Diphenyl[4-(phenylsulfanyl)phenyl] sulfonium hexafluoroantimonate(1-)

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 -20 May 2019

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

This study was conducted in accordance with International Guidelines (OECD 202) and in accordance with OECD Principles of Good Laboratory Practice as incorporated into the United Kingdom Statutory Instrument for GLP. All validity criteria were met.

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

2004

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Version / remarks:

2008

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 0.1, 0.32, 1.0, 3.2 and 10 % v/v saturated solution
- Sampling method: Samples placed in amber bottles were taken from the control and each test group from the bulk test preparation at 0 and 24 hours and from the pooled (remaining) replicates at 24 and 48 hours for analysis. Duplicate sets of samples were taken at 0, 24 (fresh and used) and 48 hours and stored frozen for further analysis if necessary.
- Sample storage conditions before analysis: None, samples analysed immediately.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: 1100 mg test item added to 11 L of Elendt M7 medium with stirring at 1500 rpm for 24 hours. After 24 hours, stirring was stopped and undissooved test item was removed by filtration through a 0.2 μm Sartorius Sartopore filter; the first two liters passed through the filter were discarded. This gave a 100 % v/v saturated solution. A series of dilutions were made from this saturated solution to give the required test concentrations (0.1, 0.32, 1.0, 3.2 and 10 % v/v saturated solutions).
- Controls: untreated control only(medium only)

-Positive control: A positive control (Envigo study number KC41PP) used potassium dichromate as the reference item at concentrations of 0.32, 0.56, 1.0, 1.8 and 3.2 mg/L. The positive control was conducted between 25 - 27 September 2018. Exposure conditions for the positive control were similar to those in the definitive test with the exception of the light intensity (mean of 1037 lux, compared to the definitive test being conducted under non-actinic light)

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna
- Source: in-house laboratory cultures
- Feeding during test: none
- Food type: N/A
- Amount: N/A
- Frequency: N/A

ACCLIMATION
- Acclimation period: not required, test water and environmental parameters were the same as husbandry water and conditions.
- Acclimation conditions (same as test or not): N/A
- Type and amount of food: N/A
- Feeding frequency: N/A
- Health during acclimation (any mortality observed): N/A


METHOD FOR PREPARATION AND COLLECTION OF EARLY INSTARS OR OTHER LIFE STAGES: Adult daphnids were kept in 150 mL beakers with 100 mL of Elendt M7 medium and were fed daily with an algal suspension (P.subcapitata) and GM300 fish food suspension. Gravid adults were isolated the day before test initiation, such that any young daphnids produced overnight were less than 24 hours old. The young were removed from the cultures and were used for testing.

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

not reported

Test temperature:

20-21 °C

pH:

7.9-8.2

Dissolved oxygen:

8.8-9.4 mg O2/L

Salinity:

N/A

Conductivity:

not reported

Nominal and measured concentrations:

Nominal (% v/v saturated solutions): 0.1, 0.32, 1.0, 3.2, 10; Geometric Mean Measured Concentrations (mg/L): 0.0451, 0.137, 0.470, 1.61, 5.75

Details on test conditions:

TEST SYSTEM
- Test vessel: 120 mL glass vessels
- Type (delete if not applicable): open but covered to reduce evaporation
- Material, size, headspace, fill volume: glass, containing 100 mL test solution
- Aeration: none
- Type of flow-through (e.g. peristaltic or proportional diluter): none
- Renewal rate of test solution (frequency/flow rate): test solutions renewed at 24 h. Concentrations at which 100% immobilisation had occurred were not renewed.
- 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 vehicle control
- Biomass loading rate: not reported

