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Ecotoxicological information

Short-term toxicity to aquatic invertebrates

Administrative data

Endpoint:
short-term toxicity to aquatic invertebrates
Type of information:
experimental study
Adequacy of study:
key study
Study period:
16 Apr 2007 - 31 May 2007
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Guideline study under GLP, test substance could not be maintained in solution, reasonable efforts were made maintain concentrations over the whole test duration

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2007
Report Date:
2007

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)
Deviations:
no
Qualifier:
according to
Guideline:
EU Method C.2 (Acute Toxicity for Daphnia)
Deviations:
no
Qualifier:
according to
Guideline:
ISO 6341 (Water quality - Determination of the Inhibition of the Mobility of Daphnia magna Straus (Cladocera, Crustacea))
Deviations:
no
Qualifier:
according to
Guideline:
other: Guidance document on aquatic toxicity testing of difficult substances and mixtures, OECD series on testing and assessment number 23, December 14, 2000.
Deviations:
no
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): MTDID 7145
- Substance type: Multiconstituent substance
- Physical state: Clear, colourless liquid
- Analytical purity: 94.5%
- Lot/batch no.: 142072:43
- Expiration date of the lot/batch: 30 Dec 2007
- Stability under test conditions: Stable
- Storage condition of test material: At room temperature in the dark

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
- Concentrations: WAFs prepared at loading rates of 1.0, 10 and 100 mg/L for the rangefinding test, and 100 mg/L only for the limit test.

- Sampling method: Aliquots (10 mL) were taken from the appoximate center of the test vessels. Samples were taken of freshly-prepared test solution at start of test and at renewal (24 hours), and of spent solution (before renewal) at 24 hours and at test completion. A single sample was taken at the start of the test, duplicates at other time points. At the end of each refreshment period, the replicates were pooled at each concentration before sampling.
- Sample storage conditions before analysis: Samples were analyzed day of sampling

Test solutions

Vehicle:
no
Details on test solutions:
PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: Water accomodated fraction. Test solutions were prepared daily. A loading rate of 100 mg/L was stirred for approximately 1 hour in air-tight vessels. After a stabilisation period of 5-25 minutes, the Water Accommodated Fraction (WAF) was collected by siphoning and used for the test. The final test solutions were all clear and colourless.
- Controls: Blank
- Evidence of undissolved material (e.g. precipitate, surface film, etc): None

Test organisms

Test organisms (species):
Daphnia magna
Details on test organisms:
TEST ORGANISM
- Common name: Water flea
- Strain: Daphnia magna Straus, 1820
- Source: In-house laboratory culture
- Age at study initiation (mean and range, SD): < 24 hours
- Method of breeding: Acyclical parthenogenesis. Breeding batch started by placing approximately 250 daphnids less than 3 days old into 5 liters of M7 medium in an all-glass culture vessel. Cultures maintained for a maximum age of 4 weeks. After the first 7 days, cultures are renewed by replacement of half of the medium twice weekly. Cultures are maintained at 18 - 22 deg. C and fed daily with a suspension of freshwater algae.
- Feeding during test: None

Study design

Test type:
semi-static
Water media type:
freshwater
Limit test:
yes
Total exposure duration:
48 h

Test conditions

Hardness:
180 mg CaCO3 / L
Test temperature:
19.7 °C - 21.2 °C
pH:
7.5 - 8.0
Dissolved oxygen:
8.6 - 9.0 mg/L
Salinity:
NA
Nominal and measured concentrations:
WAF based on 100 mg/L loading rate
Average measured concentration, 0.065 mg.L
Details on test conditions:
TEST SYSTEM
- Test vessel: 100-mL sealed all-glass containers. Fill volume was 100 mL. No headspace is described.
- Aeration: None
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): four
- No. of vessels per control (replicates): four

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Water used to make growth medium was purified by reverse osmosis.
- Culture medium different from test medium: no, standard M7 medium used throughout.

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

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Immobilization: Daily
-Mortality: Daily

TEST CONCENTRATIONS
- Spacing factor for test concentrations: One concentration tested
- Justification for using less concentrations than requested by guideline: Limit test
- Range finding study: Yes
- Test concentrations: WAFs based on 1.0 mg/L, 10 mg/L and 100 mg/L loading rates
- Results used to determine the conditions for the definitive study: Yes. No significant immobilization at any concentration tested.
Reference substance (positive control):
yes
Remarks:
Potassium dichromate, reference test done 12 weeks prior to FC-770 study

Results and discussion

Effect concentrations
Duration:
48 h
Dose descriptor:
EC50
Effect conc.:
> 0.065 mg/L
Nominal / measured:
meas. (geom. mean)
Conc. based on:
act. ingr.
Basis for effect:
mobility
Remarks on result:
other: Corresponds to 100 mg/L initial loading rate
Details on results:
Measured concentrations in the limit test are shown in Table 1. One immobilized organism was observed in the exposed group during the test period v. none in controls (Table 2). The NOEC was 0.065 mg/L, which corresponds to the 100 mg/L initial loading rate.

