Sodium chlorodifluoroacetate

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:

From 9-10-2022 to 13-10-2022

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)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 87.79, 131.69, 197.53, 296.30, 444.44, 666.67 and 1000.0 mg/L along with the control group. The test concentration was spaced using a geometric factor of 1.5.
- Sampling method: During Range finding study study was conducted at the test concentrations of 0.01, 0.1, 1.0, 10.0, 50.0 and 100.0 mg/L.

Vehicle:

no

Remarks:

Based on the solubility test, the test item was soluble in the reconstituted water.

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: Stock solution was freshly prepared prior to exposure, by weighing required quantity of test item in a beaker; a small volume of reconstituted water was added and mixed well using a glass rod after soluble of test item, the test formulation was transferred into a measuring cylinder and the beaker was rinsed with reconstituted water and transferred again to the measuring cylinder. Rinsing process was repeated until the complete transfer of test contents and finally the volume was made up to require quantity by reconstituted water and stock solution was kept for stirring on magnetic stirrer to maintain homogeneity. Test medium of chosen concentration was prepared by dilution of stock solution.
- Controls: Positive control (potassium dichromate (K2Cr2O7) was tested in-house at least twice a year to demonstrate satisfactory test conditions).
- Concentration of vehicle in test medium: Reconstituted water with the pH 7.41 to 7.68 during dose range finding study and 7.18 to 7.69 during main study and total hardnes of 217.8 to 221.3 mg/L (as CaCO3) was maintained throughout the test condition during dose range finding study and main study.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna
- Age at study initiation (mean and range, SD): Young daphnids less than 24 hours old
- Source: Environmental and Molecular Toxicology Division, Department of Zoology, Karnataka University, Dharwad, Karnataka, India.
- Feeding during test
- Feeding: Daphnids were fed with live algal cells (Raphidocelis subcapitata) of 2 mL per liter during the acclimatization. No feeding was done during the test

ACCLIMATION
- Acclimation period: 48 hours
- Acclimation conditions: Daphnid were fed with live algal cells at the beginning and on Day 1 of acclimatization. Progenies produced on the first day were not used. Progenies produced on day two (Less than 24 hours old) are transferred into the test containers and these Daphnids were used for dose range finding as well as main study respectively.

Test type:

static

Limit test:

no

Total exposure duration:

48 h

Post exposure observation period:

None.

Hardness:

201.7 mg CaCO3/L

Test temperature:

20.7 - 20.8 ºC

pH:

7.24 to 7.33

Dissolved oxygen:

>8.11 mg/L

Nominal and measured concentrations:

87.79, 131.69, 197.53, 296.30, 444.44, 666.67 and 1000.0 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: glass beakers.
- Material, size, headspace, fill volume: capacity of 250 mL.
- Renewal rate of test solution (frequency/flow rate): Not applicable (static test).
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4
- No. of vessels per vehicle control (replicates): No applicable.

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: reconstituted water prepared as described in the OECD 202 guideline.
- Intervals of water quality measurement: Total hardness was analyzed prior to its use for exposure. Temperature, pH and dissolved oxygen were recorded at test initiation and at the beginning and at the
end of test in the treatments and in the control.

OTHER TEST CONDITIONS
- Adjustment of pH: No.
- Photoperiod: complete darkness was maintained (Except during clinical signs observation and renewal period)


EFFECT PARAMETERS MEASURED (with observation intervals if applicable): Each test vessel was observed for immobilized daphnids at 24 and 48 hours after the beginning of the test.

VEHICLE CONTROL PERFORMED: no

RANGE-FINDING STUDY
- Test concentrations: 0.01, 0.1, 1.0, 10.0, 50.0 and 100.0 mg/L
- Results used to determine the conditions for the definitive study: Based on results of the dose range finding study, the main study was conducted at the test concentrations of 87.79, 131.69, 197.53, 296.30, 444.44, 666.67 and 1000.0 mg/L along with the control group.

Reference substance (positive control):

yes

Remarks:

(Potassium dichromate)

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

- Behavioural abnormalities:
- Mortality of control: No mortality was observed over a period of 48 h in the control group.
- Abnormal responses: No clinical signs of toxicity or immobilization was observed in control group and at the tested concentrations of 87.79, 131.69, 197.53, 296.30, 444.44, 666.67 and
1000.0 mg/L during the 48 hours observation period.

