Diphenyl sulphone

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2021

Reliability:

1 (reliable without restriction)

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

GLP compliance:

yes

Specific details on test material used for the study:

Diphenyl sulphone
Lot nr 202011220005
Diphenyl sulphone content: 99.99 %

Analytical monitoring:

yes

Details on sampling:

Samples for possible analysis were taken from all concentrations and the control.
Frequency at t=0 h and t=96 h
Volume 1.4 mL
Storage Samples were stored in a freezer (set to maintain -20°C) until analysis at the analytical laboratory of the Test Facility.
Additionally, reserve samples of 1.4 mL were taken from all test solutions for possible analysis. If not already used, these samples were stored in a freezer (set to maintain -20°C) for a maximum of three months after delivery of the draft report, pending on the decision of the sponsor for additional analysis.

Vehicle:

no

Details on test solutions:

The batch of Diphenyl sulphone tested was a white crystalline powder with a purity of 99.99% and was not completely soluble in test medium at the loading rate initially prepared. No correction was made for the purity/composition of the test item.
Preparation of test solutions started with a loading rate of 100 mg/L applying a fifteen-minute period of ultrasonic waves followed by a three-day period of magnetic stirring to ensure maximum dissolution of the test item in medium. Thereafter, the aqueous Saturated Solution (SS) was collected by filtration through a 0.45 µm membrane filter (RC55, Whatman) and used as the highest test concentration. Lower test concentrations were prepared by subsequent dilutions of the SS in test medium. All test solutions were clear and colourless at the end of the preparation procedure.

Test organisms (species):

Cyprinus carpio

Details on test organisms:

Species Carp (Cyprinus carpio, Teleostei Cyprinidae).
Source ‘De Haar Vissen’, Zodiac proefacc. Wageningen University & Research, The Netherlands.
In case of a different supplier, details of the source will be included in the report.
Mean length Range-finding test: 2.4 ± 0.2 cm
Limit test: 2.6 ± 0.3 cm
Mean weight1 Range-finding test: 0.17 ± 0.07 g
Limit test: 0.23 ± 0.09 g
Characteristics F1 from a single parent-pair bred in UV-treated water.

Reason for selection This system has been selected as an internationally accepted species. Healthy fish supplied with a health certificate.

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

96 h

Hardness:

180 mg/L expressed as CaCo3

Test temperature:

21-22°C

pH:

between 7.5 -7.8

Dissolved oxygen:

Between 6.5- 8.8 mg/L

Conductivity:

<=10 µS/cm

Details on test conditions:

TEST SYSTEM
- Test vessel: 6.5 Liter
- Type (delete if not applicable): closed
- Material, size, headspace, fill volume: glass, 1.5 liter headspace
- Volume of solution: 5 Liter
- Aeration: no Aeration
- Type of flow-through (e.g. peristaltic or proportional diluter):
- Renewal rate of test solution (frequency/flow rate):no renewals, static
- No. of organisms per vessel: 7/ test group
- No. of vessels per concentration (replicates):2
- No. of vessels per control (replicates):2
- No. of vessels per vehicle control (replicates):no vehicle used
- Biomass loading rate:

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water:tap water purified (≤10 μS/cm. ) by Reverse Osmosis (RO-water, GEON Waterbehandeling, Berkel-Enschot, The Netherlands):
- Total organic carbon:
- Particulate matter:
- Metals:
- Pesticides:
- Chlorine:
- Alkalinity:
- Ca/mg ratio:
- Culture medium different from test medium:
- Intervals of water quality measurement:pH, O2 and temperature were daily measured in test and control vessels.

OTHER TEST CONDITIONS
- Adjustment of pH:no
- Photoperiod:16 h
- Light intensity:540-1000 lux

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :

TEST CONCENTRATIONS
- Spacing factor for test concentrations: main test was a limit test at 29 mg/L
- Justification for using less concentrations than requested by guideline:
- Range finding study
- Test concentrations: 0.1,1,10 and 100 % of a saturated DPS solution was used 10% of SS was measured as 2.9 mg/L and 100 % of SS was measured as 27 mg/L
- Results used to determine the conditions for the definitive study:no mortality

Reference substance (positive control):

not required

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 29 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Remarks on result:

other: the 96h-LC50 for carp exposzed to DPS is beyond the tested 29 mg/L ( limit test). 29 mg/L being considered the maximum concentration soluble in test medium at a loading rate of 100 mg/L

Details on results:

- Other abnormalities: no
- Observations on body length and weight:
- Other biological observations:no
- Mortality of control: no
- Other adverse effects control:no
- Hatching rate control and treatment groups (embryo):
- Abnormal responses:
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values:
- Effect concentrations exceeding solubility of substance in test medium:

