Registration Dossier

Administrative data

Endpoint:
sediment toxicity: short-term
Type of information:
experimental study
Adequacy of study:
supporting study
Study period:
18 June 2007 to 22 June 2007
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Comparable to guideline study with acceptable restrictions

Data source

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

Materials and methods

Test guidelineopen allclose all
Qualifier:
equivalent or similar to guideline
Guideline:
other: ASTM Standard E729-96. 1996. Standard Guide for Conducting Acute Toxicity Tests on Test Materials with Fishes, Macroinvertebrates, and Amphibians.
Deviations:
not specified
Qualifier:
equivalent or similar to guideline
Guideline:
other: Study report also cites EPA 600/R-99/064: Method for Measuring the Acute Toxicity of Effluents and Receiving Waters to Freshwater Invertebrates
Deviations:
not specified
GLP compliance:
no

Test material

Constituent 1
Reference substance name:
PFBA (degradation product)
IUPAC Name:
PFBA (degradation product)
Details on test material:
Name of test material (as cited in study report): Perfluorobutyric acid, potassium salt; 2,2,3,3,4,4,4-Heptafluorobutanoic acid, potassium salt; PFBA, K salt; L16149
- Molecular formula (if other than submission substance): C4F7O2K
- Molecular weight (if other than submission substance): 252.13
- Smiles notation (if other than submission substance): [K+].FC(F)(C(F)(F)C([O-])=O)C(F)(F)F
- InChl (if other than submission substance): InChI=1/C4HF7O2.K/c5-2(6,1(12)13)3(7,8)4(9,10)11;/h(H,12,13);/q;+1/p-1

- Substance type: pure active substance
- Physical state: white solid
- Analytical purity: 98.65%
- Stability under test conditions: Stable
- Storage condition of test material: Frozen
- Other: potassium salt of perfluorobutyric acid

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
Concentrations: Only samples from the two highest test concentrations (1000 mg/L and 10,000 mg/L) were analyzed (see Table 1).
- Sampling method: At test termination on day 4, samples of test solution were collected from each test chamber and pooled by treatment group for analysis of test substance concentrations. All samples were collected at mid-depth, placed in plastic vials, and stored until analysis.
- Sample storage conditions before analysis: Refrigerated

Test substrate

Vehicle:
no
Details on sediment and application:
PREPARATION OF SPIKED WATER
- Details of spiking: Individual test solutions were prepared on day 0 in well water at nominal concentrations of 10, 100, 1000 and 10000 mg a.i./L, by mixing a calculated amount of PFBA directly into test chambers with dilution water. The test solution was mixed by stirring, and appeared clear and colorless after mixing. All test solutions were adjusted to 100% active ingredient during preparation, based on the test substance purity (98.65%).
- Controls: Negative control (test dilution water) only
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): None

Test organisms

Test organisms (species):
Chironomus dilutus (previous name: Chironomus tentans)
Details on test organisms:
TEST ORGANISM
- Common name: Chironomid
- Source: Environmental Consulting and Testing, Superior, WI
- Age at study initiation (mean and range, SD): 10 days (hatched June 8, 2007)

- Feeding during test: Days 0 and 2 only.
- Food type: 4 g/L suspension of Tetramin® flake food

ACCLIMATION
- Acclimation period: 10 days
- Type and amount of food: 56 g/L suspension of Tetramin® flake food

Study design

Study type:
laboratory study
Test type:
static
Water media type:
freshwater
Type of sediment:
artificial sediment
Limit test:
no
Exposure duration
Duration:
96 h
Exposure phase:
total exposure duration
Remarks:
Rangefinding test

Test conditions

Hardness:
134 mg/L as CaCO3
Test temperature:
23 ± 2 °C
pH:
8.0 - 8.6
Dissolved oxygen:
8.1 - 9.2 mg/L during acclimation/holding
Salinity:
Not applicable
Ammonia:
No data
Nominal and measured concentrations:
Nominal concentrations: Negative control, 10, 100, 1000, and 10,000 mg/L
Measured concentrations: 1070 and 10,602 mg/L (for 1000 and 10,000 mg/L nominal, respectively)
Details on test conditions:
TEST SYSTEM
- Test container (material, size): 30 mL plastic beakers containing a layer of sand as substrate
- Sediment volume: Not reported
- Overlying water volume: 20 mL (includes pore water)
- Depth of sediment and overlying water: Not reported
- Aeration: No
- Replacement of evaporated test water, if any: Not reported

