Methyl 4-[2-[4-(5-methyl-2-benzoxazolyl)phenyl]vinyl]benzoate

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:

disregarded due to major methodological deficiencies

Study period:

August from 07th to 25th, 1995

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

unsuitable test system

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Qualifier:

according to guideline

Guideline:

EU Method C.1 (Acute Toxicity for Fish)

GLP compliance:

yes

Remarks:

but not inspected

Analytical monitoring:

no

Details on test solutions:

The test substance was mixed with dilution water, homogenized with the Ultra-Turrax and introduced with stirring with a glass rod in the test tanks. The contents of the basin were then stirred for about 30 minutes with a KPG stirrer and glass rod.

Test organisms (species):

Danio rerio (previous name: Brachydanio rerio)

Details on test organisms:

TEST ORGANISM
- Common name: zebrafish
- Source: Eigenzucht HOECHST AG, Kastengrund
- Length at study initiation: average 3.4 cm (3.1 - 3.5 cm; SD: ± 0.12).

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Test temperature:

21.3 - 21.9 °C

pH:

7.7 - 8.2

Dissolved oxygen:

5.9 - 9.1 mg/l

Nominal and measured concentrations:

0, 100, 220, 500 and 1000 mg/l, nominal

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

220 - 500 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

The LC50 resulted to be above the solubility limit of the test substance in water. Because of the strong turbidity of the test water through the test substance, the symptom observation was limited. In all the tested concentrations an impairment of the swimming behavior, the respiration as well as a changed behavior was observed.

TEST SOLUTION APPEARANCE
The test batches showed a strong turbidity with substance deposits on the soil and on the water surface. The client did not want any analytical tests. According to the client statement, the substance was considered as stable in water for 96 hours but not soluble.

Sublethal observations / clinical signs:

Overview of test results

	After 24 hrs	After 48 hrs	After 72 hrs	After 96 hrs
LC0 (mg/l)	220	100	100	100
LC50 (mg/l)	> 1000	220 - 500	220 - 500	220 - 500
LC100 (mg/l)	not determined	1000	1000	1000

Conclusions:

Disregarded study

Executive summary:

The short-term toxicity to fish of the test item has been investigated using zebrafish (Brachydanio rerio). The experiment was conducted at the nominal concentrations of 0, 100, 220, 500 and 1000 mg/l. The test batches showed a strong turbidity with substance deposits on the soil and on the water surface; however, the client did not ask for any analytical tests. According to the client statement, the substance was considered as stable in water for 96 hours but not soluble.

The LC50 resulted to be above the solubility limit of the test substance in water. Because of the strong turbidity of the test water through the test substance, the symptom observation was limited. In all the tested concentrations an impairment of the swimming behavior, the respiration as well as a changed behavior was observed.

Discussion and conclusion

Although in the study was concluded that the LC50 (96h) was higher than the limit of solubility in the test medium, this cannot be proved without the analytical support and without the actual concentrations recording. Lethal effects, impacting the 50 % of tested population, were recorded between 220 and 500 mg/l. They were attributed to the low solubility of the substance, however it cannot be definitively confirmed.

Additional information

The short-term toxicity to fish of the test item has been investigated using zebrafish (Brachydanio rerio). The experiment was conducted at the nominal concentrations of 0, 100, 220, 500 and 1000 mg/l. The test batches showed a strong turbidity with substance deposits on the soil and on the water surface; however, the client did not ask for any analytical tests. According to the client statement, the substance was considered as stable in water for 96 hours but not soluble.

The LC50 resulted to be above the solubility limit of the test substance in water. Because of the strong turbidity of the test water through the test substance, the symptom observation was limited. In all the tested concentrations an impairment of the swimming behavior, the respiration as well as a changed behavior was observed.

Although in the study was concluded that the LC50 (96h) was higher than the limit of solubility in the test medium, this cannot be proved without the analytical support and without the actual concentrations recording. Lethal effects, impacting the 50 % of tested population, were recorded between 220 and 500 mg/l. They were attributed to the low solubility of the substance, however it cannot be definitively confirmed.

A second experiment is available of Fluorescent Brightener 371. The short-term toxicity to fish of the test item has been investigated using Leuciscus idus melanotus. The experiment was conducted at the nominal concentrations of 0, 1, 10, 100 and 500 mg/l. The test substance was dispersed in test water by ultra-Turrax stirrer; the substance was distributed evenly with a glass rod. The uniform distribution was constant throughout the experimental period.

During the 96-hour experimental period, no fish died in any of the tested concentration groups. The behavior was normal in all experimental groups and did not differ from the of control. At the concentration of 500 mg/l, the section of the animals killed at the end of the experiment gave a yellowish discoloration of the gail fluid, in comparison with the control fish.

Although the test can be considered as sufficientely documented and meeting generally accepted scientific principles, it cannot be considered as acceptable for assessment because the content of Fluorescent Brightener 371 in the lot tested was very limited. Therefore, it has been here reported only for completeness sake.