17-acetoxy-1β,2β-methanopegna-4,6-diene-3,20-dione

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:

15 Apr - 03 Sep 1998

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

No analytical measurement but the available data on the stability of the substance in water indicate stability over the time of exposure.

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Remarks:

TOC

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: 55.6 mg of the test substance were dissolved in 500 mL of tap water under constant stirring. This mixture was adjusted to pH 7.0 by adding 1 N HCI (approximately 0.3 mL) and then filtered. This filtrate was used for the test.
- Eluate: no
- Differential loading: yes
- Controls: yes, test medium control

Test organisms (species):

Daphnia magna

Test type:

semi-static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Test temperature:

21.0 - 21.2 °C

pH:

7.6 - 8.7

Dissolved oxygen:

7.5 - 8.6 mg/L

Nominal and measured concentrations:

nominal concentration: 100 mg/L
measured concentration: 1.2 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: 100 mL
- Volume of solution: 50 mL test solution and the dilution water
- No. of organisms per vessel: 20 (age: 1-25 hours)
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4
One additional test vessel for the test concentration and the control group was used without Daphnia for the measurements of pH, temperature and oxygen content.

TEST MEDIUM / WATER PARAMETERS
- Chlorine: no
- metal: no
- other substance: no

OTHER TEST CONDITIONS
- Photoperiod: 12 h light, 12 h dark

Reference substance (positive control):

no

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 1.2 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

- Immobilisation of control: 10% (is within the limit accepted by the OECD-Guideline)
- Immobilisation with test substance: 0%
The concentration of test solution was 1.2 mg/L at 0 h and < 1 mg/L at 48 hours (calculated on the basis of TOC).

The test temperature was in the range of 21.0 °C to 21.2°C.
The pH was 7.6 to 8.7, the oxygen content was between 7.5 mg/L and 8.6 mg/L.

The results of the TOC analysis indicate a loss of the compound. However, the low concentration of total organic carbon is close to the method detection limit of about 1.0 mg/L. Therefore, the difference in TOC after 0 hours (1.2 mg/L) and 48 hours (<1 mg/L) can possibly be attributed to a methodological problem.

 

Validity criteria for the measurement of the daphnia toxicity

Target condition according to guideline:	Actual condition according to the study:	Validity criteria met:
In the control, including the solubilising agent, not more than 10 % of the daphnids should have been immobilized. (Not more than 10 % of the control daphnids should show immobilisation or other signs of disease or stress, for example, discoloration or unusual behaviour such as trapping at surface of water)	Immobilization of control: 10%	Yes
The dissolved oxygen concentration at the end of the test should be </= 3 mg/L in control and test vessels.	The dissolved oxygen concentration should be between 7.5 and 8.6 mg/L in control and test vessels at the end of the test.	Yes
The concentration of the test item shall be maintained to within 80% of the initial concentration throughout the study. The maintenance of concentration is proved by analytical measurements	TOC: concentration 1.2 mg/L (beginning), < 1 mg/L (LOD, end)	Yes
A limit test may be performed at 100 mg/L of the test substance in order to demonstrate that the EC50 is greater than this concentration. The limit test should be performed using 20 daphnids, with the same number in the control. If the percentage of immobilisation exceeds 10% at the end of the test, a full study should be conducted.	A test solution of 100 mg/L was prepared with 20 daphnia, 1.2 mg/L of the test substance could be dissolved. At the end of the test, the test substance was < 1 mg/L (LOD).	Yes, when taking results from other studies into account.

 

 

Validity criteria fulfilled:

yes

Remarks:

See 'Any other information on results incl. tables'

Conclusions:

EC50 (48 h) > 1.2 mg/L

Executive summary:

The study was conducted to evaluate the acute toxicity of the test substance to Daphnia magna. The study was conducted in accordance with the OECD Guideline for the Testing of Chemicals No. 202 "Daphnia sp., Acute Immobilization Test and Reproduction Test, Part I".The EC 50 (48 h) is >1.2 mg/L.

The results of the TOC analysis indicate a loss of the compound. However, the low concentration of total organic carbon is close to the method detection limit of about 1.0 mg/L. Therefore, the difference in TOC after 0 hours (1.2 mg/L) and 48 hours (<1 mg/L) can possibly be attributed to a methodological problem. However, the hydrolytic stability has been determined (see 5.1.2 Hydrolysis). Furthermore, the study on acute toxicity to fish (see 6.1.1 Short-term toxicity) indicates that the substance concentration remains constant over 96 hours, monitored by the more specific HPLC-UV method. Therefore, the measured initial concentration is considered to be relevant. The EC 50 (48 h) is >1.2 mg/L.

Description of key information

The study was conducted to evaluate the acute toxicity of the test substance to Daphnia magna. The study was conducted in accordance with the OECD Guideline for the Testing of Chemicals No. 202 "Daphnia sp., Acute Immobilization Test and Reproduction Test, Part I".The EC 50 (48 h) is >1.2 mg/L.

The results of the TOC analysis indicate a loss of the compound. However, the low concentration of total organic carbon is close to the method detection limit of about 1.0 mg/L. Therefore, the difference in TOC after 0 hours (1.2 mg/L) and 48 hours (<1 mg/L) can possibly be attributed to a methodological problem. However, the hydrolytic stability has been determined (see 5.1.2 Hydrolysis). Furthermore, the study on acute toxicity to fish (see 6.1.1 Short-term toxicity) indicates that the substance concentration remains constant over 96 hours, monitored by the more specific HPLC-UV method. Therefore, the measured initial concentration is considered to be relevant. The EC 50 (48 h) is >1.2 mg/L.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

EC50

Effect concentration:

> 1.2 mg/L