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

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

14 Apr - 12 Jun 2014

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP Guideline Study

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

GLP compliance:

yes (incl. QA statement)

Remarks:

Swiss Federal Office of Public Health, Consumer protection directorate, Notification authority for chemicals, Bern, Switzerland

Analytical monitoring:

yes

Details on sampling:

For the determination of the actual test item concentrations, duplicate samples were taken from each treatment at the start and at the end of the test (after 48 hours). For the 48-hour samples, the contents of the respective replicates were combined prior to sampling.

All samples were stored deep-frozen (at about -20 °C) immediately after sampling. Based on pre-experiments, the test item was found to be stable in the test water under these storage conditions.

The concentration of the test item Cyrene™ was analytically measured in one of the duplicate test medium samples of the single test concentration taken at the start and end of the test.From the control, one of the duplicate samples was analyzed per sampling time.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)- Method: The test medium was prepared by dissolving 100.1 mg of test item completely in 1000 mL of test water under intense stirring for 15 minutes at room temperature. The test medium was prepared just before the introduction of the daphnids (i.e., start of the test).

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: water flea- Source: A clone of this species (defined by the supplier as clone 5) was originally supplied by the University of Sheffield / UK in 1992. Since that time, the clone has been bred at Harlan Laboratories
- Age at study initiation (mean and range, SD): At the start of the test, the organisms used in the test were 6 to 24 hours old and were not first brood progeny.
- Method of breeding: The clone has been bred in reconstituted water of the quality identical to the water quality used in the tests (with respect to pH, main ions, and total hardness) and under temperature and light conditions identical to those of the test. During breeding, daphnids are generally fed three times a week with an algal suspension of the green algae Desmodesmus subspicatus CHODAT, Strain No. 86.81 SAG, supplied by the Collection of Algal Cultures (SAG, Institute for Plant Physiology, University of Göttingen, 37073 Göttingen / Germany) and cultivated at Harlan Laboratories under standardized conditions or a mixture of this algal suspension and a commercial fish diet (Tetra Min® Hauptfutter, supplied by TETRA-Werke, 49304 Melle / Germany).- Feeding during test: no

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Test temperature:

21 °C

pH:

7.8 - 7.9

Dissolved oxygen:

8.3 - 8.6 mg/L

Nominal and measured concentrations:

Control, 100 mg/L (nominal)

Details on test conditions:

TEST SYSTEM- Test vessel:- Type (delete if not applicable): closed; test vessels were covered with glass plates- Material, size, headspace, fill volume: 100-mL glass beakers filled with 50 mL of test medium- Aeration: Prior to the start of the study until oxygen saturation was reached. During the test period, the test water was not aerated.- No. of organisms per vessel: 5- No. of vessels per concentration (replicates): 4- No. of vessels per control (replicates): 4- Biomass loading rate: 2 mL/Daphnia

TEST MEDIUM / WATER PARAMETERS- Preparation of dilution water: Reconstituted test water according to ISO 6341 [ISO, 1996] was used in the study. It consisted of analytical grade salts dissolved in purified water at the following nominal concentrations:CaCl2 × 2H2O: 2.0 mmol/L, 294 mg/LMgSO4 × 7H2O: 0.5 mmol/L, 123 mg/LNaHCO3: 0.75mmol/L, 65 mg/LKCl: 0.075 mmol/L, 5.8 mg/LWater Hardness: 2.5 mmol/L,250 mg/L as CaCO3Alkalinity: 0.8 mmol/LThe ratio of Ca:Mg and Na:K was 4:1 and 10:1, respectively, based on molarities.- Intervals of water quality measurement: At the start and end of the test, the pH values, dissolved oxygen concentrations and water temperature were determined at each treatment. The appearance of the test medium was visually recorded at the start of the test and after 24 and 48 hours.

OTHER TEST CONDITIONS- Photoperiod: 16-hour light to 8-hour dark with a 30-minute transition period- Light intensity: 800 and 1060 Lux

EFFECT PARAMETERS MEASURED (with observation intervals if applicable): immobility after 24 and 48 hours

TEST CONCENTRATIONS- Range finding study: yes

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

24 h

Dose descriptor:

EC0

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

24 h

Dose descriptor:

EC100

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC0

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC100

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

In the control and at the test concentration of 100 mg/L, no immobilized test organisms were observed over the test period of 48 hours.

Results with reference substance (positive control):

For evaluation of the quality of the Daphnia clone and the experimental conditions, potassium dichromate is tested as a positive control twice a year. The result of the latest positive control test in March 2014 (48-hour EC50: 0.36 mg/L, Harlan Laboratories Study D88971) showed that the sensitivity of the test organisms was within the internal historical range (48-hour EC50 from 2000 to 2014: 0.36 - 1.1 mg/L).

Analytical results:

The analytically determined concentration of the test item in the test medium at the start and end of the test was 90 and 83% of the nominal value, respectively. Under the conditions of the test, the test item was sufficiently stable in the test medium over the test period of 48  hours. The reported biological results were based on the nominal concentration of the test item.

Reviewer's note: The sample has been directly injected in the GC-FID which would result in the anhydrous form of Cyrene™ being detected, however, the organisms would have been exposed to Gem Diol.

Observations and measurements:

No remarkable observations were made concerning the appearance of the test medium. The test medium was clear throughout the entire test period.

At the beginning and end of the test period, the dissolved oxygen concentrations in the test medium and control were at least 8.3 mg/L, the pH value of the test media was in the range of 7.8 to 7.9 and the water temperature during the test was maintained at 21 °C.

Validity criteria fulfilled:

yes

Conclusions:

A 48 hour EC50 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 Daphnia magna. Based on measured GC concentrations, test concentrations were within 20% of nominal therefore results 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 aquatic invertebrates:

A 48-hour EC₅₀ value of >100 mg/l and a NOEC of ≥100 mg/l (nominal) (highest concentration tested) (OECD 202)

Additional information

A 48-hour EC₅₀ value of >100 mg/l and a NOEC of ≥100 mg/l (nominal) (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 mobility of Daphnia magna. Based on measured GC concentrations, the test concentrations were within 80% of the nominal concentration, therefore the results are reported in terms of nominal concentration.

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 IUCLID Section 6.0 and CSR Section 7.0 for further discussion of the approach to chemical safety assessment for this registration substance.