(6R-trans)-7-amino-3-methyl-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid

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

Study period:

22 February 2010-24 February 2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: This study has been performed according to OECD and/or EC guidelines and according to GLP principles

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Report date:

2010

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Deviations:

no

Test guideline 3

Qualifier:

according to guideline

Guideline:

ISO 6341 (Water quality - Determination of the Inhibition of the Mobility of Daphnia magna Straus (Cladocera, Crustacea))

Deviations:

no

Test guideline 4

Qualifier:

according to guideline

Guideline:

other: Guidance document on aquatic toxicity testing of difficult substances and mixtures, OECD series on testing and assessment number 23, December 14, 2000

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

(6R-trans)-7-amino-3-methyl-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid

EC Number:

244-870-1

EC Name:

(6R-trans)-7-amino-3-methyl-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid

Cas Number:

22252-43-3

Molecular formula:

C8H10N2O3S

IUPAC Name:

7-amino-3-methyl-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid

Details on test material:

- Name of test material (as cited in study report):7-ADCA
- Substance type:White powder
- Physical state: Solid
- Analytical purity:99.0%
- Lot/batch No.:D212013
- Expiration date of the lot/batch:28 February 2011 (retest date)
- Stability under storage conditions: Stable
- Storage condition of test material:In refrigerator (2-8°C) in the dark
- Stability in water: Not indicated
- Solubility in water: 0.1% (20°C)

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

Samples for possible analysis were taken from all test concentrations and the control according to the schedule below. In addition, the filter used for preparation of the test solutions was retained for possible analysis of the residue.
Frequency: at t=0 h and t=48 h
Volume: 2 ml from the approximate centre of the test vessels
Storage: Samples were stored in a freezer until analysis
At the end of the exposure period, the replicates were pooled at each concentration before sampling.

Test solutions

Vehicle:

no

Details on test solutions:

The batch of 7-ADCA tested was a white powder with a purity of 99.0% and not completely soluble in test medium at the initial loading rate prepared.

Preparation of test solutions started with a loading rate of 100 mg/l applying a five-minute treatment period with ultrasonic waves followed by 2 days of magnetic stirring to reach maximum solubility of the test substance in the test medium. The resulting aqueous mixture was filtered through a 0.45 µm membrane filter (Whatman). The clear and colourless filtrate was used as the highest test concentration after pH had been adjusted from 5.9 to 6.5 using 1N NaOH (Merck, Darmstadt, Germany). The lower test concentrations were prepared by subsequent dilutions of the filtrate in test medium.

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna (Crustacea, Cladocera) (Straus, 1820)
- Source: In-house laboratory culture with a known history.
- Age at study initiation: < 24 hours
- Method of breeding: With newborn daphnids, i.e. less than 3 days old, by placing about 250 of them into 5 liters of medium in an all-glass culture vessel.
- Feeding during test: No

Study design

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Test conditions

Hardness:

180 mg/l expressed as CaCO3

Test temperature:

between 19.3 and 20.0°C

pH:

between 6.6-7.6

Dissolved oxygen:

Between 8.8-9.2 mg/l

Nominal and measured concentrations:

Nominal concentrations: 0-0.1-1.0-10-100 % filtered solution prepared at a loading rate of 100 mg/l.
Measured concentrations:
Samples taken from the filtered solution prepared at a loading rate of 100 mg/l were analysed. Although the initial loading rate was not observed to be completely dissolved actual concentrations were in agreement with nominal during the test period (97-98%). No explanation for this apparent contradiction could be given. Given these analytical results effect parameters were based on the initially measured and stable concentration of 98 mg/l.

Details on test conditions:

- Type (delete if not applicable): open
- Material, size, headspace, fill volume: glass, 100 ml, normal headspace
- Aeration: no
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4 for the highest concentration, 2 for the lower test concentrations
- No. of vessels per control (replicates): 4
TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Adjusted ISO medium: the following chemicals (analytical grade) are dissolved in tap water purified by Reverse Osmosis (RO-water, GEON Waterbehandeling, Berkel-Enschot, The Netherlands):
Macro salts: CaCl2.2H2O : 211.5 mg/l
MgSO4.7H2O: 88.8 mg/l
NaHCO3 : 46.7 mg/l
KCl : 4.2 mg/l
The hardness: 180 mg/l expressed as CaCO3 and the pH: 7.7 ± 0.3.
- Culture medium different from test medium: yes, for culturing M7 medium is used
OTHER TEST CONDITIONS
- Adjustment of pH: The clear and colourless filtrate had been adjusted from 5.9 to 6.5 using 1N NaOH (Merck, Darmstadt, Germany)
- Photoperiod: 16 hours photoperiod daily
EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : EC50 t=24 and t=48 h
TEST CONCENTRATIONS
- Spacing factor for test concentrations: 10
- Test concentrations:0, 0.1, 1.0, 10 and 100% of a filtered solution prepared at a loading rate of 100 mg/l

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

> 98 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

mobility

Effect concentrations 2

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 98 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

Behavioural abnormalities: no
- immobility of control: 5% immoblility in control
- Other adverse effects control: no
No acute immobilisation was observed at any concentration tested.

Results with reference substance (positive control):

- Results with reference substance valid? yes
The 24h-EC50 was 0.75 mg/l with a 95% confidence interval between 0.56 and 1.0 mg/l.
The 48h-EC50 was 0.36 mg/l with a 95% confidence interval between 0.28 and 0.49 mg/l.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

Under the conditions of the present study 7-ADCA did not induce acute immobilisation of Daphnia magna at 98 mg/l after 48 hours of exposure (NOEC).
The 48h-EC50 was >98 mg/l.