Diphenyl sulphone

Long-term toxicity to fish

Link to relevant study record(s)

Reference

Endpoint:

fish early-life stage toxicity

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2021-2022

Reliability:

1 (reliable without restriction)

Qualifier:

according to guideline

Guideline:

OECD Guideline 210 (Fish, Early-Life Stage Toxicity Test)

GLP compliance:

yes

Specific details on test material used for the study:

Test concentrations were not corrected for the purity of the test substance.

Identification: Diphenyl sulphone
Batch (Lot) Number: 202011220005
Expiry date: 22 November 2022 (retest date)
Physical Description: White crystalline
Purity/Composition: 99.99%
Storage Conditions: At room temperature

Analytical monitoring:

yes

Details on sampling:

Samples (1.4 ml) for analysis were taken from all test concentrations and the control. One day before the start of exposure to check the functioning of the system. At the start and at weekly intervals (i.e. on day 7, 14, 21, and 28) of exposure.

Vehicle:

yes

Details on test solutions:

The batch of Diphenyl sulphone tested was a white crystalline powder with a purity of 99.99%. No correction was made for the purity/composition of the test item.
The standard test procedures required generation of test solutions, which should contain completely dissolved test item concentrations or stable and homogeneous mixtures or dispersions. The testing of concentrations that disturb the test system was prevented

Test organisms (species):

Pimephales promelas

Details on test organisms:

Fathead minnow (Pimephales promelas, Teleostei, Cyprinidae) Rafinesque, 1820

Test type:

flow-through

Water media type:

freshwater

Total exposure duration:

32 d

Remarks on exposure duration:

32 days post-fertilisation

Hardness:

The following salts (analytical grade) were added to tap water purified by Reverse Osmosis (RO-water, GEON Waterbehandeling, Berkel-Enschot, The Netherlands):
CaCl2.2H2O 211.5 mg/L
MgSO4.7H2O 88.8 mg/L
NaHCO3 46.7 mg/L
KCl 4.2 mg/L
The hardness of test medium expressed as CaCO3: 180 mg/L.

Test temperature:

The average temperature measured at weekly intervals in the controls and the treatment groups was within the range described in the study plan: 25 ± 1.5°C. The average temperature continuously measured in one of the replicates of the control was generally within the range described in the study plan: 25 ± 1.5°C.
temperature range 23.8-25.1 °C

pH:

The pH was within the acceptance range (6.0-8.5).

Dissolved oxygen:

Oxygen concentrations were > 60% (i.e. >5.0 mg/L) of oxygen saturation at 25°C

Salinity:

Total hardness was >140 mg/L,

Conductivity:

<10µs/cm

Nominal and measured concentrations:

see attachment.

Details on test conditions:

Summary of Experimental Conditions
Condition Range
pH 7.1 – 7.9
Temperature measured in test vessels (°C) 23.8 – 25.1
Temperature measured continuously in control vessel (°C) 24.1 – 25.1
Dissolved oxygen concentration (mg O2/L) 4.5 – 9.0
Hardness (mg CaCO3/L) 196 – 232
Total Dissolved Organic Carbon content (mg TOC/L) Light intensity (Lux) 594 - 624
LOQ: Limit of quantification (1 mg/L)

Key result

Duration:

32 d

Dose descriptor:

NOEC

Effect conc.:

1 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

length

Remarks on result:

other: for details on measurements of the test samples in the final test see table attached

Details on results:

The results of the range-finding test are:
No mortality or other adverse effects were observed at the three lowest test concentrations and the control during the eight-day test period. At the highest concentration, three larvae died and several larvae showed multiple malformations and affected swimming behaviour. Larval development and time of hatching in all treatments were comparable to the control.
Samples taken from the control and solutions containing 0.10 and 100% of the SS were analysed. The measured concentrations in the freshly prepared saturated solutions ranged between 31 and 33 mg/L at the start of the three renewal periods. Both concentrations remained stable throughout the according renewal intervals, i.e. were between 95 and 106% relative to the initial values in the 24-hour, 48-hour and 72-hour old solutions. See also Table 3 in the Analytical Report.
All test conditions were maintained within the limits prescribed by the study plan.
Based on the results of this preliminary test, it was decided to test a range of nominal concentrations between 0.46 and 10 mg/L in the final study.

