3,4-dihydro-2,5,7,8-tetramethyl-2-(4,8,12-trimethyltridecyl)-2H-benzopyran-6-ol

Long-term toxicity to fish

Administrative data

Endpoint:

fish, juvenile growth test

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Study period:

17.01.2001 - 11.07.2001

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2001

Report date:

2001

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 215 (Fish, Juvenile Growth Test)

Deviations:

yes

Remarks:

stocking density could not be kept at 4 fish per litre as the loading (1.2-2.0 g/l) could not be reached under these conditions

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

3,4-dihydro-2,5,7,8-tetramethyl-2-(4,8,12-trimethyltridecyl)-2H-benzopyran-6-yl acetate

EC Number:

231-710-0

EC Name:

3,4-dihydro-2,5,7,8-tetramethyl-2-(4,8,12-trimethyltridecyl)-2H-benzopyran-6-yl acetate

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

Samples for analytical determinations were taken from the new, freshly prepared test solution and from old test solutions just before renewal. The
samples were taken from the approximate centre of the test aquaria after mixing the medium and were kept at -10° to -30°C until analysis.

Test solutions

Details on test solutions:

A limit test with a test concentration of 100 mg/l nominal and a control (without the test item) was carried out. On each day of test medium renewal,
1000 mg of test item was weighed out. For the preparation of the fresh test solution, the test item was mixed and sonicated directly in the aquarium in 10 litre of test water for 30 minutes using an Ultraturrax T25.
The test medium of the test concentration and of the control was renewed every Monday, Wednesday and Friday throughout the 20-day exposure period. On these days, the medium was renewed by preparing a second series of test aquaria containing the respective new test solutions. The test
organisms were then transferred into the new media.

Test organisms

Test organisms (species):

Oncorhynchus mykiss (previous name: Salmo gairdneri)

Details on test organisms:

Fish were supplied for a commercial supplier in one batch and were all of a similar age and size. Fish were held in dechlorinated tap water under
similar conditions used in the test and fed daily a ration of 3% body weight with a commercially prepared trout food diet. Fish used in the
experiment were not fed 24 hours prior to initiation of the test. Quality of the fish was assessed during an acclimatisation period of at least 14 days in dechlorinated tap water.

Study design

Test type:

semi-static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

28 d

Test conditions

Hardness:

160 mg CaCo3/l

Test temperature:

13.1 - 15.0 °C

pH:

8.0 - 8.7

Dissolved oxygen:

= 60% of air saturation value

Nominal and measured concentrations:

nominal: 100 mg/l

Details on test conditions:

- Test system: Rainbow trout, 10 fish at each treatment level
- Test duration: 28 days
- Test design: Semi-static test at 13.1 - 15°C; test volume of 10 litres
- Test concentration: 100 mg test item/l (nominal)

Experimental conditions:

- Procedure: Semi-static system (renewal of test solutions on Monday, Wednesday and Friday each week)
- Light: Photoperiod: 16 hours light and 8 hours darkness, transition period of 30 minutes
- Test vessel: 20-litre glass aquaria with a test water volume of 10 litre, slightly aerated
- Test organisms per concentration: 10 fish per concentration and control
- Feeding: During the test period fish were fed at a rate of 4% of their body weight per day with a commercially prepared trout food diet

Results and discussion

Effect concentrations

Duration:

28 d

Dose descriptor:

NOEC

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Reported statistics and error estimates:

The statistical analysis of the control and the test concentration of 100 mg/l DL-alpha-Tocopheryl Acetate was based on growth rates for individual
fish. No significant difference between the growht rate of the fish in the control tanks in comparison to the growth rate of the fish in the
treatment with DL-alpha-Tocopheryl Acetate was detected (Student-t-test, alpha = 0.05, one-sided, smaller).

Any other information on results incl. tables

No mortality or sublethal effects, such as changes in swimming behaviour, respiratory function or pigmentation or loss of equilibrium were observed in the test fish in the control and the treatment of 100 mg/l (nominal) throughout the 28 day exposure period.

The mean weight of fish in the controls increased from 1.79g to 4.53g over the 28 day exposure period, i.e.by 253%, hence meeting the validity criteria of the Guideline. The tank-average specific growth rate was calculated for the control and the test concentration and was determined to be: 1.4272 and 1.4576, respectively.

The nominal concentrations of DL-alpha-Tocopheryl Acetate was 100 mg/l. Test solutions were analysed for DL-alpha-Tocopheryl Acetate. The measured concentrations of DL-alpha-Tocopheryl Acetate ranged from 48 to 206% of the nominal concentration in the new, freshly prepared test solutions and from 20 to 149% in the old test solutions taken just before renewal of test solutions. Thea mean measured concentration was 73 mg/l DL-alpha-Tocopheryl Acetate.

At every single determination, the concentration of DL-alpha-Tocopheryl Acetate was well above the water solubility of the test item (<0.8 mg/l). Hence, testing an emulsion at these high concentrations also covered the assessment of potential physical effects of the test item on the growth of juvenile rainbow trout.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

A nominal concentration of 100 mg/l DL-alpha-Tocopheryl Acetate showed no significant effect on the growth of juvenile rainbow trout after
28 days of exposure.