Alkanoic acid and polyoxomolybdate borate alkanoate clusters

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:

16 February 2017 - 12 June 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

April 2004

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

dated 14 January 2016

Analytical monitoring:

not specified

Details on sampling:

The test tubes were pooled for chemical analyses according to the following protocol:
- In fresh solutions: at the beginning of the test (T = 0h) and at the end of the test (T=48h)
- for the Control (i.e. filtered daphnids test medium), and at the lowest, the highest concentrations and a concentration around the expected EC50 concentration.
All the WAF solutions were analysed taken directly from the starting solutions without daphnids.

Vehicle:

no

Details on test solutions:

As the test item is not soluble in the test medium according to the sponsor, a special solubilisation protocol was carried out before the experimentation. This method consisted in stirring each test item nominal concentrations in the daphnia test medium during 24 hours. The test solutions were then filtered through a membrane filter to remove suspended particles: solutions obtained are named WAF (Water Accommodated Fraction).

Test organisms (species):

Daphnia magna

Details on test organisms:

Daphnia magna Straus, clone number 5, from at least the third generation (i.e. the third brood) obtained with a non-cyclic parthenogenesis reproduction.
The daphnids breeding was carried out in closed bottles placed in a climatic chamber free from any toxic vapour and in medium M4.
Daphnids used in this experimentation were previously filtered in order to obtain animals from a size between 560 µm and 800 µm (corresponding to daphnids less than 24 hours old).

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

270 mg/L of CaCO3 (test medium M4)

Test temperature:

20.0 +/- 0.1 degrees Celsius

pH:

7.2 - 8.3

Dissolved oxygen:

9.2 mg/L

Nominal and measured concentrations:

nominal concentrations: 0, 10.0, 19.0, 36.1, 68.6, 130.3, 247.6 mg/L

Details on test conditions:

- Test carried out in darkness.
- 24 h hour stirring each test item nominal concentrations in test medium.
- Then, all solutions plus control (algae test medium) were filtered through a membrane filter (cellulose acetate 0.45 µm batch G9952942) to remove suspended particles: solutions obtained were named WAF (Water Accommodated Fraction).
- Animals were not fed during testing.

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

130.7 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Remarks on result:

other: [108.7- 160.2]

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

215.6 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Remarks on result:

other: [169.7 - 317.3]

Details on results:

No sign of stress was observed on the mobile daphnids after 48 hours of exposure to the highest concentration.

Results with reference substance (positive control):

The last toxic response obtained on the reference item K2Cr2O7 (February 16, 2017) gives an EC50-24h of 1.11 mg/L (1.01 – 1.22), indicating that the daphnids sensitivity is correct (within the accepted interval of 0.6 – 2.1 mg/L fixed by the International Standard ISO 6341 December 2012 as mentioned in the OECD 202 Guideline) and in accordance with historical data obtained by the laboratory.

Reported statistics and error estimates:

The raw data could permit to calculate the EC50 with the software Minitab 17.2.4.

Daphnids immobilisation:

Nominal test item concentration in mg/L	Number of daphnids exposed at the start	Immobilised daphnids (%) at 24h	Immobilised daphnids (%) at 48h
Control	20	0 (0%)	0 (0%)
10.0	20	0 (0%)	0 (0%)
19.0	20	0 (0%)	0 (0%)
36.1	20	1(5%)	1 (5%)
68.6	20	0 (0%)	0 (0%)
130.3	20	0 (0%)	8 (40%)
247.6	20	15 (75%)	20 (100%)

Validity criteria fulfilled:

yes

Conclusions:

The results obtained for the test item in the experimental conditions of the test give:
EC50 (24h) = 215.6 mg/L [169.7 - 317.3]
EC50 (48h) = 130.7 mg/L [108.7 - 160.2]

Description of key information

The results obtained for the test item in the experimental conditions of an OECD 202 test give:

EC50 (24h) = 215.6 mg/L [169.7 - 317.3]

EC50 (48h) = 130.7 mg/L [108.7 - 160.2]

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

130.7 mg/L