4,4'-sulphonyldiphenol

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:

25.04.2018 - 29.05.2018

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

This study is a range finding test and does not include all aspects required by the standard test guidelines. Main modifications: a)Reduced number of replicates (2) per treatment group. b) Increased number of test concentrations (8 test concentrations and control). c) Growth assessment on study day 33/34 (not 30 days after end of hatch).

Qualifier:

according to guideline

Guideline:

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

Deviations:

yes

Remarks:

Reduced number of replicates (2) per treatment group. Increased number of test concentrations (8 test concentrations and control). Growth assessment on study day 33/34 (not 30 days after end of hatch).

GLP compliance:

no

Remarks:

This study does not have a GLP status. However, the experimental conduct of this study was carried out in general in accordance with the OECD GLP Principles.

Specific details on test material used for the study:

Test substance No.: 15/0066-8
Batch: 03508136W0
Purity: 99.6 area-% (HPLC)

Analytical monitoring:

yes

Details on sampling:

Analytical concentration controls in the test vessels were conducted at start of exposure (study day 0), before insertion of fertilized eggs and then once weekly. Samples were taken alternating between the 2 replicates per test group. Samples were taken from all concentration groups and in the control group directly from the middle of the test vessel. Additional samples were collected in those cases when deviations >20% from the nominal values were obtained to confirm that the deviations were transient, and that the concentration had returned to nominal on the subsequent days.

Vehicle:

no

Test organisms (species):

Danio rerio (previous name: Brachydanio rerio)

Test type:

flow-through

Water media type:

freshwater

Limit test:

no

Total exposure duration:

34 d

Hardness:

approx. 100 mg/L CaCO3

Test temperature:

27 +/-1 °C

pH:

7.5 - 8.5

Dissolved oxygen:

The dissolved oxygen in all replicates was measured twice weekly and maintained above 60% of the maximum saturation at 27 +/- 1.5 °C

Conductivity:

approx. 250 µS/cm (at 25 °C)

Nominal and measured concentrations:

Nominal (mg/L): 0 (control), 0.0032, 0.010, 0.032, 0.100, 0.320, 1.000, 3.200, 10.000
Meaured (mean, mg/L):

Key result

Duration:

34 d

Dose descriptor:

NOEC

Effect conc.:

>= 10 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

number hatched

Remarks:

Hatch rate

Key result

Duration:

34 d

Dose descriptor:

NOEC

Effect conc.:

>= 10 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: post hatch survival

Key result

Duration:

34 d

Dose descriptor:

LOEC

Effect conc.:

> 10 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: post hatch survival

Key result

Duration:

34 d

Dose descriptor:

NOEC

Effect conc.:

>= 10 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks:

Growth as length and weight

Key result

Duration:

34 d

Dose descriptor:

LOEC

Effect conc.:

> 10 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks:

growth as length and weight

Details on results:

The following endpoints were evaluated from these observations:
• time to hatch and swim up
• hatching success
• juvenile survival
• overall survival
• growth (total length and wet weight)
• deformations or behavioral effects
Hatching success was calculated as the percentage of embryos that hatched successfully, irrespective of larval survival. Stage-specific survival was calculated from the number of embryos, larvae, or juvenile fish that survived as a percentage of the number of survivors from the preceding stage. Survival was calculated as the fraction of surviving fish on study days 33/34at test termination from the number of embryos at test initiation. Growth was measured as total length and body weight on study days 33/34.

Hatching and Survival

Survival in the control group: Control hatching ratewas 98% and post hatch survivalwas 100% from end of swim-up to day 33/34. Thus the quality criteria for control treatment survival requested in the test guideline were satisfied.

The hatch rate was not impaired in any of the concentration groups in comparison to the control group. In the control group, hatch started on day 3 and was complete on day 5. In test groups hatch started and ended simultaneously with the control group. The first observed swim-up occurred on day 5 in the control and test groups and was complete by day 6.There was no statistically significant decrease in fish survival in any test group from end of swim-up untiltermination (day 5–33/34) as assessed by Fishers exact test. Over the whole exposure period no significant mortality occurred in any test group. In conclusion, the NOEC for survival is ≥10000 µg/L (nominal concentration) and the LOEC is >10000 µg/L (nominal concentration).

Growth as length and weight

Using the Williams test and/or Dunnett´s testin comparison to the control group the mean wet weights of the surviving fish in all test groups at the end of the exposure period were not statistically significantly decreased.The total body lengths of the surviving fish in all test groups at the end of the exposure period were not statistically significantly decreased.

In conclusion, for growth impairment the NOEC is ≥10 mg/L (nominal concentration) and the LOEC is >10 mg/L (nominal concentration).

Description of key information

The objective of this range finding early life stage test was to assess the effects of DHDPS on the most critical and sensitive life-stages of a freshwater fish zebrafish(Danio rerio) and to target test concentrations for a definitive extended one generation reproduction test. The exposure started with freshly fertilized eggs from a non-exposed parent population and the effect of the test substance on the apical endpoints of survival and growth was evaluated after33/34 days.

The hatch rate was not impaired in any of the concentration groups in comparison to the control group.

There was no statistically significant decrease in fish survival in any test group from end of swim-up until termination (day 5–33/34).

The mean wet weights of the surviving fish in all test groups at the end of the exposure period were not statistically significantly decreased.The total body lengths of the surviving fish in all test groups at the end of the exposure period were not statistically significantly decreased.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

10 mg/L