2,3,3,4,4-pentafluoro-5-methoxy-2,5-bis[1,2,2,2-tetrafluoro-1-(trifluoromethyl)ethyl]tetrahydrofuran

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Reason / purpose for cross-reference:

read-across source

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 0.024 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: No immobilization in exposed organisms

Duration:

48 h

Dose descriptor:

EL50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: No immobilization in exposed organisms

Conclusions:

Novec 7700 is estimated to have no effect on Daphnia magna at its limit of water solubility (OECD 202).

Executive summary:

Novec 7700 short-term toxicity to aquatic invertebrates is assessed by readacross from Novec 7800. Toxicity of Novec 7800 to Daphnia magna under semistatic conditions was examined in a limit test according to OECD 202 guidelines. Water-accomodated fractions were made at a loading rate of ca. 100 mg/L with renewal at 24 hours. Geometric mean concentration was 0.0244 mg/L. No biological effects were observed. The EC50 based on measured concentration was >0.0244 mg/L, with an EL50 of >100 mg/L based on nominal loading rate. As explained in the justification for type of information, the structural difference between Novec 7700 and Novec 7800 is unlikely to lead to a difference in short-term toxicity to aquatic invertebrates.

Reference 2

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

30 May - 1 June 2007

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

GLP compliance:

yes

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Lot No.of test material: Lot number 1
STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: Room temperature, darkness
- Stability under test conditions: Stable

Analytical monitoring:

yes

Details on sampling:

- Sampling method: Samples were taken before and after replacement. Samples for the initial and 24-hour replacement time points were taken from the stock solution used to fill the test vessels. Samples from the 24-h and 48-h spent test solutions were taken after pooling all test solutions for that time point.
- Sample storage conditions before analysis: Samples analyzed immediately

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: A water-soluble fraction was prepared at a loading rate of ca. 100 mg/L. After stirring 48 hours at 23 °C in a closed flask with no headspace, the suspension was allowed to settle for 2 hours and liquid drawn from the middle of the flask. The withdrawn liquid was divided into the test vessels, and the test vessels were immediately covered to avoid headspace.
- Controls: Untreated test medium
- Evidence of undissolved material (e.g. precipitate, surface film, etc.): None, test solutions were clear and colorless at start of test and before and after renewal.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Strain/clone: Clone A, originally from University of Sheffield, UK
- Source: Internal laboratory subculture
- Age of parental stock: 30 days, bred for at least 14 days.
- Breeding conditions same as test conditions: Yes
- Feeding during test: No
- Age at test initiation: < 24 hrs
- Acclimation period: None

Test type:

semi-static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Hardness:

41.9 mg CaCo3/L

Test temperature:

19.8 - 20.1 °C

pH:

7.7 - 7.8

Dissolved oxygen:

8.3 - 8.4 mg/L

Salinity:

Not applicable

Conductivity:

18.3 mS/m

Nominal and measured concentrations:

Nominal: Negative control and 100 mg/L loading rate
Measured: <0.00279 mg/L, 0.0244 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: Glass petri dish, 8.5 cm diameter, 5 cm depth, filled to eliminate headspace. Volume ca. 320 mL
- Type (delete if not applicable): Closed
- Aeration: None
- Renewal rate of test solution: Once at 24 hrs
- No. of organisms per vessel: Five
- No. of vessels per concentration: Four
- No. of vessels per control (replicates): Four

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Dechlorinated municipal tap water, see Attachment 1 for details
- Total organic carbon: 0.2 mg/L
- Particulate matter: <1 mg/L suspended matter
- Metals: Ca, 11.5 mg/L; Mg, 3.2 mg/L; Al, 0.033 mg/L, Na 14.3 mg/L, K, 3.7 mg/L. Others below limit of determination
- Pesticides: below limit of determination
- Chlorine: Free chlorine below limit of determination
- Alkalinity: 35 mg/L
- Ca/mg ratio: 3.59 (mass basis)
- Culture medium different from test medium: No
- Intervals of water quality measurement: Most recent analysis five months before test

OTHER TEST CONDITIONS
- Adjustment of pH: No
- Photoperiod: 16 hours light:8 hours dark

EFFECT PARAMETERS MEASURED: Mobility at 24 and 48 hours

RANGE-FINDING STUDY
- Test concentrations: Negative control and 100 mg/L loading rate.
- Results used to determine the conditions for the definitive study: No toxicity observed.

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 0.024 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: No immobilization in exposed organisms

Duration:

48 h

Dose descriptor:

EL50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: No immobilization in exposed organisms

Details on results:

- Abnormal responses in exposed organisms: None:
- Mortality of control: None
- Other adverse effects control: None
- Abnormal responses: None
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: None
- Effect concentrations exceeding solubility of substance in test medium: Yes

Results with reference substance (positive control):

A 48-hour acute immobilization test of K2Cr2O7 with the test organisms was conducted 50 days prior to the current study to confirm the reproducibility of the test conditions. The 48-hour EC50 of K2Cr2O7 was 0.270 mg/L. This value was within the normal range in this laboratory [mean ± SD: 0.236 ± 0.057 mg/L (n=58)].

Table 1, Concentration of Novec 7800, dissolved (measured after sample was allowed to rest 24 hours before analysis)

Nominal concentration (mg/L)	Measured concentration (mg/L)
	Initial	24 h, spent	24 h, renewal	48 h	Geometric mean
0 mg/L (Control)	<0.00279	<0.00279	<0.00279	<0.00279	─
100 mg/L	0.0234	0.0105 (44.7%)	0.0494	0.0294 (59.5%)	0.0244

 

Table 2, Concentration of Novec 7800, suspended (measured immediately after sample was collected)

Nominal concentration (mg/L)	Measured concentration (mg/L)
	Initial	24 h, spent	24 h, renewal	48 h	Geometric mean
0 mg/L (Control)	<0.00279	<0.00279	<0.00279	<0.00279	─
100 mg/L	0.0772	0.0156	0.0935	0.0398	0.0460

Results were reported based on the "dissolved" concentration.

Validity criteria fulfilled:

yes

Remarks:

<10% of controls immobilized or trapped at water surface (0%), DO >60% saturation (no significant decline)

Conclusions:

Novec 7800 has no effect on D. magna at its limit of water solubility (OECD 202)

Executive summary:

Toxicity of Novec 7800 to Daphnia magna under semistatic conditions was examined in a limit test according to OECD 202 guidelines. Water-accomodated fractions were made at a loading rate of ca. 100 mg/L with renewal at 24 hours. Geometric mean concentration was 0.0244 mg/L. No biological effects were observed. The EC50 based on measured concentration was >0.0244 mg/L, with an EL50 of >100 mg/L based on nominal loading rate.

The test was conducted according to an internationally accepted test guideline under GLP. Considerable test substance was lost during the experiment; however, as a volatile and insoluble material some losses are considered unavoidable. The study is deemed reliable with restriction and suitable for use in Risk Assessment, Classification & Labeling, and PBT Analysis.

Description of key information

Novec 7700 is estimated to have no effect on Daphnia magna at its limit of water solubility (OECD202)

Additional information

Novec 7700 short-term toxicity to aquatic invertebrates is assessed by readacross from Novec 7800. Toxicity of Novec 7800 to Daphnia magna under semistatic conditions was examined in a limit test according to OECD 202 guidelines. Given a loading rate of 100 mg/L, the geometric mean measured concentration in the test medium was 0.0244 mg/L. No toxicity was observed. As explained in the Analog Reporting Format justifying the readacross, the structural difference between Novec 7700 and Novec 7800 is unlikely to lead to a difference in short-term toxicity to aquatic invertebrates.