3-ethyloxetane-3-methanol

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:

2009

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

Does not meet important criteria of test guideline (e.g. confirmatory analysis of test solutions not reported). Although analysis has not been conducted and test is in accordance with old guideline nominal test concentrations are high and substantially exceed the guideline maximum concentration of 100 mg/L it can be concluded that TMPO is not toxic to zebra fish

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

Report states that sample at 0 and 24 hours were taken for analysis and supplied to the sponsor for analysis. No results have been presented to confirm concentrations were achieved.

Vehicle:

no

Details on test solutions:

Test solutions were prepared on a daily basis, via preparation of a stock solution prepared a 100 g/L. 100 g of Trimethylolpropane oxetane was dissolved per one litre of aerated dilution and serially diluted to prepare the remaining test concentration range of 10000, 5000, 2500, 1200 and 600 mg/L

Test organisms (species):

Danio rerio (previous name: Brachydanio rerio)

Details on test organisms:

The fish were received in May 2008 from the import quarantine and were placed in an internal quarantine for 14 days before commencement of the test.

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Post exposure observation period:

Not applicable

Hardness:

250±25 mg calcium carbonate/L.

Test temperature:

The temperature was 23 ± 1°C

pH:

7.4 to 8.0

Dissolved oxygen:

71 to 101 %ASV

Salinity:

Not applicable

Conductivity:

Not applicable

Nominal and measured concentrations:

Nominal concentrations: Control, 600, 1200, 2500, 5000 and 10000 mg/L

Details on test conditions:

The fish were tested in 5 L glass vessels, ten fish per group. The test was performed in normal laboratory illumination with a light: dark cycle of 16:8 hours. The temperature was 23±1°C in the different test groups during the exposure.

Reference substance (positive control):

yes

Remarks:

disodium heptachromate.

Duration:

24 h

Dose descriptor:

LC50

Effect conc.:

7 500 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

7 500 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

24 h

Dose descriptor:

NOEC

Effect conc.:

5 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

5 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

In all fish at a nominal concentration of 2500 mg/L visible abnormalities were observed. Therefore, it would be expected that the NOEC for the study should be 2500 mg/L. Yet the study director/author has chosen to report the NOEC as 5000 mg/L. It is not clear from the data presented why a NOEC of 2500 mg/L has not been reported.

At the maximum nominal test concentration of 10000 mg/L, 30% mortality occured at 3 hours and 100% mortality at 24 hours.

Results with reference substance (positive control):

The fish batch was qualified for testing purposes with disodium heptachromate. The 24-hour LC50-value fulfilled the acceptance criterion of 200-400 mg/l (SS 028162)

Reported statistics and error estimates:

Statistical methods not described

Sublethal observations / clinical signs:

Visible abnormalities (e.g. darker pigmentation, loss of equilibrium, disturbance in swimming behaviour or increased respiration rate) were observed in all fish at a nominal concentration of 2500 mg/L.

The table below presents the mortality during the 96 hour test:

Nominal concentration (mg/L)	% mortality
	3 hours	24 hours	48 hours	72 hours	96 hours
Control	0	0	0	0	0
600	0	0	0	0	0
1200	0	0	0	0	0
2500	0	0	0	0	0
5000	0	0	0	0	0
10000	30	100	100	100	100

Validity criteria fulfilled:

no

Conclusions:

Analytical results have not been presented or made available, this is a requirement of OECD 203

Executive summary:

A "Fish, Acute Toxicity Test" was performed on the test item Trimethylolpropane oxetane. The test method was based on OECD TG no 203, "Fish, Acute Toxicity Test".

Every 24 -hour exposure period, 100 g Trimethylolpropane oxetane was dissolved per one litre of aerated dilution water as a stock solution, this stock solution was diluted to provide nominal test concentrations of 600, 1200, 2500, 5000 and 1000 mg/L. Portions of the test solution were sampled before test and after 24 hours for analysis in the Sponsor's laboratory.

The fish were incubated under semi-static conditions with exchange of test and control solutions every 24 hours during the 96 hour incubation period.

Visible abnormalities (e.g. darker pigmentation, loss of equilibrium, disturbance in swimming behaviour or increased respiration rate) were observed in all fish at the nominal concentration of 2500 mg/L.

Mortality was observed at 3, 24, 48, 72 and 96 hours of the test, the mortality observations are presented below:

Nominal concentration (mg/L)	% mortality
	3 hours	24 hours	48 hours	72 hours	96 hours
Control	0	0	0	0	0
600	0	0	0	0	0
1200	0	0	0	0	0
2500	0	0	0	0	0
5000	0	0	0	0	0
10000	30	100	100	100	100

The following validity criteria were achieved:

- Constant conditions should be maintained as far as possible throughout the test and, if necessary, semi-static procedures or flow- through procedures should be used.

- The mortality in the controls should not exceed 10% at the end of the test (or one fish if less than ten are used).

- The dissolved oxygen concentration should be above 60% of the air saturation value in the test groups.

No evidence of measured test concentrations have been reported and therefore the TG requirement for evidence identifying that test concentrations were maintained throughout the duration of the test was not fulfilled.

Based on the nominal concentrations it was concluded that the LC50 and No Observable Effect Concentration (NOEC) were found to be 7500 mg/L and 5000 mg/L.

Due to the lack of analytical chemistry the data is insufficient for convincing expert judgment to conclude that test conditions were maintained satisfacatorily. In addition based on species sensitivity relationships the rainbow trout (Oncorhynchus mykiss) is considered to be a more sensitive indicator species than zebrafish, expert opinion would question whether the correct sensitive species of fish has been used for testing purposes. Even though there are deficiencies within the study, nominal test concentration greatley exceeded the maximum guideline test concentration required (100 mg/L), as a result it can be concluded that the test substanc is not toxic to zebrafish and therefore in the interests of animal welware the test is considered acceptable for conclusions to be drawn

Description of key information

The 96-hour LC50 was found to be 7500 mg/l, thereby exceeding the normal highest dose recommended for such studies (1000 mg/L). Therefore, in the chemical safety assessment performed according to Article 14(3) in connection with Annex I section 3 (Environmental Hazard Assessment) no hazard was identified, therefore no PNEC can be derived. 

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

7 500 mg/L

Additional information

A "Fish, Acute Toxicity Test" was performed on the test item 3-ethyloxetane-3-methanol. The test method was based on OECD TG no 203, "Fish, Acute Toxicity Test".

Based on the nominal concentrations it was concluded that the LC50 and No Observable Effect Concentration (NOEC) were found to be 7500 mg/L and 5000 mg/L respectively.