Dipotassium propanedioate

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:

13.02-09.03.2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2018

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Dipotassium propanedioate

EC Number:

820-064-0

Cas Number:

13095-67-5

Molecular formula:

C3H2K2O4

IUPAC Name:

Dipotassium propanedioate

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

The analytical verification of test item concentrations in daphnid test medium was done by analysing the content of Dipotassium malonate in the samples during the test. Analytical samples were analysed from the test item concentration and control at test start and 48 hours from aged solutions.

Test solutions

Vehicle:

no

Details on test solutions:

- Test medium: reconstituted test water consisting of analytical grade salts dissolved in purified water (ISO test water)
- pH-value of the control (untreated test medium): 7.42
- dissolved oxygen concentration: 9.4 mg/L
- total hardness: 13°dH (232 mg/L as CaCO3)

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

- Daphnia magna Straus, Clone V, max. 24 hours old

Study design

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Post exposure observation period:

none

Test conditions

Hardness:

total hardness 140 - 250 mg/L (as CaCO3), corresponding to 7.8 - 14°dH

Test temperature:

18.9 – 19.5 °C

pH:

7.42 – 7.77

Dissolved oxygen:

≥ 9.0 mg/L

Salinity:

/

Conductivity:

not specified

Nominal and measured concentrations:

Nominal Concentration of the test item (100 mg/L, 0h fresh and 48h aged): 100 mg/L
Final Concentration µg/mL: 98.9 (0h fresh) and 96.2 (48h aged)

Details on test conditions:

TEST SYSTEM
- Test vessel: 100 mL glass vessels
- Type: covered with a glass plate
- Fill volume: ca. 50 mL
- Aeration: none
- No. of organisms per vessel: 20
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: reconstituted test water consisting of analytical grade salts dissolved in purified water (ISO test water)

OTHER TEST CONDITIONS
- Photoperiod: 16 hours light / 8 hours darkness daily
- Light intensity: not specified

EFFECT PARAMETERS MEASURED (with observation intervals if applicable): immobilisation.

Reference substance (positive control):

yes

Remarks:

potassium dichromate (1.00 mg/L, 2.00 mg/L)

Results and discussion

Effect concentrations

Effect concentrations 1

Key result

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: immobilisation

Effect concentrations 2

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: immobilisation

Details on results:

- Validity Criteria of the Study:
-- Control immobilisation: The percentage of immobilisation should be ≤ 10 %. In this study the control immobilisation was 0 %
-- Oxygen concentration: The dissolved oxygen concentration at the end of the test should be ≥ 3 mg/L in all test units. In this test, the dissolved oxygen concentration at the end of the test was ≥ 9.0 mg/L

- Biological Results:
-- After 24 hours of exposure no immobilisation was observed in the control and at 100 mg/L
-- After 48 hours of exposure no immobilisation was observed in the control and at 100 mg/L
-- No behavioural changes could be observed

- Analytical Results:
The measured content of dipotassium malonate was 99% of nominal and the aged measured content was 96% of nominal. Since the content of dipotassium malonate in the samples was between 80 and 120% of nominal the toxicological endpoints were evaluated using nominal concentrations.

Results with reference substance (positive control):

The results indicate an EC50 (24 h) of the reference item potassium dichromate between 1.00 and 2.00 mg/L.
Since the results are in accordance with the requirements of the OECD guideline 202 and fall within the historical data generated with the reference item at the testing facility, the daphnids were suitable for the determination of the toxicological effects of the test item.

Reported statistics and error estimates:

All toxicological endpoints were evaluated using nominal concentrations.

Any other information on results incl. tables

EC₅₀and NOEC-values of daphnids exposed to the test item evaluated using nominal concentrations

Endpoint	Dipotassium malonate [mg/L]
	24 h	48 h
NOEC	100	100
EC50	> 100	> 100
95 % confidence limit of EC50	-	-

- not applicable

Analytical Results: Determined concentration of Dipotassium malonate

Dipotassium malonate nominal [mg/L]	Sampling [h]		analyte
			[mg/L]		% of nominal
Control	0 fresh		n.d.		-
	48 aged		n.d.		-
100	0 fresh		98.8		99
	48 aged		96.4		96

- = not calculated; n.d. = not detectable; LOQ = 0.400 mg/L Dipotassium malonate

Results of the test, 24 h values

	Nominal test item concentration [mg/L]
	Control	100
	Immobilised daphnids after 24 h
Replicate 1	0	0
Replicate 2	0	0
Replicate 3	0	0
Replicate 4	0	0
Σ	0	0
%	0	0

Results of the test, 48 h values

	Nominal test item concentration [mg/L]
	Control	100
	Immobilised daphnids after 48 h
Replicate 1	0	0
Replicate 2	0	0
Replicate 3	0	0
Replicate 4	0	0
Σ	0	0
%	0	0

Results of the toxic reference test

K2Cr2O7	24 h			48 h
[mg/L]	1.00	2.00		1.00		2.00
	immobilised daphnids
Replicate 1	2		5	5	5
Replicate 2	0		5	2	5
Replicate 3	1		5	5	5
Replicate 4	2		5	5	5
S	5		20	17	20
%	25		100	85	100

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

According to the results of the test, the EC50 (48 h) for immobilisation was assumed to be > 100 mg/L (nominal). The corresponding NOEC (48 h) was 100 mg/L (nominal).

Executive summary:

The objectives of this study were to determine the immobilisation effect of the test item Dipotassium malonate on the water flea Daphnia magna under worst-case exposure conditions after the exposure to test solutions and observation of immobilisation after 24 and 48 hours of exposure under static conditions. The study was performed according to OECD test guideline 202 (2004) and in compliance to GLP.

The test was performed as a static limit test with twenty test organisms per treatment (4 replicates of 5 test organisms each). The duration of the test was 48 hours. Endpoints reported are the EC₅₀and the NOEC after 24 and 48 hours.

Following a static non-GLP range-finding test a static limit test with the nominal concentration 100 mg/L and control was performed. Temperature, pH-value and oxygen concentration of the test solutions measured after 0, 24 hours aged and 48 hours are reported. Hardness of the test medium (untreated control) was measured on the day of application.

Analytical samples taken at 0 hours (initial value) and 48 hours from aged test solutions were analysed from control and the test item concentration.

Due to a lack of immobilisation, the values for EC₅₀were not determined statistically. The NOEC was established based on the highest concentration at which the immobilisation is not higher than the allowed control immobilisation (≤ 10 % immobilisation).

All validity criteria were fulfilled.

According to the results of the test, the EC₅₀ (48 h) for immobilisation was assumed to be > 100 mg/L (nominal). The corresponding NOEC (48 h) was 100 mg/L (nominal).