1-(5,6,7,8-tetrahydro-3,5,5,6,8,8-hexamethyl-2-naphthyl)ethan-1-one

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

14 September 1994 - 19 March 1996

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Results are used from Daphnia reproduction study carried out according the OECD Guideline and under GLP. Daphnia were fed during exposure. Results are after 3 days instead of 2.

Reason / purpose for cross-reference:

reference to same study

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Principles of method if other than guideline:

As the results were taken from the Daphnia reproduction study, the test animals were fed during the test

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Vehicle:

yes

Details on test solutions:

Dimethylformamide and 0.005% Tween 80 were used to prepare the stock solutions.
The final concentration of Tween 80 / DMF was 0.002% - 0.008 % is all test concentrations and in the solvent control.

Test organisms (species):

Daphnia magna

Details on test organisms:

<24 hours of age, defined clone 5

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

21 d

Remarks on exposure duration:

Total test lasted 21 days, first report after day 3 is used for this entry. Daphnia were fed daily.

Post exposure observation period:

none

Test temperature:

19.0-21.5°C

pH:

7.7-8.1

Dissolved oxygen:

8.1-9.2 mg O2/l

Nominal and measured concentrations:

The final concentration of Tween 80 / DMF was 0.002% - 0.008 % is all test concentrations and in the solvent control.
Concentrations (ug/l) nominal, ug/l measured day 0, measured day 3
62.5 60.2 45.3
125 120.4 101.2
250 224.7 175.8
500 460.0 352.1
1000 911.7 696.4

Details on test conditions:

Light=16 hours/day, about 500-2000 Lux; test medium=Elendt M7 aerated before use; no aeration during study; test medium renewed on exposure days 1 and 3; daily feeding of Daphnia with Scenedesmus subspicatus

Reference substance (positive control):

no

Duration:

3 d

Dose descriptor:

EC50

Effect conc.:

> 800 µg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: No effects in any test concentration after 3 days

Details on results:

After 3 days exposure no effects were observed in any of the test concentrations

Reported statistics and error estimates:

No statistics.

Validity criteria fulfilled:

yes

Remarks:

Criteria for acute immobilisation test: No effects on mobility or other were observed in the control and the oxygen concentrations remained above 3 mg/l

Conclusions:

The short-term EC50 was derived from a 21d-reproduction test with Daphnia magna, which were fed during the test. The report included results after 3 days. No effects were observed in any test concentration, so the 3d-EC50 (immobility) was above > 800 microgram/l.

Executive summary:

The impact of AHTN was assessed in a 21d-reproduction study with Daphnia magna according to OECD TG 202, part II and under GLP. The daphnids were fed daily. The results for day 0 to day 3 have been used to derive the acute EC50 for daphnia.

Tween80 and DMF were used to prepare the stock solutions. Test concentrations ranged from 55 to 800 microgram per liter (mean measured for day 0 and day 3).

No effects were observed in any of the tested concentrations. The oxygen concentration remained above 60% of the saturation level and the control mortality was below 10%, demonstrating that the test is valid.

Therefore the 72h-EC50 was above 800 ug/l (Remark: daphnids were fed).

Description of key information

The acute toxicity for Daphnia, derived from the reproduction test was 72h-EC50 > 800 µg/L. Several other studies on aquatic invertebrates were conducted. One of which determined a 96-h LC50 value of 0.61 mg/L for Nicotra spinipes, which was used as the key value.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

0.61 mg/L

Marine water invertebrates

Marine water invertebrates

Effect concentration:

0.61 mg/L

Additional information

The acute toxicity for Daphnia magna was derived from a 21d-reproduction study according to OECD TG 202, part II and under GLP (Rel. 2). The daphnids were fed daily. The results for day 0 to day 3 have been used to derive the acute EC50 for Daphnia.

No effects were observed in any of the tested concentrations. Therefore the 72h-EC50 was above 800 µg/L.

In the EU RAR a series of other short term toxicity tests on invertebrates was assessed (EU RAR 2008, Table 3.32). Most of them were qualified with Reliability 3 or 4, but two short term studies were considered as acceptable to be used for the classification: Acartia tonsa with 48h-LC50 = 0.71 mg/L (Wollenberger et al, 2003) and 96h-LC50 = 0.61 mg/L for Nitocra spinipes (Breitholz et al. 2003).

Of these results, the one for Nitocra spinipes is the lowest: LC50 is 0.61 mg/L.