3,3,5,7,7-pentamethyl-1,2,4-trioxepane

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

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

yes

Remarks:

see Principles of method if other than guideline, The study integrity was not adversely affected by the deviations.

Principles of method if other than guideline:

There were deviations from the test protocol.

1. During the first limit test samples were taken from two different points in the test solution rather than from the middle of the test solutions. Evaluation: this was triggered by the observation variation in measured conc. during the range finding test and was meant to provide relevant information concerning homogeneity of the test solution.
2. During the final limit test, reserve samples were taken even duplicate samples were taken for analysis. Evaluation: this was triggered by the analytical results of the former studies and was aimed at providing relevant information if needed.
3. During the final limit test, recording of the effects was done after 6 ¼ hours instead of 4 hours. Evaluation: Since no effects were observed, this did not have an impact on the test results.

The study integrity was not adversely affected by the deviations.

GLP compliance:

yes

Specific details on test material used for the study:

Clear colourless liquid, purity 96.5%.

Analytical monitoring:

yes

Vehicle:

no

Details on test solutions:

The stock solution was prepared at 100 mg/l. The test substance was dissolved by magnetic stirring. Lower concentrations were prepared by dilution of the stock solution.

Test organisms (species):

Cyprinus carpio

Details on test organisms:

Carp (Cyprinus carpio, Cyprinidae), Zodiac, proefacc, “De Haar Vissen”, Wageningen University and Research Centre, the Netherlands

Mean length:
Range finding test: 3.0 ± 0.2 cm
First limit test: 2.9 ± 0.2 cm
Second limit test: 2.5 ± 0.1 cm

Mean weight:
Range finding test: 0.77 ± 0.14 g
First limit test: 0.73 ± 0.15 g
Second limit test: 0.39 ± 0.13 g

Ten fish of the batch used for the test were weighed and measured prior to the start of the test

Test type:

static

Water media type:

other: In ISO medium, formulated using Milli-Ro water

Limit test:

yes

Total exposure duration:

96 h

Hardness:

250 mg CaCO3 per litre

Test temperature:

20.4 - 21.2 oC

pH:

7.6-8.1

Dissolved oxygen:

6.7-9.3

Nominal and measured concentrations:

Nominal concentrations:
Range finding test: Concentrations of 0.1- 100 mg/l increasing with a factor 10.
First limit test: Blank control and 100 mg/l
Final limit test: Blank control, 100 mg/l and test solution without fish.

Measured concentrations:
Range finding test: the measured conc in the 100 mg/l conc. at t=0 94 mg/l, t=24 60mg/l and t=96 83 mg/l. Reserve samples at t=0 75 mg/l, t=24 79 mg/l and t=96 65 mg/l. After measuring the reserve samples it was assumed that the variability of the analytical results were related to different days of analysis rather than to instability of the test substance.
The first limit test: t=0 71-74 mg/l t=96 decreased to 31 mg/l. Therefore this test did not meet acceptability criteria and a second limit test was performed.

Final limit test:
The test substance was stable

Arithmetic mean was used.

Details on test conditions:

Range finding test: 10 liter vessels, all glass containing 7 liters of test solution.
First limit test: 20 liter vessels, all glass containing 15 liters of test solution.
Final limit test: 10 liter vessels, all glass containing 9 liters of test solution.

Range finding test:
3 fish per conc.
First and final test:
7 fish per conc. and control

Reference substance (positive control):

yes

Remarks:

pentachlorophenol

Key result

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

> 100 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

other: no clinical effects, no mortality

Remarks on result:

other: also 24, 48 and 72 h

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 100 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

other: No clinical effects observed, no mortality

Remarks on result:

other: also 24, 48 and 72 h

Details on results:

No clinical effects were observed, no mortality

Results with reference substance (positive control):

Zero mortality at 0.1 mg/l (nominal); zero through 96 h
100 % mortality at 0.22 mg/l (nominal); zero at 2.25 h, 100 % from 24 h
100 % mortality at 0.46 mg/l (nominal); zero at 2.25 h, 100 % from 24 h

Validity criteria fulfilled:

yes

Conclusions:

Under the conditions of the present test Pentamethyl-trioxepane induced no visible effects in carp at 100 mg/l. The 96h-LC50. was > 100 mg/l based on analytically confirmed nominal concentrations. Based on LC50>100 mg/l, pentamethyl-trioxepane is not classified.

Executive summary:

The 96h-LC₅₀. was > 100 mg/l based on analytically confirmed nominal concentrations.

Description of key information

Under the conditions of the present test Pentamethyl-trioxepane induced no visible effects in carp at 100 mg/l. The 96h-LC50. was > 100 mg/l based on analytically confirmed nominal concentrations. Based on LC50>100 mg/l, pentamethyl-trioxepane is not classified.