Dipotassium methanedisulphonate

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:

04 September 2017 - 16 March 2018

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: 0 (control, G1) and 100 mg/L (G2)
- Sampling method: A volume of 2.0 mL sample solution from the group G1 and G2 were transferred into separate volumetric flask of 10 mL capacity. A volume of 0.5 mL 1:1 nitric acid solution was added to each flask and the volume of each flask was made up to the mark with reconstituted water.
- Sample storage conditions before analysis: not applicable

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: A quantity of 100.0 mg dipotassium methanedisulphonate was transferred in 10 mL volumetric flask and volume was made up to the mark with reconstituted water to obtain the nominal concentration of 10 mg/mL (stock A). Volume of 1600 µL was taken from the stock A, transferred using a micropipette and diluted to 160 mL with reconstituted water in glass beakers of 600 mL capacity to obtain the nominal test concentration of 100.0 mg dipotassium methanedisulphonate/L.
- Controls: Reconstituted water (negative) and potassium dichromate (positive)

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna
- Source: MicroBio Test Inc, Kleimoer 15, 9030 Mariakerke (Gent), Belgium
- Age of parental stock (mean and range, SD): no data
- Feeding during test: No

ACCLIMATION
- Acclimation period: 48 h
- Acclimation conditions (same as test or not): same as test: mean temperature of 19.9 ± 0.1 °C, mean dissolved oxygen level of 8.60 ± 0.07 mg/L as air saturation value, mean pH of 7.37 ± 0.05 measured daily and kept under a 16 h light and 8 h dark photoperiod during acclimatisation. The total hardness measured was 190.4 mg/L as CaCO3 and light intensity measured was 1320 Lux, on the day of acclimatisation.
- Type and amount of food: live algal cells (Pseudokirchneriella subcapitata)
- Feeding frequency: no specified
- Health during acclimation (any mortality observed): no mortalities reported.

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Post exposure observation period:

None

Hardness:

184.8 mg/L as CaCO3

Test temperature:

19.9-20.2ºC

pH:

7.62-7.87

Dissolved oxygen:

8.12-8.28 mg O2/L

Salinity:

No data

Conductivity:

No data

Nominal and measured concentrations:

Nominal concentrations: 0 (control) and 100 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: glass beaker
- Material, size, headspace, fill volume: glass, 600 mL capacity, 160 mL fill volumen
- Aeration: diluent water was aerated before starting the test so that dissolved oxygen concentration reached saturation.
- Renewal rate of test solution (frequency/flow rate): No 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): N/A
- Biomass loading rate: 5 daphnids in 160 mL of test media

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: reconstituted water (ISO test water)
- Intervals of water quality measurement: Temperature, pH, and dissolved oxygen content (using Multi portable meter) of reconstituted water were recorded at 0 and 48 h. Total hardness of reconstituted water was measured once during acclimatisation and test period using the titrimetric method (IS 3025, 1983).

OTHER TEST CONDITIONS
- Adjustment of pH: No
- Photoperiod: 16 h light and 8 h dark cycle
- Light intensity: ranged between 1310 and 1330 Lux

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : All test daphnids were observed for immobility and abnormal behaviour or appearance, at 0, 24, and 48 h of exposure. Mobility of the daphnids was assessed by gently swirling the test container for 15 seconds and observing their swimming behaviour. Daphnids unable to swim during the agitation of the test container and remaining settled on the water surface or settled at the bottom of the test vessel were recorded as immobile.

VEHICLE CONTROL PERFORMED: N/A

RANGE-FINDING STUDY
- Test concentrations: 0.0 [control], 0.01, 0.1, 1.0, 10.0 and 100.0 mg test item/L.
- Results used to determine the conditions for the definitive study: The percent immobility observed were 0, 0, 0, 0, 0 and 0 at the test concentrations of 0.0 [control], 0.01, 0.1, 1.0, 10.0 and 100.0 mg/L., respectively.

Reference substance (positive control):

yes

Remarks:

(potassium dichromate)

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

- Behavioural abnormalities: Daphnids exposed to 100 mg/L and control did not exhibit any abnormal behavioural symptoms at 24 and 48 h.
- Mortality of control: No mortality was observed over a period of 48 h in the control group

Results with reference substance (positive control):

- Results with reference substance valid? Yes
- Relevant effect levels: The percent immobilisations observed at 48 h were 0, 35, 90, 100 and 100 at the test concentrations of 0.09, 0.20, 0.44, 0.96 and 2.11 mg potassium dichromate/L, respectively.
At 48 h, lethargy was observed in G3 (0.20 mg/L) and G4 (0.44 mg/L). All the daphnids were found immobile at the test concentrations of G5 (0.96 mg/L) and G6 (2.11 mg/L). No immobility and behavioural symptoms were observed in G2 (0.09 mg/L), and G1 (control) group.
- EC50-48 h: 0.24 mg/L

Reported statistics and error estimates:

As the study was conducted as a limit test, probit analysis was not carried out.