In the rangefinding test, 10% immobilization was seen in both controls and the 100 mg/L loading rate group (Table 3).

- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: The highest attainable concentration in the test solutions was very near the solubility limit in this medium and therefore FC-770 could not always be quantified in all test solutions. Concentration of test substance was < LOQ in all blanks and in 24-hour-old test solutions sampled before replacement. However, instrument response was below quantifiable range in one of three tests of fresh medium (Table 1). The Limit of Detection is not defined in the study report. From the chromatograms (See Figures 1 and 2), it is apparent that treated medium still has peaks corresponding to FC-770 after 24 hours, although in one case the blank also had a peak in the corresponding range. Because flame ionization does not provide confirmation of the analyte of interest and because the height of noise peaks is roughly equal to the height of peaks in the correct positions in some chromatograms, the presence of FC-770 in these samples cannot be unambiguously established.

The average concentration during the assay was calculated by taking the geometric mean of initial and final concentrations of each the two test solutions (Day 0 to Day 1 before replacement, Day 1 after replacement to Day 2). The arithmatic mean of the two geometric means was then calculated to obtain the average concentration during the test. The average of the Day 1 before replacement concentrations was used to avoid improperly weighting the final concentration
- Effect concentrations exceeding solubility of substance in test medium: Yes
Results with reference substance (positive control):
In a test of potassium dichromate conducted 12 weeks prior to the FC-770 test, a 48-h EC50 of 0.34 mg/L was observed. This EC50 is within the range of values for reference tests of D. magna performed by the testing lab.

Any other information on results incl. tables

Table 1, Concentrations of FC-770 in the test medium

Day of sampling (age)

Concentration

Loading rate (mg/I)

Analysed(mg/l)

0

0

<LOQ1

 

100

0.1

 

 

1 (old)

0

<LOQ

 

0

<LOQ

 

100

<LOQ

 

100

<LOQ

 

 

1 (fresh)

0

<LOQ

 

0

<LOQ

 

100

<LOQ

 

100

0.1

 

 

2 (old)

0

<LOQ

 

0

<LOQ

 

100

<LOQ

 

100

<LOQ

1, <LOQ, concentration less than Limit of Quantitation (0.1 mg/L)

Table 2, Acute immobilisation of daphnia after 24 and 48 hours in the limit test

Loading rate (mg/L)

Vessel number

Number Daphnia exposed

Response at 24 h

Response at 48 h

Number

% of Total

Number

% of Total

control

A

5

0

0

0

0

 

B

5

0

0

 

C

5

0

0

 

D

5

0

0

 

 

100

A

5

0

0

0

5

 

B

5

0

0

 

C

5

0

0

 

D

5

0

1

 

Table 3, Acute immobilisation of daphnia after 24 and 48 hours in the rangefinding test

Loading rate (mg/L)

Vessel number

Number Daphnia exposed

Response at 24 h

Response at 48 h

Number

% of Total

Number

% of Total

control

A

5

0

0

1

10

 

B

5

0(1)*

1

A

5

0

0

0

0

 

B

5

0

10

A

5

0

0

0

0

 

B

5

0

100

A

5

1

10

1

10

 

B

5

0

 

* Number of daphnids in parentheses is for organisms trapped at the surface. These daphnids were reimmersed into the respective solution before recording of immobility.

 

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Remarks:
<10% immobilization in controls, DO >3 mg/L
Conclusions:
Due to the low water solubility and high volatility of FC-770, concentration levels that might be
toxic for Daphnia magna could not be reached.
Executive summary:

The toxicity of FC-770 to Daphnia magna (water flea) was assessed in a semi-static test conducted according to OECD TG202. The test was performed as a limit test after a rangefinding test indicated no toxicity in water accomodated fractions (WAFs) made using loading rates of 1.0, 10, and 100 mg/L. The limit test used a WAF made with a loading rate of 100 mg/L. FC-770 concentrations in 24 hour-old test solutions were below the limit of quantitation (LOQ), and in one case the fresh replacement solution was <LOQ as well. Limited immobilization (5%) was observed in the exposed organisms. The 48-hour EC50 of FC-770 to Daphnia magna was >0.065 mg/L. The NOEC was 0.065 mg/L. No toxicity was seen at the initial 100 mg/L loading rate, which is above the limit of water solubility.

The study was conducted under accepted guidelines and according to GLP criteria. The concentration of FC-770 could not be maintained above the limit of quantitation. However, reasonable efforts were made to obtain and maintain the highest possible concentration over the whole test duration. Therefore, the study is classified as reliable with restrictions.

Results Synopsis

Test Type: Semi-Static

EC50:  >0.065 mg/L                        95% C.I.:  NA

NOEC: 0.065 mg/L                 Probit Slope:  NA