Results with reference substance (positive control):

- Results with reference substance valid? Yes, the 48 hour EC50 of the reference substance was within the acceptance range confirming the suitability of the test system. EC50 of Potassium dichromate on Daphnia magna is periodically determined. The date of the last study at the date of performing this test was 24-08-2022.
- EC50-48 h: 0.66 mg/L

Reported statistics and error estimates:

No immobility was observed in all tested concentrations during main study and data is not appropriate for EC50 calculation, hence statistical analysis was not performed.

Table 1. Summary of clinical signs and immobilisation during range finding study  

Group	Test Conc. (mg/L)	Replicate	No. of Daphnids per Replicate at Start 0 hour	Signs of toxicity and Immobility of Daphnids Observed at				Summary of Immobility at Different Time Points of Post Exposure Period
				24 hous		48 hours		Immobility (No.) of Daphnids		Cumulative No.		Percent of Immobility
				Toxic signs	I	Toxic signs	I	24 hours	48 hours	24 hours	48 hours	24 hours	48 hours
G1	0.0	1	5	N (5)	0	N (5)	0	0	0	0	0	0	0
		2	5	N (5)	0	N (5)	0	0	0	0	0	0	0
G2	0.01	1	5	N (5)	0	N (5)	0	0	0	0	0	0	0
		2	5	N (5)	0	N (5)	0	0	0	0	0	0	0
G3	0.1	1	5	N (5)	0	N (5)	0	0	0	0	0	0	0
		2	5	N (5)	0	N (5)	0	0	0	0	0	0	0
G4	1.0	1	5	N (5)	0	N (5)	0	0	0	0	0	0	0
		2	5	N (5)	0	N (5)	0	0	0	0	0	0	0
G5	10.0	1	5	N (5)	0	N (5)	0	0	0	0	0	0	0
		2	5	N (5)	0	N (5)	0	0	0	0	0	0	0
G6	50.0	1	5	N (5)	0	N (5)	0	0	0	0	0	0	0
		2	5	N (5)	0	N (5)	0	0	0	0	0	0	0
G7	100.0	1	5	N (5)	0	N (5)	0	0	0	0	0	0	0
		2	5	N (5)	0	N (5)	0	0	0	0	0	0	0

-: Not applicable; I: Immobility; N: Normal; Alphabet outside and values inside the parentheses represent the clinical symptom code and number of Daphnids exhibiting that particular symptom, respectively.

Note: Daphnids were maintained under dark condition except during clinical signs observation and renewal period. 

Table 2. Summary of clinical signs and immobility during main study 

Group	Test Conc. (mg/L)	Replicate	No. of Daphnids per Replicate at Start 0 hour	Signs of toxicity and Immobility of Daphnids Observed at				Summary of Immobility at Different Time Points of Post Exposure Period
				24 hous		48 hours		Immobility (No.) of Daphnids		Cumulative No.		Percent of Immobility
				Toxic signs	I	Toxic signs	I	24 hours	48 hours	24 hours	48 hours	24 hours	48 hours
G1	0.0	1	5	N (5)	0	N (5)	0	0
		2	5	N (5)	0	N (5)	0
		3	5	N (5)	0	N (5)	0
		4	5	N (5)	0	N (5)	0
G2	87.79	1	5	N (5)	0	N (5)	0	0
		2	5	N (5)	0	N (5)	0
		3	5	N (5)	0	N (5)	0
		4	5	N (5)	0	N (5)	0
G3	131.69	1	5	N (5)	0	N (5)	0	0
		2	5	N (5)	0	N (5)	0
		3	5	N (5)	0	N (5)	0
		4	5	N (5)	0	N (5)	0
G4	197.53	1	5	N (5)	0	N (5)	0	0
		2	5	N (5)	0	N (5)	0
		3	5	N (5)	0	N (5)	0
		4	5	N (5)	0	N (5)	0

Table 3. summary of clinical signs and mortality during main study 

Group	Test Conc. (mg/L)	Replicate	No. of Daphnids per Replicate at Start 0 hour	Signs of toxicity and Immobility of Daphnids Observed at				Summary of Immobility at Different Time Points of Post Exposure Period
				24 hous		48 hours		Immobility (No.) of Daphnids		Cumulative No.		Percent of Immobility
				Toxic signs	I	Toxic signs	I	24 hours	48 hours	24 hours	48 hours	24 hours	48 hours
G5	296.30	1	5	N (5)	0	N (5)	0	0
		2	5	N (5)	0	N (5)	0
		3	5	N (5)	0	N (5)	0
		4	5	N (5)	0	N (5)	0
G6	444.44	1	5	N (5)	0	N (5)	0	0
		2	5	N (5)	0	N (5)	0
		3	5	N (5)	0	N (5)	0
		4	5	N (5)	0	N (5)	0
G7	666.67	1	5	N (5)	0	N (5)	0	0
		2	5	N (5)	0	N (5)	0
		3	5	N (5)	0	N (5)	0
		4	5	N (5)	0	N (5)	0
G8	1000.0	1	5	N (5)	0	N (5)	0	0
		2	5	N (5)	0	N (5)	0
		3	5	N (5)	0	N (5)	0
		4	5	N (5)	0	N (5)	C