Table 1: Immobility Data at 0, 24 and 48 h Exposure Period

Group	Test Concentration (mg/L)	N° of Replicates	N° of Daphnia/group	Immobility N° and % at
				0 h	24 h	%	48 h	%
G1	0.0 (Control)	4	20	0	0	0	0	0
G2	100.0	4	20	0	0	0	0	0

Table 2: Behavioral Symptoms (Main Study)

Group	Test  Concentration(mg/L)	Behavioral Symptoms Observed at
		0 h				24 h				48 h
		R1	R2	R3	R4	R1	R2	R3	R4	R1	R2	R3	R4
G1	0.0 (Control)	1(5)	1(5)	1(5)	1(5)	1(5)	1(5)	1(5)	1(5)	1(5)	1(5)	1(5)	1(5)
G2	100.0	1(5)	1(5)	1(5)	1(5)	1(5)	1(5)	1(5)	1(5)	1(5)	1(5)	1(5)	1(5)

Behavioral symptom: 1 = Normal

Note: Figures presented outside parentheses refer the clinical symptom and inside parentheses refer the total number of daphnia.

Table 3: Mean Values of Water Parameters of Test Solution

Groups	Test Concentration  (mg/L)	pH				Temperature (°C)				Dissolved Oxygen (mg/L)				Total Hardness (as CaCO3) mg/L water
		0 h		48 h		0 h		48 h		0 h		48 h
		Mean	SD	Mean	SD	Mean	SD	Mean	SD	Mean	SD	Mean	SD	184.8
G1	0.0 (Control)	7.62	0.106	7.73	0.111	19.9	0.50	20.2	0.08	8.28	0.118	8.16	0.097
G2	100.0	7.80	0.037	7.87	0.024	20.2	0.19	20.2	0.06	8.28	0.064	8.12	0.073

Validity criteria fulfilled:

yes

Remarks:

(mortality 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 greater than 100 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 preliminary range finding study was conducted with test concentrations of 0.0 (control), 0.01, 0.1, 1.0, 10.0 and 100.0 mg/L for a period of 48 h with 60 daphnids, divided into six groups of 10 daphnids per group. Based on no mortalities found in this preliminary study, the main test was restricted to limit study conducted with single test concentration of 100.0 mg/L. Reconstituted water (ISO test water) was used as test medium. In the previous solubility study the test item was found to be soluble in reconstituted water so no vehicle was used for the study. The main test was conducted with test concentrations of 0.0 (control) and 100.0 mg/L for a period of 48 h in static conditions in 4 replicates of 5 daphnids per replicate. The test solutions were not aerated during the exposure. A validated analytical method based on ICP-OES was used to monitor the concentration and stability of the active ingredient in the test solution at 0 and 48 h of the main study. The active ingredient concentration in the test solution was within acceptable limit (> 80% of nominal concentration). All validity criteria were fulfilled. No immobilisation and no abnormal behavioural symptoms were observed over the period of 48 h at the test concentration of 100.0 mg/L as well as in the control group. Thus, EC50 (48 h), NOEC and LOEC to Daphnia magna of the test substance were found to be greater than 100.0 mg/L.

Description of key information

Key study. Test method according to OECD 202, GLP study. The 48h-EC50 of the test substance to Daphnia magna was found to be greater than 100.0 mg/L.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

100 mg/L

Additional information

Key study. An acute aquatic toxicity study with Daphnia magna was conducted on test item according to OECD guideline 202, following GLP. A preliminary range finding study was conducted with test concentrations of 0.0 (control), 0.01, 0.1, 1.0, 10.0 and 100.0 mg/L for a period of 48 h with 60 daphnids, divided into six groups of 10 daphnids per group. Based on no mortalities found in this preliminary study, the main test was restricted to limit study conducted with single test concentration of 100.0 mg/L. Reconstituted water (ISO test water) was used as test medium. In the previous solubility study the test item was found to be soluble in reconstituted water so no vehicle was used for the study. The main test was conducted with test concentrations of 0.0 (control) and 100.0 mg/L for a period of 48 h in static conditions in 4 replicates of 5 daphnids per replicate. The test solutions were not aerated during the exposure. A validated analytical method based on ICP-OES was used to monitor the concentration and stability of the active ingredient in the test solution at 0 and 48 h of the main study. The active ingredient concentration in the test solution was within acceptable limit (> 80% of nominal concentration). All validity criteria were fulfilled. No immobilisation and no abnormal behavioural symptoms were observed over the period of 48 h at the test concentration of 100.0 mg/L as well as in the control group. Thus, EC50 (48 h), NOEC and LOEC to Daphnia magna of the test substance were found to be greater than 100.0 mg/L.