1,1,2,2,3,3,4-heptafluorocyclopentane

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:

From 1997-12-09 to 1998-01-16

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

1984

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Purity: 98.18%
Batch No.: 9705-2A

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 6.25, 12.5, 25, 50, 100 mg/L
- Sampling method: At the start of the definitive test, triplicate samples (20 mL) were taken from the freshly-prepared dilutions of test material remaining in each preparation flask. After 48 hours, the contents of the test vessels at each level were pooled and further samples taken for analysis.

Vehicle:

no

Details on test solutions:

An aqueous stock preparation was prepared by injecting the appropriate volume of test material directly into dilution water. The stock was diluted appropriately to obtain the test concentrations.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Source: University of Sheffield, England
- Age at study initiation: less than 24 hours old - Culture method:
Culture vessels: two-litre glass beakers with loose-fitting glass covers.
Temperature: 20±2°C.
Light: 16 hours light, supplied by overhead fluorescent tubes, and eight hours darkness.
Water change: replaced twice each week
- Feeding regime: fed (at a density of 2 to 8 E+05 cells per mL) at least five times each week with suspensions of the unicellular green alga Chlorella vulgaris.

PROCEDURE FOR OBTAINING JUVENILE DAPHNIA
The day before the start of each test, all juvenile Daphnia were removed from the laboratory cultures. The following morning, any juveniles produced by the gravid (egg-bearing) Daphnia were removed from the culture vessels and held in a separate holding vessel; these animals, which were less than 24 hours old, were used in the test. Between the time of isolation and use in the definitive test, the juveniles were held in water at 19.6 to 19.8°C.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

50 mg CaCO3/L

Test temperature:

19.7 - 20.4 °C

pH:

7.6 - 7.8

Dissolved oxygen:

95 - 99 %ASV

Nominal and measured concentrations:

Nominal: 6.25, 12.5, 25, 50, 100 mg/L
Measured: 4.1 1, 7.52, 15.2, 32.4, 90.9 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: 120-mL capacity glass bottles that were completely filled with media and sealed with a Teflon disc, secured with an aluminum cap
- Type (delete if not applicable): closed
- Aeration: no
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: reconstituted water prepared in accordance with Elendt M4, refert to "Appendix 2 Preparation of the reconstituted dilution water (Elendt M4)" in attached background material section.
- Intervals of water quality measurement:
The concentrations of sodium, potassium, calcium and magnesium in a sample of dilution medium typically used in this type of test are determined every three months.

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16 h light/ 8h darkness

EFFECT PARAMETERS MEASURED:
Observations of the Daphnia were made 24 and 48 hours after the start. The appearance of the test media was noted at intervals during the test.

VEHICLE CONTROL PERFORMED: no

RANGE-FINDING STUDY
- Test concentrations: 1, 10 and 100 mg/L
- Results used to determine the conditions for the definitive study:
48-hour EC50 fell between 27.0 and 113 mg/L (measured levels).
The results of chemical analysis indicated that the measured concentrations were lower than intended, so a further two tests were conducted in which the method used to prepare the test media was amended; the results of chemical analysis from the third test indicated that the intended exposure concentration (100 mg/L) had been achieved.

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

63.3 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: with 95% confidence limits of 32.4 and 90.9 mg/L

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

32.4 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

- Effects:
At 24 hours, only 35% of the Daphnia were immobilised.
After 48 hours, at the highest test concentration (90.9 mg/L), 85% immobility was noted.
- Chemical analysis:
At the lowest concentration (6.25 mg/L) results were variable, presumably due to their proximity to the limit of detection of the analytical method (3.75 mg/L); the measured concentration was estimated to range from 4.0 mg/L at the start to 4.22 mg/L after 48 hours. At 12.5 to 100 mg/L, the measured levels of test item ranged 72 and 116% of their nominal values at the start; after 48 hours, the measured levels had decreased to between 61 and 71 % of their starting values.

Results with reference substance (positive control):

- Results with reference substance valid? yes
- ECx: 48-hour EC50 to Daphnia magna was 0.67 mg/L; this was within the range typically obtained in this laboratory (0.3 to 0.8 mg/L).

Reported statistics and error estimates:

The 48h EC50 value was obtained by non-linear interpolation between the two concentrations which bracket the 50% effect level and the confidence limits were derived using the Binomial test.

Validity criteria fulfilled:

yes

Conclusions:

The 48h short term EC50 of the test material to Daphnia magna is 63.3 mg/L and the 48h NOEC was 32.4 mg/L.

Executive summary:

The acute toxicity of test item to Daphnia magna was assessed under static exposure conditions over a period of 48 hours using methods based on OECD Procedure 202.

Groups of twenty Daphnia were exposed to test item at nominal concentrations of 6.25, 12.5, 25, 50 and 100 mg/L or to dilution medium alone (Elendt M4). Because the test material was known to be volatile nature, it was added directly to water and the test vessels were completely filled leaving no head space and sealed throughout the test.

At 24 hours, only 35% of the Daphnia were immobilised. After 48 hours, at the highest test concentration (90.9 mg/L), 85% immobility was noted.

The 48h short term EC50 of the test material to Daphnia magna is 63.3 mg/L and the 48h NOEC was 32.4 mg/L.

Description of key information

The acute toxicity of test item to Daphnia magna was assessed under static exposure conditions over a period of 48 hours using methods based on OECD Procedure 202.

The 48h short term EC50 of the test material to Daphnia magna is 63.3 mg/L and the 48h NOEC was 32.4 mg/L.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

63.3 mg/L