Tabla 4. Physico-chemical parameters of test medium during main study  

Group	Test Conc. (mg/L)	Replicate	Dissolved Oxygen  (mg/L)		Temperature (°C)		pH
			0 hour	48 hour	0 hour	48 hour	0 hour	48 hour
			Fresh	Spent	Fresh	Spent	Fresh	Spent
G1	0.0	1	8.06	8.00	20.6	20.4	7.38	7.31
		2	8.09	8.03	20.1	20.0	7.33	7.28
		3	8.09	8.01	20.2	20.3	7.31	7.24
		4	8.02	7.95	20.1	20.2	7.35	7.23
G2	87.79	1	8.11	8.03	20.8	20.2	7.41	7.22
		2	8.03	8.00	20.7	20.4	7.39	7.30
		3	8.06	8.02	20.02	20.02	7.46	7.41
		4	8.10	8.05	20.4	20.4	7.44	7.39
G3	131.69	1	7.96	7.90	20.4	20.1	7.47	7.45
		2	7.99	7.91	20.4	20.1	7.49	7.43
		3	7.93	7.85	20.9	20.1	7.42	7.18
		4	7.97	7.90	20.6	20.2	7.47	7.22
G4	197.53	1	7.98	7.93	20.9	20.4	7.49	7.40
		2	7.93	7.90	20.9	20.3	7.56	7.51
		3	7.94	7.91	20.3	20.4	7.57	7.50
		4	7.90	7.84	20.3	20.4	7.55	7.50
G5	296.30	1	7.99	7.95	20.3	20.2	7.57	7.51
		2	7.98	7.91	20.7	20.2	7.58	7.51
		3	7.93	7.83	20.7	20.1	7.61	7.60
		4	7.96	7.91	20.1	20.3	7.54	7.53
G6	444.44	1	7.92	7.84	20.7	20.4	7.66	7.64
		2	7.95	7.90	20.8	20.4	7.60	7.58
		3	7.93	7.87	20.7	20.5	7.58	7.51
		4	7.97	7.90	20.2	20.5	7.54	7.50
G7	666.67	1	7.96	7.91	20.6	20.5	7.59	7.63
		2	7.98	7.93	20.7	20.5	7.54	7.50
		3	7.98	7.93	20.6	20.2	7.68	7.63
		4	7.89	7.84	20.1	20.4	7.66	7.61
G8	1000.00	1	7.93	7.90	20.8	20.3	7.64	7.60
		2	7.94	7.91	20.6	20.4	7.69	7.56
		3	7.97	7.90	20.3	20.3	7.66	7.59
		4	7.98	7.94	20.8	20.2	7.65	7.60
Minimum			7.83		20.2		7.18
Maximum			8.11		20.9		7.69

 

Validity criteria fulfilled:

yes

Remarks:

(Immobilisation in control < 10% (no immobilisation observed); dissolved oxygen concentration > 3 mg O2/L)

Conclusions:

In a short-term toxicity test to Daphnia magna, the 48h-EC50 of the test substance was found to be >1000 mg/L.

Executive summary:

An acute aquatic toxicity study with Daphnia magna was conducted on test item according to OECD guideline 202, following GLP. A range finding study was conducted for 48 h with nominal loading rates of 0.01, 0.1, 1.0, 10.0, 50.0 and 100.0 mg/L  along with a control group. No clinical signs of toxicity or immobilization was observed in control group and at the tested concentrations. No clinical signs of toxicity or immobilization was observed in control group and at the tested concentrations.Based on results of the dose range finding study, the main study was conducted at the test concentrations of 87.79, 131.69, 197.53, 296.30, 444.44, 666.67 and 1000.0 mg/L along with the control group. The test was conducted in static conditions with Eight groups (1 control and 7 treatment groups) consisting of 4 replicates in each group, consisting of
5 Daphnids per replicates were used during main study.

Description of key information

Key study. Test method according to OECD 202, GLP study. The 48h-EL50 of the test substance to Daphnia magna was found to be >1000 mg/L

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

EC50

Effect concentration:

> 1 000 mg/L