6-diazo-5,6-dihydro-5-oxonaphthalene-2-sulphonyl chloride

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:

May 10 - June 15, 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

Samples (ca 20 mL) were taken from the control and test concentration at 0 hours (fresh media), and 96 hours (old media) for analysis.
In each case, duplicate samples were taken, one for chemical analysis and one as a ‘back-up’ should further analysis be required.

Vehicle:

yes

Details on test solutions:

At the start of the test, 1600.19 mg of the test substance was added to 20 L of treated mains water to give 80 mg/L test concentration. This concentration was then stirred for ca 18 hours (to allow the test substance to degrade to F6-chloride degradation products), prior to filtration through a 0.2 μm capsule filter. The control was prepared by adding treated mains water only to the control vessel.

Test organisms (species):

Oncorhynchus mykiss (previous name: Salmo gairdneri)

Details on test organisms:

Healthy Oncorhynchus mykiss (rainbow trout) were supplied by Northern Trout, United Kingdom, details of which are maintained in Smithers Viscient (ESG) Ltd. records.
The fish were acclimatised to the test conditions for at least 12 days prior to testing. The mortality rate of the stock batch of fish was 0% in the 7 days prior to the definitive test.

Fish were selected, at random (avoiding some unusually large fish which were not representative of the majority of the batch – not considered to impact study integrity as it is normal for more aggressive fish to grow more quickly due to aggression during feeding), from the holding tank and allocated to the test vessels at the start of each phase of testing. The fish were not fed for at least 24 hours before the start of the test and were not fed throughout the test.

The total length and wet weight of ten randomly selected fish from the stock fish were determined periodically to ensure fish were of a suitable size and weight for testing and to ensure the correct testing volumes were used so as not to exceed the recommended loading rate.

At the end of the test, the total length and wet weight of a random sub-sample of ten fish were determined, selected at random from those used in the test.

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

96 h

Hardness:

86 mg/L

Test temperature:

15 ± 2ºC)

pH:

adjusted @7 using NaOH

Dissolved oxygen:

Control: 96 - 103 %
Test: 93 - 98%

Nominal and measured concentrations:

80 mg/L (nominal)
51.6 mg/L (measured @ 0 hours)
57.4 mg/L (measured @ 96 hours)

Key result

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

54.5 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

other: degradation product

Basis for effect:

mortality (fish)

Key result

Duration:

96 h

Dose descriptor:

EC50

Effect conc.:

> 54.5 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

other: degradation product

Basis for effect:

mortality (fish)

Details on results:

Based on mean measured concentration, the 96-hour LC50 value was estimated to be > 54.5 mg/L.
The corresponding NOEC value was 54.5 mg/L.
The validity criteria for control mortality (≤10%) and dissolved oxygen (≥60%) were both satisfied. The test is, therefore, considered valid.

Validity criteria fulfilled:

yes

Conclusions:

Based on mean measured concentration, the 96-hour LC50 value was estimated to be > 54.5 mg/L. The corresponding NOEC value was 54.5 mg/L.

Description of key information

OECD 203: NOEC 54.5 mg/L , EC50 (96 h) > 54.5 mg/L (measured mean concentrations)

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

54.5 mg/L