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Elendt M7 Medium; H3BO3: 0.715 mg/L, MnCl2.4H2O: 0.090 mg/L, LiCl: 0.077 mg/L, RbCl: 0.018 mg/L, SrCl2.6H2O: 0.038 mg/L, NaBr: 0.004 mg/L, Na2MoO4.2H2O: 0.016 mg/L, CuCl2.2H2O: 0.004 mg/L, ZnCl2: 0.013 mg/L, CoCl2.6H2O: 0.010 mg/L, KI: 0.0033 mg/L, Na2SeO3: 0.0022 mg/L, NH4VO3: 0.00058 mg/L, Na2EDTA.2H2O: 0.625 mg/L, FeSO4.7H2O: 0.249 mg/L, CaCl2.2H2O: 293.8 mg/L, NaHCO3: 64.8 mg/L, MgSO4.7H2O: 123.3 mg/L, Na2SiO3.9H2O: 10 mg/L, KCl: 5.8 mg/L, NaNO3: 0.274 mg/L, K2HPO4: 0.184 mg/L, KH2PO4: 0.143 mg/L, Thiamine hydrochloride: 0.075 mg/L, Cyanocobalamine: 0.0010 mg/L, D(+) biotin: 0.00075 mg/L. The pH of the prepared media was 7.9 ± 0.3 and stored at approximately 21 ºC.

- Total organic carbon: not reported
- Particulate matter: not reported
- Metals: not reported
- Pesticides: not reported
- Chlorine: not reported
- Alkalinity: not reported
- Ca/mg ratio: not reported
- Conductivity: not reported
- Salinity: not reported
- Culture medium different from test medium: no
- Intervals of water quality measurement: daily, at 24 hours fresh and old media was measured.

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: none, test conducted in the dark
- Light intensity: test conducted in the dark

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : immobilization at 24, 48 h.

VEHICLE CONTROL PERFORMED: no

RANGE-FINDING STUDY
- Test concentrations: 0.1, 1, 10, 100 % v/v saturated solutions
- Results used to determine the conditions for the definitive study: yes

Reference substance (positive control):

yes

Remarks:

Potassium dichromate, 24h EC50 of 1.1 mg/L, 48 h EC50 of 0.8 mg/L

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

0.25 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other:

Remarks:

95% CI: 0.14 - 0.45 mg/L

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

0.25 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other:

Remarks:

95% ci: 0.14 - 0.45 mg/L

Details on results:

- Behavioural abnormalities: N/A
- Observations on body length and weight: N/A
- Other biological observations: N/A
- Mortality of control: None
- Other adverse effects control: None
- Abnormal responses: None
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: None
- Effect concentrations exceeding solubility of substance in test medium: no

Results with reference substance (positive control):

- Results with reference substance valid? yes
- Relevant effect levels: yes
- Limit test: no
- Dose-response test: yes; 0.32, 0.56, 1.0, 1.8 and 3.2 mg/L potassium dichromate tested
- ECx: 24 h: 1.1 mg/L (95% CI: 0.95-1.3 mg/L), 48h: 0.80 mg/L (95% CI: 0.12 - 1.5 mg/L)
- Other: Study number KC41PP, test conducted between 25-27 September 2018

Reported statistics and error estimates:

The EC50 values and associated confidence limits at 24 and 48 hours were calculated by Weibull analysis using Linear Maximum-Likelihood regression. The Lowest Observed Effect Concentration (LOEC) and the No Observed Effect Concentration (NOEC) at 24 and 48 hours were calculated using the Step-down Cochran-Armitage Test Procedure. All results were calculated using ToxRat Professional.

Table 1 Immoblization Data in the Definitive Test

Geometric Mean Measured Concentration (mg/L)	24 Hours						48 Hours
	Cumulative Immobilized Daphnia
	Rep 1	Rep 2	Rep 3	Rep 4	Total	%	Rep 1	Rep 2	Rep 3	Rep 4	Total	%
Control	0	0	0	0	0	0	0	0	0	0	0	0
0.0451	0	0	0	0	0	0	0	0	0	0	0	0
0.137	0	1	0	0	1	5	0	1	0	0	1	5
0.470	5	5	5	5	20	100	-	-	-	-	-	-
1.61	5	5	5	5	20	100	-	-	-	-	-	-
5.75	5	5	5	5	20	100	-	-	-	-	-	-

-: no daphnids present. The daphnids were removed after the 24 hour observation as they were all observed to be immobilised