In conclusion, the present study assessed the possible lethal and sub-lethal effects of Diphenyl sulphone during the embryonic and early larval development of the fathead minnow. The results led to the following conclusions for Diphenyl sulphone:
• Diphenyl sulphone did not affect the hatching success (embryonic survival) at concentrations up to and including 10 mg/L (NOEC). Hence the LOEC was >10 mg/L.
• Diphenyl sulphone significantly affected survival of larvae at the nominal concentration of 10 mg/L (LOEC). Hence, the NOEC was 4.6 mg/L.
• Diphenyl sulphone had a significant effect on the growth of the exposed larvae. Body weight was significantly affected at nominal concentrations of 4.6 mg/L and higher (LOEC), while body length was affected at nominal concentrations of 2.2 mg/L and higher (LOEC) at the end of the exposure. The NOEC was 2.2 and 1.0 mg/L for weight and length, respectively.
The overall NOEC of Diphenyl sulphone for the early life stages of fish was 1.0 mg/L and the overall LOEC was 2.2 mg/L.

Validity of the study.

The dissolved oxygen concentration was maintained above 60% of the air saturation value throughout the test, except for two tanks on day 28, see Deviations in Appendix 7.
2. The water temperature did not differ by more than ± 1.5°C between test chambers between successive days at any time during the test, and was within the temperature ranges specified for the test species;
3. Exposure concentrations during the test period were analytically monitored;
4. Overall survival of fertilised eggs in the controls was >70% until hatching was complete (i.e. 99 and 100%, for the blank control and the solvent control , respectively). The overall survival of hatched larvae was >75% in the controls during the remaining test period (i.e. 94 and 98%, for the blank control and the solvent control, respectively).

Results with reference substance (positive control):

Overall survival of fertilised eggs in the controls was >70% until hatching was complete (i.e. 99 and 100%, for the blank control and the solvent control , respectively). The overall survival of hatched larvae was >75% in the controls during the remaining test period (i.e. 94 and 98%, for the blank control and the solvent control, respectively).

Validity criteria fulfilled:

yes

Conclusions:

he overall NOEC of Diphenyl sulphone for the early life stages of fish was 1.0 mg/L

Executive summary:

In conclusion, the present study assessed the possible lethal and sub-lethal effects of Diphenyl sulphone during the embryonic and early larval development of the fathead minnow. The results led to the following conclusions for Diphenyl sulphone:

• Diphenyl sulphone did not affect the hatching success (embryonic survival) at concentrations up to and including 10 mg/L (NOEC). Hence the LOEC was >10mg/L.


• Diphenyl sulphone significantly affected survival of larvae at the nominal concentration of 10 mg/L (LOEC). Hence, the NOEC was 4.6 mg/L.


• Diphenyl sulphone had a significant effect on the growth of the exposed larvae. Body weight was significantly affected at nominal concentrations of 4.6 mg/L and higher (LOEC), while body length was affected at nominal concentrations of 2.2 mg/L and higher (LOEC) at the end of the exposure. The NOEC was 2.2 and 1.0 mg/L for weight and length, respectively.

The overall NOEC of Diphenyl sulphone for the early life stages of fish was 1.0 mg/L and the overall LOEC was 2.2 mg/L.

Description of key information

The chronic toxicity of Diphenylsulfone was assessed in a Flow- Through  28 days post hatch test according to OECD 210,  in order to define  lethal and sub-lethal effects of Diphenyl sulphone, using Fathead minnow fish as test species.
The test substance concentration were analytical verified. All validity criteria were fulfilled. After 28 days of exposure an overall  NOEC (length) of 1.0 mg/L was determined.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Dose descriptor:

NOEC

Effect concentration:

1 mg/L

Additional information

The chronic aquatic toxicity in fish (ELS)was determined as 1 mg/L  in the  OECD 210 study with  Diphenyl sulfone.