated in order to determine exposure concentrations. The calculated geometric mean concentrations were the following: 0.07, 0.12, 0.24, 0.46 and 0.73 mg/L. The 96 h LC50 value was determined as 0.33 mg/L, and the 96 h NOEC was determined as 0.24 mg/L.