Sublethal observations / clinical signs:

Sub-Lethal Effects Observed in the Limit Test

Diphenyl sulphone Geometric mean conc. (mg/L)	Time of recording (hours)	Specification of effects	Relative number
29	3	Discoloured Swimming at bottom of vessel Hyperactive reaction after external stimulation	6/7
	24	Discoloured Swimming at bottom of vessel Hypoactive swimming	7/7
	48 72 96	Discoloured Swimming at bottom of vessel	7/7

Validity criteria fulfilled:

yes

Remarks:

1. No mortality was observed in the control throughout the test. 2. The dissolved oxygen concentration has been at least 60% of the air saturation value throughout the test (>5 mg/L at 22°C). 3. Test concentrations have been analytically measured.

Conclusions:

In conclusion, the 96h-LC50 for carp (Cyprinus carpio) exposed to Diphenyl sulphone was beyond the range of concentrations tested, i.e. exceeded a geometric mean concentration of 29 mg/L being considered the maximum concentration soluble in test medium at a loading rate of 100 mg/L.

Executive summary:

The objective of the study was to evaluate Diphenyl sulphone for its ability to generate acute toxic effects in Carp (Cyprinus carpio) during an exposure period of 96 hours .A range-finding test was performed to provide information about the range of concentrations to be used in the final test. In the DRF study no mortality was observed at any of the test concentrations throughout the test                                                                                                                           Based on these results, samples taken from solutions containing 10 and 100% of the SS prepared at a loading rate of 100 mg/L were analysed. The measured concentrations at the start of the test were 2.9 and 27 mg/L, respectively. During the exposure period, the concentrations remained stable, i.e. were at 92-100% relative to initial at the end of the test ).

                                                 Dose range-finding :test samples

Time of Sampling (hours)	Date of sampling	Date of analysis	Percentage of  SS	Analysed Concentration mg/L	Relative to initial (%)
0	31 may 2021	9 Jun 2021	10 100	2.90 27.3
96	04 Jun 2021	9 Jun 2021	10 100	2.66 27.3	92 100

 

           
Incidence of Mortality and Total Mortality During the Range-Finding Test

Diphenyl sulphone %SS prep. at a loading rate of 100 mg/L	Initial number of fish	Cumulative mortality					Total Mortality (%)
		3h	24h	48h	72h	96h
0.10	3	0	0	0	0	0	0
1.0	3	0	0	0	0	0	0
10	3	0	0	0	0	0	0
100	3	0	0	0	0	0	0

 

It was decided to perform the  definitive test at the  Limit concentration: solution containing 100% of the SS prepared at a loading rate of 100 mg/L.

Samples taken from the limit concentration and the control were analysed. The measured concentration at the start of the test was 29 mg/L. The concentration remained stable during the exposure period, i.e. was at 99% relative to initial at the end of the test.

Low levels of test item were detected in the samples taken from the control at the start and end of the test. The levels were below the limit of detection (0.2 µg/L) and were concluded to not have impacted the study interpretation as the control fish showed no mortality or other signs of distress. Based on these results, the geometric mean concentration of the limit concentration was calculated to be 29 mg/L and used to express effect parameters.

 

Limit test :test samples

 

Time of Sampling (hours)	Date of sampling	Date of analysis	Percentage of  SS (%)	Analysed Concentration mg/L	Relative to initial (%)
0	31 may 2021	10 Jun 2021	10 100	<LOD 28.8
96	04 Jun 2021	10 Jun 2021	10 100	<LOD 28.5	n.a. 99

 

 

A limit test  at  29 mg/L was performed based on the results of a range-finding test. The study met the validity criteria prescribed by the study plan and was considered valid. Test conditions and results of the limit test are presented in the table below:

           

 

 

Incidence of Mortality and Total Mortality in the Limit Test

Diphenyl sulphone Geometric mean conc. (mg/L)	Initial Number of fish	Cumulative mortality					Total Mortality (%)
		3h	24h	48h	72h	96h
Control	7	0	0	0	0	0	0
29	7	0	0	0	0	0	0

 

In conclusion, the 96h-LC₅₀ for carp (Cyprinus carpio) exposed to Diphenyl sulphone was beyond the range of concentrations tested, i.e. exceeded a geometric mean concentration of 29 mg/L being considered the maximum concentration soluble in test medium at a loading rate of 100 mg/L.

 

Description of key information

In conclusion, the 96h-LC₅₀ for carp (Cyprinus carpio) exposed to Diphenyl sulphone was beyond the range of concentrations tested, i.e. exceeded a geometric mean concentration of 29 mg/L being considered the maximum concentration soluble in test medium at a loading rate of 100 mg/L.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Dose descriptor:

LC50

Effect concentration:

> 29 mg/L