Pregn-4-ene-3,20-dione, 21-(acetyloxy)-6-fluoro-11-hydroxy-16-methyl-, (6.alpha.,11.beta.,16.alpha.)-

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:

27 Oct - Nov 1998

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Qualifier:

equivalent or similar to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

GLP compliance:

no

Analytical monitoring:

yes

Remarks:

TOC analyzer

Details on sampling:

For the concentration analysis samples were taken from each test vessel with the test product at 0 hour and 48 hours.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: 100 mg test item were suspended in 1000 mL tap water under constant stirring for 24 hours. Thereafter, the solution was filtered through a glassfibre filter. The filtered solution was used as test solution.
- Eluate: no
- Differential loading: no
- Controls: yes, test medium control

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: water flea
- Source: Schering AG, Experimental Toxicology, Berlin, Germany
- Age: 24-25 hours
- Holding: Parent animals were kept in glass vessels in water of the same quality and temperature as under experimental conditions. The animals were continuously fed with a laboratory culture of microalgae, e.g. Chlorella vulgaris.
- Water: Normal tap water was used as dilution water, not polluted with harmful concentrations of chlorine, heavy metals or other substances, based on quarterly measurements

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Hardness:

251 mg/L (CaCO3)

Test temperature:

20.8 - 21.2 °C

pH:

control: beginning: 7.7, end: 8.6
saturated solution: beginning: 8.6, end: 9.1

Dissolved oxygen:

7.6 - 9.1 mg/L

Conductivity:

755 µs/sec

Nominal and measured concentrations:

nominal: control, 100 mg/L
mean measured concentration: below the detection limit (1 mg/L)

Details on test conditions:

I. Exposure conditions:
- 20 Daphnia were used for the test concentration and also for the control group, randomly distributed into groups of five
- Labeled 100 mL test vessel were used and filled with 45 mL of the test solution or tap water (control group) and 5 mL of the dilution water with the introduction of the Daphnia
- Experimental design: test was performed with 4 replicates of the test solution and the dilution water control with 5 Daphnia in each vessel
- Method of initiation: neonates were placed in prepared media
- Photoperiod: 12 h light : 12 h dark
- Aeration: none
- Feeding: None
- Criteria of effects: Immobilization and visual abnormalities

II Observations
- Immobilization and visual abnormalities were recorded at 24 and 48 hours

III. Hydrographical measurements:
- One additional vessel (measurement vessel) without Daphnia for each test and control solution, resp. was used for the measurements of pH, temperature and oxygen content
- pH, oxygen concentration and temperature were measured at 0 and at 48 hours

Reference substance (positive control):

no

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 1 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

mobility

Validity criteria for the measurement of the daphnia toxicity:

Target condition according to guideline:	Actual condition according to the study:	Validity criteria met:
Young daphnids, aged less than 24 hours at the start of the test, are exposed to the test substance at a range of concentrations for a period of 48 h.	Age of daphnids used: 24 - 25 h Exposure time: 48 h	Yes
In the control, including the control containing 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)	The control mortalities are below the 10 % value which is regarded as the limit for natural mortality. As the physico-chemical measurements show, the composition of the test water corresponds to the nominal values. The EC50 of the reference substance lies within the required range. Thus, the study conditions correspond to the standard.	Yes
Test concentrations: At least five test concentrations should be used. They should be arranged in a geometric series with a separation factor preferably not exceeding 2.2. The highest concentration tested should  preferably result in 100 % immobilization, and the lowest concentration tested should preferably give no observable effect.	Test concentrations used: 1 (limit tests) Test concentration separation factor: None as limit test	Yes (with acceptable deviation)

 

Validity criteria fulfilled:

yes

Remarks:

see "Any other information on results incl. tables"

Conclusions:

EC50 (48 h) > 100 mg/L (nominal)
EC50 (48 h) > 1 mg/L (measured TOC)

Executive summary:

The study was conducted as a limit test in agreement with OECD guideline no. 202 to assess the toxicity of Fluocortolon-A-Acetat towards Daphnia. 20 juvenile Daphnia magna were used for the test solution of Fluocortolon-A-Acetat and 20 Daphnia for the tap water control. The Daphnia were exposed for a period of 48 hours under static conditions. Immobilization was recorded at 24 hours and 48 hours. For the preparation of the test solution, a suspension with a nominal loading of 100 mg/L was stirred for 24 hours. This suspension was filtered through a glassfibre filter. The saturated solution obtained by this procedure was used. The organic carbon concentration of the test solution was analyzed with a TOC analyzer at the start of exposure and 48 hours thereafter. The mean concentration was below the detection limit (1 mg/L). The test temperature was in the range of 20.8 to 21.2 °C, the pH ranged between 7.7 and 8.6, and the oxygen concentration between 7.6 and 9.1 mg/L. The light/dark rhythm was adjusted to 12 hours/12 hours.

A 48h-EC50 > 1 mg/L was determined for Fluocortolon-A-Acetat towards Daphnia. No toxic effect could be determined up to a limit concentration of 100 mg/L (nominal).

This toxicity study is classified as acceptable and satisfies the guideline requirements for the acute daphnia study.

Description of key information

A study was conducted as a limit test in agreement with OECD guideline no. 202 to assess the toxicity of Fluocortolon-A-Acetat towards Daphnia. A 48h-EC50 > 1 mg/L was determined for Fluocortolon-A-Acetat towards Daphnia under static conditions. No toxic effect could be determined up to a limit concentration of 100 mg/L (nominal).

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

1 mg/L

Additional information

"Should read: > 1 mg/L"

The 48 h-EC50 to Daphnia magna is higher than a saturated solution of Fluocortolon-A-Acetat (<1 mg/L), determined by TOC analysis.