Table 2 Water Quality Measurements

Geometric Mean Measured Concentration (mg/L)	Replicate	0 hours (Fresh Media)			24 hours (Old Media)			24 hours (Fresh Media)			48 hours (Old Media)
		pH	mg O2/L	°C	pH	mg O2/L	°C	pH	mg O2/L	°C	pH	mg O2/L	°C
Control	1	8.0	9.4	20	7.9	9.2	20	8.1	9.2	21	8.2	8.8	20
0.0451	1	8.0	9.2	20	8.0	9.2	20	7.9	9.2	21	8.1	9.3	20
0.137	1	8.0	9.2	20	7.9	9.2	20	7.9	9.2	21	8.1	9.1	20
0.470	1	8.0	9.2	20	7.9	9.1	20	-	-	-	-	-	-
1.61	1	8.0	9.2	20	7.9	9.4	20	-	-	-	-	-	-
5.75	1	8.0	9.2	20	7.9	9.2	20	-	-	-	-	-	-

Table 3 Analytical Results

Timepoint (Hours)	Nominal Concentration of Test Item in Sample (% v/v Saturated Solution)	Sample Preparation Factor	Determined Concentration of Test Item in Test Sample (mg/L)
0 (fresh)	Control 0.10 0.32 1.0 3.2 10	4 20 40 80 400 800	<LOQ 0.0480 0.151 0.488 1.67 6.53
Procedural Recovery Procedural Recovery	0.108 0.108	20 20	0.105 (97%) 0.104 (96%)
24 (old)	Control 0.10 0.32 1.0 3.2 10	4 20 40 80 400 800	0.0137 /<LOQ* 0.0521 0.145 0.453 1.56 5.07
Procedural Recovery Procedural Recovery	0.103 0.103	20 20	0.101 (99% 0.0796 (77%)
24 (fresh)	Control 0.10 0.32	4 20 40	<LOQ 0.0426 0.138
48 (old)	Control 0.10 0.32	4 20 40	<LOQ 0.0380 0.115
Procedural Recovery Procedural Recovery	0.0976 0.0976	20 20	0.103 (106%) 0.0988 (101%)

* duplicate sample, frozen prior to analysis

Validity criteria fulfilled:

yes

Conclusions:

The 48 hour EC50 of CPI-110A to D. magna was estimated to be 0.25 mg/L (95% CL: 0.14-0.45 mg/L)

Executive summary:

A study was performed according to OECD 202 (2004) to assess the acute toxicity of the test item to Daphnia magna. Due to light sensitive nature of the test item all media preparations were conducted under non-actinic light throughout the study. Following a range-finding test, 20 daphnids (4 replicates of 5 animals) were exposed to aqueous solutions of the test item at nominal concentrations of 0.10, 0.32, 1.0, 3.2 and 10% v/v saturated solution for 48 hours under semi-static test conditions, in the dark. Chemical analysis showed measured test concentrations to range from 0.0426 to 6.53 mg/L. The geometric mean measured test concentrations were determined to be 0.0451, 0.137, 0.470, 1.61 and 5.75 mg/L. Exposure of Daphnia magna to the test item gave the following results based on geometric mean measured test concentrations: 48-h EC₅₀– 0.25 mg/L. All validity criteria were met.

Description of key information

48h EC₅₀ - 0.25 mg/L; OECD 202; Hull K (2019)

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

0.25 mg/L

Additional information

A study was performed according to OECD 202 (2004) to assess the acute toxicity of the test item toDaphnia magna. Due to light sensitive nature of the test item all media preparations were conducted under non-actinic light throughout the study. Following a range-finding test, 20 daphnids (4 replicates of 5 animals) were exposed to aqueous solutions of the test item at nominal concentrations of 0.10, 0.32, 1.0, 3.2 and 10% v/v saturated solution for 48 hours under semi-static test conditions, in the dark. Chemical analysis showed measured test concentrations to range from 0.0426 to 6.53 mg/L. The geometric mean measured test concentrations were determined to be 0.0451, 0.137, 0.470, 1.61 and 5.75 mg/L. Exposure ofDaphnia magnato the test item gave the following results based on geometric mean measured test concentrations: 48-h EC₅₀– 0.25 mg/L. All validity criteria were met.