EXPOSURE REGIME
- No. of organisms per container (treatment): One
- No. of replicates per treatment group: Ten
- No. of replicates per control / vehicle control: Ten
- Feeding regime:
- Type and preparation of food: 56 g/L suspension of Tetramin® flake food during holding, 4 g/L on test days 0 and 2.
- Amount of food: Not reported

OVERLYING WATER CHARACTERISTCS
- Type of water (e.g. deionized, ground water, sea water, Elendt medium acc. to OECD 219): groundwater
- Location: Well located on the Wildlife International Ltd. site.
- Filtration: Not reported
- Alkalinity: 181 mg/L as CaCO3
- Conductivity: 311 μmhos/cm

CHARACTERIZATION OF SEDIMENT
- % sand: 100%

OTHER TEST CONDITIONS
- Adjustment of pH: None
- Photoperiod: 16-hours light; 8-hours dark with 30-minute transition periods of low light intensity
- Light intensity: Cool-white fluorescence light, intensity not reported

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Mortality, clinical signs of toxicity (daily)

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 10-fold
- Justification for using less concentrations than requested by guideline: Rangefinding study
Reference substance (positive control):
no

Results and discussion

Effect concentrations
Duration:
96 h
Dose descriptor:
LC50
Effect conc.:
> 10 000 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
mortality
Details on results:
The 96-hour NOEC was given as 10,000 mg/L. One organism died at each of 10 mg/L and 10,000 mg/L.
- Behavioural abnormalities: Appeared normal (See table 2)
- Mortality of control: None
Results with reference substance (positive control):
Not applicable
Reported statistics and error estimates:
LC50 based on visual inspection

Any other information on results incl. tables

Table 2, Summary of 96-Hour Acute Toxicity of PFBA to the Chironomid (Chironomus tentans) Under Static Exposure Conditions

Nominal Concentration (mg/L)

Number Dead in 24 Hours / Cumulative Number Dead / Number Originally Exposed (Observations1)

Cumulative percent mortality

5 Hours

24 Hours

48 Hours

72 Hours

96 Hours

Negative Control

0 / 0 / 10 (10AN)

0 / 0 / 10 (10AN)

0 / 0 / 10 (10AN)

0 / 0 / 10 (10AN)

0 / 0 / 10 (10AN)

0

 

 

10

0 / 0 / 10 (10AN)

0 / 0 / 10 (10AN)

1 / 1 / 10 (9AN)

0 / 1 / 10 (9AN)

0 / 1 / 10 (9AN)

10

 

 

100

0 / 0 / 10 (10AN)

0 / 0 / 10 (10AN)

0 / 0 / 10 (10AN)

0 / 0 / 10 (10AN)

0 / 0 / 10 (10AN)

0

 

 

1000

0 / 0 / 10 (10AN)

0 / 0 / 10 (10AN)

0 / 0 / 10 (10AN)

0 / 0 / 10 (10AN)

0 / 0 / 10 (10AN)

0

 

 

10,000

0 / 0 / 10 (10AN)

1 / 1 / 10 (9AN)

0 / 1 / 10 (9AN)

0 / 1 / 10 (9AN)

0 / 1 / 10 (9AN)

10

1, Observations: AN = appear normal.

LC50:

>10,000 mg/L

>10,000 mg/L

>10,000 mg/L

>10,000 mg/L

95% Confidence Interval

Statistical Method

Visual interpretation

Visual interpretation

Visual interpretation

Visual interpretation

 

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
The 96-hour LC50 of PFBA-K salt to Chironomid (Chironomus tentans) was >10,000 mg/L
Executive summary:

The toxicity of n-PFBA to Chironomus tentans (Midge) was assessed in a static method. PFBA is a strong acid and is entirely deprotonated at environmental pH. The toxicity was measured using the potassium salt of PFBA. This procedure is equivalent to a toxicity test utilizing neutralized PFBA acid at nominal concentrations of 10, 100, 1000 and 10000 mg/L plus negative control. The 96-hour LC50 of PFBA was >10,000 mg/L. The 96-hour NOEC was given as 10,000 mg/L. PFBA is not acutely toxic according to GHS criteria.

The test was a range-finding test, with measured concentrations, on the aquatic toxicity of perfluorobutyric acid. As such, this study sets an approximate value for further toxicity test. This test is therefore classified as reliable with restrictions.

Results Synopsis

Test Type: static

LC50: >10,000 mg/L       95% C.I.: not applicable

NOEC: 10,000 mg/L       Probit Slope: not applicable