5-ethyl-1,3-dioxane-5-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:

August-September 1993

Reliability:

2 (reliable with restrictions)

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

yes

Remarks:

No analytical chemistry conducted

GLP compliance:

yes

Specific details on test material used for the study:

Batch number 9206

Analytical monitoring:

no

Details on sampling:

No analytical results have been reported, however, page 12 of the report states "that portions of stock and test solutions were sampled and delivered to the sponsor for analysis. The results should be based on the measured concentration if the deviation from the nominal concentration is greater than 20%''.

Vehicle:

no

Remarks:

the substance is highly soluble in the water therefore, no vehicle was needed.

Details on test solutions:

Test solution prepared at a single test concentration of 1000 mg/L. Although it is not specifically stated it is assumed that a direct addition of test substance followed by dilution was used. A control group was also prepared with dilution water only. Both solutions were aerated to oxygen saturation >90%.

Test organisms (species):

Danio rerio (previous name: Brachydanio rerio)

Details on test organisms:

The fish were received on 18 June 1993 from the import quarantine and place in an internal quarantine for 14 days before commencement of the test

Test type:

semi-static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

96 h

Remarks on exposure duration:

10 fishes in each group (in control and 1000mg/l)

Post exposure observation period:

Not applicable

Hardness:

250 ±25 mg

Test temperature:

24 ± 1˚C

pH:

6.9 to 7.9

Dissolved oxygen:

72 to >100%

Salinity:

Not applicable

Nominal and measured concentrations:

Nominal concentrations: Control and 1000 mg/L

Details on test conditions:

The fish were incubated semi-statically in 24 hr intervals during 96 hours.Dilution water as specified in the standard was used. The dilution water was aerated to oxygen saturation exceeding 90%.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 kept at 24±1° C. The total load was 0.6 grams of fish per litre.The definitive test was only performed with one control and one test concentration, 1 000 mg/L.

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

The criteria for the validity of the test according to OECD no 203 were fulfilled:
- constant conditions were maintained as far as possible throughout the test through semi-static procedures
- the mortality in the controls did not exceed 10% at the end of the test- the dissolved oxygen concentration was at least 60% of air saturation value
- the sensitivity of the fish population used in the potassium dichromate control was 366 mg/L which is in accordance with the Swedish Standard SS 02 81 62.

Results with reference substance (positive control):

The sensitivity of the fish population used in the potassium dichromate control was 366 mg/L which is in accordance with the Swedish Standard SS 02 81 62

Reported statistics and error estimates:

Not applicable

Validity criteria fulfilled:

no

Remarks:

1. in the control the mortality did not exceed 10% (or one fish, if fewer than 10 control fish are tested) at the end of the exposure; 2. DO concentration was >60% throughout the experimental period. 3. no analytical chemistry data (not fulfilled)

Conclusions:

Test validity criteria achieved. However, guideline requirement for confirmation of test concentrations was not satisfied.

Executive summary:

The test method was based on OECD TG no 203, "Fish, Acute Toxicity Test".

 

The toxicity of Cyclic TMP Formal (5-ethyl-1,3-dioxane-5-methanol) to zebra fish was assessed by incubation using semi-static, 24 hour renewal regime over the course of 96 hours.

 

Dilution water as specified in the standard was used. The dilution water was aerated to oxygen saturation exceeding 90%. 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 kept at 24±1° C. The total loading rate was 0.6 grams of fish per litre.

 

The definitive test was performed with one control and one test concentration, 1 000 mg/L.

 

The pH in test vessels was maintained at 6.8 to 7.9 and oxygen at >72% ASV.

 

Under the conditions of this test Cyclic TMP Formal was considered to non-toxic to Zebrafish and the 96 -hour LC50 was considered to be >1000 mg/L. Although a biological endpoint was achieved the test was conducted in accordance with an old version of the OECD 203 guideline, samples of test solutions were taken for analysis by the sponsor but these results have not been made available, it is therefore not possible to determine whether concentrations were maintain at 80 - 120% of nominal for the duration of the test and thereby the reported data is not sufficient for expert judgement.

 

To attempt to find convincing data to demonstrate that test concentrations were achieved the Hydrolysis report (W09 - 1383) was reviewed. This report stated that CTF was found to be hydrolytically stable for five days at pH 7 and 9, which encompasses the conditions for this study and therefore it may be possible to assume that test concentrations may have been maintained during the study.

 

In addition the Biodegradation study (08 -290 -3) demonstrated little reduction of DOC in the first 7 days at 20 -25° C which indicates that limited degradation may have occurred during the fish test. Finally the water solubility for CTF stated on the SRC PHYSPROP database is reported to be > 217000 mg/L (217 g/L) and therefore it can be concluded that this fish test was conducted within the limit of water solubility.

 

Although the test is deficient, in the interests of animal welfare, the data is sufficient to conclude that the LC50 is >1000 mg/L which is ten-fold higher than the maximum test concentration required by the OECD TG

Description of key information

The key study derived an LC50 for Zebra fish, Brachydanio rerio >1000 mg/L.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Dose descriptor:

LC50

Remarks:

mg/l

Effect concentration:

1 000 mg/L

Additional information

A single key study is provided. It can be concluded from this study that 5-ethyl-1,3-dioxane-5-methanol was not acutely toxic to zebra fish at a nominal concentration of 1000 mg/L. The LC50 is therefore considered to be >1000 mg/L.