9β,11β-epoxy-17,21-dihydroxy-16β-methylpregna-1,4-diene-3,20-dione

Short-term toxicity to aquatic invertebrates

Administrative data

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2016

Report date:

2016

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Test guideline 2

Qualifier:

according to guideline

Guideline:

other: UNI EN ISO 6341:2004 “Determination of the inhibition of the mobility of Daphnia magna Straus (Cladocera, Crustacea)”.

Test guideline 3

Qualifier:

according to guideline

Guideline:

other: Council Regulation EC 440/2008 (C.2).

Test guideline 4

Qualifier:

according to guideline

Guideline:

other: OECD Series on Testing and Assessment No 23 - Guidance Document On Aquatic Toxicity Testing Of Difficult Substances And Mixtures ENV/JM/MONO(2000)6.

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

9β,11β-epoxy-17,21-dihydroxy-16β-methylpregna-1,4-diene-3,20-dione

EC Number:

213-563-4

EC Name:

9β,11β-epoxy-17,21-dihydroxy-16β-methylpregna-1,4-diene-3,20-dione

Cas Number:

981-34-0

Molecular formula:

C22H28O5

IUPAC Name:

17,21-dihydroxy-16-methyl-9,11-epoxypregna-1,4-diene-3,20-dione

Test material form:

solid: particulate/powder

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: 14192-00816
- Expiration date of the lot/batch: January 26, 2018
- Purity test date: 98.6

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: The test item is stored at room temperature at the dark,
following Test Substance Data Sheet (TSDS) supplied by the Sponsor.

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

The study was performed on the freshwater crustacean Daphnia magna Straus. A strain of this species was supplied by MicroBioTests Inc., Belgium in December 2011 (batch number: DM290911).
Since that time, the clone has been bred in the laboratories of the Test Facility under conditions identical to those of the test, with regard to temperature, light and water quality
(see below), so that no acclimation was needed prior to testing.
It was daily fed with a fixed amount of the laboratory cultured green algae
Pseudokirchneriella subcapitata (formerly Selenastrum capricornutum) and with a
suspension of the yeast Saccharomyces cerevisiae.
At the test start the organisms used in the test were less than 24 hours old and were not first
brood progeny.

Study design

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Test conditions

Test temperature:

The incubation temperature was continuously monitored during the course of the study by a PT100 probe installed in the environmental test chamber. It was in the range 20.0 – 20.1°C with a mean value of 20.0 °C and a standard deviation of 0.02 °C. The temperature range provided by OECD guideline is 20 ± 2°C. The temperature values during the test were within the provided range and did not vary more than 1°C during the test period.

pH:

The pH of the fresh test media was 7.62 for negative control and 7.66 for the only test item solution at 1.0 mg/L. The pH did not vary by more than 0.02 unit during the test period, as required in the mentioned guideline.

Dissolved oxygen:

The dissolved oxygen concentration in the negative control and in the test item solution was always higher than 5.0 mg/L (Table 2) according to OECD Guideline N 202 that provides a minimum oxygen concentration of 3.0 mg/L.

Nominal and measured concentrations:

CaCl2 × 2H2O : 2.0 mmol/L (= 294.0 mg/L)
MgSO4 × 7H2O : 0.5 mmol/L (= 123.3 mg/L)
NaHCO3 : 0.771 mmol/L (= 64.8 mg/L)
KCl : 0.078 mmol/L (= 5.8 mg/L)
Water Hardness : 140 - 250 mg/L as CaCO3
Alkalinity : 0.8 mmol/L
Ratio of Ca : Mg = 4 : 1 (based on molarity)
Na : K = 10 : 1 (based on molarity)

Results and discussion

Effect concentrations

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 1 mg/L

Nominal / measured:

nominal

Remarks on result:

other: The Daphnia were exposed at only one nominal concentration, 1.0 mg/L, corresponding to the maximum solubility obtainable in test medium and in test conditions.

Details on results:

In the negative control 0% of immobilization was observed and no daphnid was trapped on the test water surface or showed other signs of disease or stress (Table 3). These values comply with the validity criteria of the test, that provides a maximum immobilization or a maximum number of daphnids showing distress signs of 10% in the negative control at the end of the test.
The obtained experimental results allowed to determine the EC0, EC100, EC50 and NOEC values at 24 and 48 h.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The acute toxicity of test item BETA-METHYLEPOXY was tested on Daphnia magna under static conditions.
The EC0, the EC100, the EC50 value and the NOEC at 24 and 48 hours were assessed.
The biological results were referred to nominal concentration of test item.