6,8-Dioxabicyclo[3.2.1]octan-4-one, (1S,5R)-

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:

2017-11-01 to 2018-07-13

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

- Concentrations: limit test, 0 and 100 mg/L
- Sampling method: Water samples were taken from the control and test group, from fresh and old media throughout the 96 Hour test period, for quantitative analysis. A duplicate set of samples at 0 and 72 hour (fresh media) and 24 and 96 hour (old media) were taken and stored frozen for further analysis if necessary.
- Sample storage conditions before analysis: All samples were stored frozen prior to analysis.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: An amount of test item (2000 mg) was dissolved in test water and the volume adjusted to 2 liters to give a 1000 mg/L stock solution. The stock solution was inverted several times to ensure adequate mixing and homogeneity.
A dilution was made from the stock solution to give 20 litres of media at the test concentration of 100 mg/L.
The solution was mixed with a flat bladed stirrer for approximately 1 minute to ensure adequate mixing and homogeneity.


- Evidence of undissolved material (e.g. precipitate, surface film, etc.): visual observations were done and no evidence was noted

Test organisms (species):

Oncorhynchus mykiss (previous name: Salmo gairdneri)

Details on test organisms:

TEST ORGANISM
- Common name: rainbow trout
- Strain: NA
- Source: Brow Well Fisheries Limited, Hebden, near Skipton, Yorkshire, UK
- Age at study initiation (mean and range, SD): juveniles
- Length at study initiation (length definition, mean, range and SD): mean standard length of 5.0 cm (standard deviation = 0.29) at the end of the study
- Weight at study initiation (mean and range, SD): mean body weight of 1.2 g (standard deviation = 0.29) at the end of the study
- Method of breeding: not reported
- Maintenance of the brood fish: not reported

ACCLIMATION
- Acclimation period: 14 May 2018 to 21 May 2018
- Acclimation conditions (same as test or not): same as test
- Type and amount of food during acclimation: The stock fish were fed commercial trout pellets which was discontinued approximately 27 hours prior to the start of the definitive test.
- Feeding frequency during acclimation: not reported
- Health during acclimation (any mortality observed): There was no mortality in the 7 days prior to the start of the test


FEEDING DURING TEST
Not fed during study

Test type:

semi-static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

96 h

Hardness:

140 mg/L as CaCO3

Test temperature:

14 degC to 15 degC

pH:

7.6-8.0

Dissolved oxygen:

9.5-10.3 mg/L

Salinity:

NA

Conductivity:

345 μS/cm at 20 °C

Nominal and measured concentrations:

nominal: control and 100 mg/L
measured: 0 and between 88-92 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: tank
- Type (delete if not applicable): The test vessels were covered to reduce evaporation
- Material, size, headspace, fill volume: 25 to 30 L glass tank, containing 20 L test medium
- Aeration: aerated via narrow bore glass tubes
- Renewal rate of test solution (frequency/flow rate): 24 hours renewal (semi-static)
- No. of organisms per vessel: 7
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1
- Biomass loading rate: 0.41 g body weight/L

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Laboratory tap water was dechlorinated by passage through an activated carbon filter (Purite Series 500) and partly softened (Elga Nimbus 1248D Duplex Water Softener).
- Total organic carbon: not reported
- Particulate matter: not reported
- Metals:
Aluminium 7.46 mg Al/L
Fluoride 0.24 mg F/L
Iron 19.9 μg Fe/L
Manganese 2.9 μg Mn/L
Nitrate 7.61 mg NO3/L
Copper 0.02 mg Cu/L
Lead 0.51 μg Pb/L
Nickel 3.1 μg Ni/L

- Pesticides: 0 μg/L
- Chlorine: 0.32 mg/L
- Alkalinity: pH 7.66
- Ca/mg ratio: not reported
- Culture medium different from test medium: no
- Intervals of water quality measurement: The water temperature, pH and dissolved oxygen concentrations were recorded daily throughout the test. The measurements at 0 hours, and after each test media renewal at 24, 48 and 72 hours

OTHER TEST CONDITIONS
- Adjustment of pH: none
- Photoperiod: 16 hours light and 8 hours darkness with 20 minute dawn and dusk transition periods
- Light intensity: nor reported

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Any mortalities and sub-lethal effects of exposure were recorded at 1, 3, 6, 24, 48, 72 and 96 hours after the start of exposure.

TEST CONCENTRATIONS
- Spacing factor for test concentrations: NA
- Justification for using less concentrations than requested by guideline: NA
- Range finding study
The EC50 values obtained for both the Algal Growth Inhibition study and the Acute Toxicity to Daphnia magna study (Harlan study numbers D87406 and D87417, respectively) were greater than 100 mg/L.

Reference substance (positive control):

no

Key result

Duration:

96 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: mean measured concentration 88-92 mg/L

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: mean measured concentration 88-92 mg/L

Details on results:

- Behavioural abnormalities:
- Observations on body length and weight: only final values reported
- Other biological observations: There were no sub lethal effects of exposure observed in the test.
- Mortality of control: 0
- Other adverse effects control: none reported
- Abnormal responses: none reported
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: The test item preparations were observed to be clear colorless solutions throughout the test.
- Effect concentrations exceeding solubility of substance in test medium: not applicable

Reported statistics and error estimates:

An estimate of the LC50 values was given by inspection of the mortality data.

Sublethal observations / clinical signs:

There were no mortalities in seven fish exposed to a test concentration of 100 mg/L for a period of 96 hours. Inspection of the mortality data gave the following results:

Time (Hour)	LC50 (mg/L)
1	>100
3	>100
6	>100
24	>100
48	>100
72	>100
96	>100

Conclusions:

A 96 hour LC50 value of >100 mg/l and a NOEC of ≥100 mg/l (nominal) (highest concentration tested) have been determined for the effects of Cyrene™ (CAS 53716-82-8) on mobility of Oncorhynchus mykiss. Based on measured HPLC concentrations, test concentrations were within 20% of nominal therefore effect values are based on nominal concentrations.

In view of the properties of the substance, it is thought that the organisms were exposed to the Gem Diol form of the substance.

Refer to the discussion in IUCLID Section 6.0 for further discussion of the approach to chemical safety assessment for this registration substance.

Description of key information

Short-term toxicity to fish: 96-hour LC₅₀ >100 mg/l and a NOEC of ≥100 mg/l (nominal) (limit test) (OECD Guideline 203 (Fish, Acute Toxicity Test))

Additional information

A 96-hour LC₅₀ value of >100 mg/l and a NOEC of ≥100 mg/l (limit test) have been determined for the effects of (1S,5R)-6,8-dioxabicyclo[3.2.1]octan-4-one (CAS 53716-82-8) on mortality of Oncorhynchus mykiss. Based on measured HPLC concentrations, test concentrations were within 20% of nominal therefore results are based on nominal concentrations.

It is thought that the organisms were exposed to the Gem Diol form of the substance.

Refer to IUCLID Section 6 and CSR Section 7 for further discussion of the approach to chemical safety assessment for this registration substance.