Registration Dossier

Ecotoxicological information

Short-term toxicity to aquatic invertebrates

Currently viewing:

Administrative data

Link to relevant study record(s)

Referenceopen allclose all

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:
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.

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:
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)

Key value for chemical safety assessment

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.