Pyridine-2-carbaldehyde oxime

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:

2017-05-30 - 2017-06-01 (experimental phase)

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

Report date:

2017

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

OECD Guideline for Testing of Chemicals No. 202, adopted 13. Apr. 2004: ”Daphnia sp., Acute Immobilisation Test“

Deviations:

yes

Remarks:

see "Any other information on materials and methods incl. tables"

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Version / remarks:

Council Regulation (EC) No. 440/2008, Method C.2. “Daphnia sp. Acute Immobilisation Test”, adopted 30. May 2008

Deviations:

yes

Remarks:

see "Any other information on materials and methods incl. tables"

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Pyridine-2-carbaldehyde oxime

EC Number:

212-849-6

EC Name:

Pyridine-2-carbaldehyde oxime

Cas Number:

873-69-8

Molecular formula:

C6H6N2O

IUPAC Name:

pyridine-2-carbaldehyde oxime

Test material form:

solid: particulate/powder

Specific details on test material used for the study:

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: The test item was stored in a closed vessel at room temperature (20 ± 5°C).

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 0, 2.2, 4.6, 10, 22, 46, 100 mg/L
- Sampling method: not specified. Samples for the analytical determination were taken at test start and test end.
- Sample storage conditions before analysis: not specified

Test solutions

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: A stock solution containing 100 mg/L (real load 100.2 mg/L) in dilution water was prepared. The solution was used as highest treatment and also for preparation of the solutions of the lower treatments.
- Controls: Blank control were 4 vessels, each containing 20 ± 5 mL dilution water and 5 Daphnia
- Evidence of undissolved material (e.g. precipitate, surface film, etc.): none stated

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

- Source: Daphnia magna is bred in the LAUS GmbH throughout the year. The animals are kept for the use in toxicity tests. They multiply by parthenogenesis, thus being genetically identical.
- Age of parental stock (mean and range, SD): In-house breeding since 2007-09-27
- Husbandry: The husbandry is performed similar to the method described in EN ISO 6341
Vessels: preserving glasses, nominal volume 2 L
Medium: M4-Medium (recipe of ELENDT)
Food: unicellular green algae (Desmodesmus subspicatus)
Medium renewal: twice a week
Photo period: 16/8 hours, using neon tubes
Temperature: 20 +/- 2 °C
- Feeding during test: no

ACCLIMATION
- Acclimation period: none
- Acclimation conditions (same as test or not): Not the same, but switching from M4-medium (husbandry) to Dilution water (test) has been shown not to cause any detrimental effects for test Daphnia.

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Post exposure observation period:

no

Test conditions

Hardness:

2.502 mmol/L; 250 mg CaCO3/L

Test temperature:

19.7 - 22.1 °C

pH:

7.7 at test start
7.8 - 7.9 at test end

Dissolved oxygen:

8.9 - 9.0 at test start
7.7 - 8.1 at test end

Nominal and measured concentrations:

Nominal: 0, 2.2, 4.6, 10, 22, 46, 100 mg/L
Measured: t0h = 0, 2.05, 4.42, 9.40, 21.47, 44.64, 101.89 mg/L; t48h = 0, 2.33, 4.86, 10.20, 23.75, 49.47, 106.97 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: glass beakers, nominal volume 50 mL, tall shape
- Type (delete if not applicable): open
- Aeration: no
- Medium renewal: none
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Deionised water with an enrichment of certain minerals (dilution water as demanded in the guidelines) was used in the test.
Dilution water specification:
Parameter Concentration in mg/L
CaCl2*2H2O 293.80
MgSO4*7H2O 123.30
NaHCO3 64.80
KCl 5.80
Exact values ae recorded in the raw data. After preparation, the dilution water was aerated and the pH was measured. The pH was 7.6.
- Culture medium different from test medium: yes

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16/8 hours, using neon tubes

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : After 24 and 48 hours, the immobilised Daphnia were counted. The pH and the concentration of dissolved oxygen were measured at the beginning and at the end of the test.

VEHICLE CONTROL PERFORMED: no

Reference substance (positive control):

yes

Remarks:

Potassium dichromate K2Cr2O7 (CAS No. 7778-50-9) was used as positive control in a current reference study to assure that the test conditions are reliable.

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

51 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Effect concentrations 2

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

21 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Effect concentrations 3

Duration:

48 h

Dose descriptor:

LOEC

Effect conc.:

22 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Effect concentrations 4

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

10 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

- Behavioural abnormalities: none stated
- Mortality of control: 0%
- Other adverse effects control: none stated
- Abnormal responses: none stated
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: no
- Effect concentrations exceeding solubility of substance in test medium: no

Results with reference substance (positive control):

Potassium dichromate K2Cr2O7 (CAS No. 7778-50-9) was used as positive control in a current reference study to show that the results of the current study are reliable. The 24h-EC50 value was determined to be 1.6 mg/L. The fits showed sufficient statistical correspondence of the data with the dose-response-equation. The values were within the range of 0.6 - 2.2mg/L as demanded in the OECD guideline and therefore the test conditions are reliable.

Reported statistics and error estimates:

The estimation of the biological results was accomplished using the software ToxRat® Professional, version 3.1.2. 95% confidence interval could not be determined.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The study was conducted under GLP according to OECD guideline 202 and EU method C.2 on the registered substance itself. The method is to be considered scientifically reasonable with no deficiencies in documentation and without deviations which may have impact on the validity of the study. The validity criteria were met. Hence, the results can be considered as reliable to assess the toxicity of pyridine-2-carbaldehyde oxime towards daphnids.
The toxicity against Daphnia magna was tested in a static test at nominal concentrations of 2.2, 4.6, 10, 22, 46 and 100 mg/L. The three highest concentrations showed significant toxicity. None of the animals were immobilised in the blank control.
The measured concentrations were in a range of 93 - 108 % of the nominal concentration. Therefore, the determination of the biological results was based on the nominal concentration.
The following results were determined for the test item pyridine-2-carbaldehyde oxime (species: Daphnia magna):

LOEC = 22 mg/L
NOEC = 10 mg/L
EC50 = 21 mg/L

Based on these results, the test item does not need to be classified as acute toxic to the aquatic environment according to the Regulation (EC) No. 1272/2008. With regard to chronic toxicity, taking into account the facts that the test item is soluble in water, i.e. above the determined EC50 value, and not readily biodegradable, the test item should be classified as aquatic chronic Cat. 3.

Executive summary:

The acute toxicity of pyridine-2-carbaldehyde oxime was determined in a study according to OECD TG 202 under GLP.

Findings and Results:

The study was performed using 6 concentrations ranging from 2.2 to 100 mg/L nominal concentration. For each test concentration, 20 Daphnia were exposed to the test item for 48 hours in a static test system. After 24 and 48 hours, the immobilised Daphnia were counted.

The three highest concentrations showed significant toxicity. None of the animals were immobilised in the blank control.

Potassium dichromate K2C2O7 (CAS No. 7778-50-9) was used as positive control in a current reference study to assure that the test conditions are reliable.

At the beginning and at the end of the test, the content of the test item in the test solutions was determined using HPLC-UV-determination. The measured concentrations were in a range of 93 - 108 % of the nominal concentration. Therefore, the determination of the biological results was based on the nominal concentration.

The following results were determined for the test item pyridine-2-carbaldehyde oxime (species: Daphnia magna).

48h-NOEC = 10 mg/L

48h-LOEC = 22 mg/L

24h-EC50 = 51 mg/L

48h-EC50 = 21 mg/L