OO-tert-butyl monoperoxymaleate

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:

02 September - 23 October 2017 (Experimental phase)

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:

17 July 1992

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: M-161001
- Expiration date of the lot/batch: 07 October 2017
- Purity test date: 12 September 2017

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: Keep only in the original container. Protect from heat and direct sunlight. Store at max. +30°C
- Stability under test conditions: not stable

Analytical monitoring:

yes

Details on sampling:

- Concentrations (mg/L): 0.0 (Sample code: NC), 10 (Sample code: A)
- Sampling method: The samples were filled into 2 mL microcentrifuge tubes and stored in the freezer (≤ -18 °C). The sampling was conducted according to the following specification:
• After 0 h exposure, NC and A were sampled; 3 samples of 1.5 mL per treatment group.
• After 24 h, 48 h and 72 h exposure:
• Before renewal of the test solutions, NC and A were sampled; 3 samples of 1.5 mL per treatment group.
• After renewal of the test solutions, NC and A were sampled; 3 samples of 1.5 mL per treatment group.
• After 96 h exposure, NC and A were sampled; 3 samples of 1.5 mL per treatment group.

Substance-specific analysis was performed at the test site biochemA GmbH. Of each sampled treatment, one of the samples from 0 h, 24 h, 48 h, 72 h (before and after renewal) and 96 h was sent to the analytical laboratory at the test site biochemA GmbH for chemical analysis.

- Sample storage conditions before analysis: The samples were filled into 2 mL microcentrifuge tubes and stored in the freezer (≤ -18 °C).

Vehicle:

no

Details on test solutions:

The stock solutions were prepared by adding 70.0 – 70.4 mg test item to 7 L test medium and stirring for 1 h using a magnetic stirrer at 22 – 23 °C.

Test organisms (species):

Danio rerio (previous name: Brachydanio rerio)

Details on test organisms:

The test organism Danio rerio originates from the in-house breeding of Hydrotox GmbH. The zebrafish are cultured at 26 ± 2 °C with 14 h light : 10 h dark and aeration with air pumps. They are kept in glass tanks, equipped with external filters, at ≤ 1 fish/L. On workdays, they are fed with commercial fish food (TetraMin flake food, Tetra GmbH, Melle, Germany) and two times per week with freshly hatched Artemia salina larvae. At least every two weeks, ≥ ⅓ of the tank volume is replaced with fresh charcoal filtered tap water. The used test animals had a total length of ca. 2.5 cm and were ca. 9 months old.

FEEDING DURING TEST: No
Seven days before the start of the test, the fish were kept under test conditions in test medium at 23.5 — 25.6 °C. They were fed every working day with commercial fish food (TetraMin) until 24 h before test start, when feeding was stopped.

Test type:

semi-static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

96 h

Remarks on exposure duration:

renewal of test solutions after 24 h, 48 h and 72 h

Test temperature:

The temperature during the exposure was 22.6 – 23.3 °C in the control and 22.7 – 23.6 °C in the test item treatment (required 21 – 25 °C).

pH:

The pH was 7.6 – 7.9 in the control and 7.7 – 7.8 in the test item treatment.

Dissolved oxygen:

The dissolved oxygen concentration was 7.7 – 8.1 mg/L in the control and 7.8 – 8.0 mg/L in the test item treatment (≥ 60 % of the air saturation).

Nominal and measured concentrations:

nominal concentration (mg/L): 10.0

Details on test conditions:

The test vessels were set up in a climatised room with 14 h light : 10 h dark. A semi-static test design was applied. After 24 h, 48 h and 72 h exposure, the test organisms were transferred to a new set of test vessels with new test solutions by means of a net (renewal of test solutions).
Mortality as well as appearance and behaviour of the animals were assessed after 24 h, 48 h, 72 h and 96 h exposure.
The pH, conductivity and O2-concentrations were measured daily. The temperature was measured continuously.

TEST SYSTEM
- Test vessel: Glass tanks
- Type (delete if not applicable): open
- Material, size, headspace, fill volume: 8 L
- Type of flow-through (e.g. peristaltic or proportional diluter): No: Semi-static system
- Renewal rate of test solution (frequency/flow rate): yes, after 24 h
- No. of organisms per vessel: 7
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1


TEST MEDIUM / WATER PARAMETERS : The test was performed with ISO 7346 medium according to EN ISO 7346 (1997): refer to information given in "Any other information on materials and methods" below.

Key result

Duration:

96 h

Dose descriptor:

LOEC

Effect conc.:

> 5.34 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Key result

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

>= 5.34 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

As no fish died until the end of the exposure, the mortality in the control as well as in the test item treatment was 0 %.
No obvious effect on appearance and behaviour of the fish in the test item treatment was observable. All test organisms in the control as well as in the test item treatment appeared healthy and lively throughout the exposure.

As the measured test item concentrations are not within ± 20 % of the nominal concentration, all results are given in relation to the analytically measured test item concentrations (geometric mean concentrations).
Lowest/No Observed Effect Concentration Measured test item concentration [mg/L]
LOEC > 5.34
NOEC ≥ 5.34

Reported statistics and error estimates:

• No mortality of test organisms occurred in the control until the end of the test and was therefore ≤ 1 fish.
• Dissolved oxygen concentration in the control and the test item treatment throughout the test was ≥ 7.7 mg/L and therefore ≥ 60 % of the air saturation

Validity criteria fulfilled:

yes

Conclusions:

No mortality or sublethal effcets were noted in an acute toxicity test with D. rerio conducted according to the Threshold Approach for Acute Fish Toxicity. Thus, fish is not the most sensitive group of test organisms after short-term exposure and no further testing (i.e. full EC50 Fish Acute Toxicity Test) is required.

Executive summary:

In a 96-h acute toxicity study, zebra fish (Danio rerio) were exposed to OO-tert-butyl monoperoxymaleate at nominal concentrations of 0.0 (control) and 10 mg/L (limit test) under semi-static conditions. The NOEC value, based on mortality and sublethal effects, was ≥ 5.34 mg/L (measured concentration). Sublethal effects were not observed.

The absence of any mortality indicates that, according to the Threshold Approach for Acute Fish Toxicity, fish is not the most sensitive group of test organisms after short-term exposure and no further testing (i.e. full EC50 Fish Acute Toxicity Test) is required.

Based on the results of this study, the test item would be not classified as toxic to zebra fish in accordance with the CLP classification system.

This toxicity study is classified as acceptable and satisfies the guideline requirement for the zebra fish acute toxicity study.

 

Results Synopsis

 

Test organism size/age: Danio rerio (ca. 2.5 cm, app. 9-month-old)

Test Type: semi-static; threshold approach

 

NOEC:  ≥ 5.34 mg/L (measured concentration)                    

LOEC: > 5.34 mg/L (measured concentration)

Endpoint(s) Effected: mortality and abnormal effects

Description of key information

In a 96-h acute toxicity study, zebra fish (Danio rerio) were exposed to OO-tert-butyl monoperoxymaleate at nominal concentrations of 0.0 (control) and 10 mg/L under semi-static conditions (limit test). The NOEC value, based on mortality and sublethal effects, was ≥ 5.34 mg/L (measured concentration).  The LOEC was > 5.34 mg/L. Sublethal effects were not observed.

The absence of any mortality indicates that, according to the Threshold Approach for Acute Fish Toxicity, fish is not the most sensitive group of test organisms after short-term exposure to OO-tert-butyl monoperoxymaleate.