Potassium 1,1,2,2,3,3,4,4,4-nonafluorobutane-1-sulphonate

Long-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

long-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

07 - 28 Feb 2001

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EPA OPPTS 850.1300 (Daphnid Chronic Toxicity Test)

Qualifier:

according to guideline

Guideline:

OECD Guideline 211 (Daphnia magna Reproduction Test)

Qualifier:

equivalent or similar to guideline

Guideline:

other: ASTM Standard E 1193-96, Standard Guide for Conducting Renewal Life-Cycle Toxicity Tests with Daphnia magna

GLP compliance:

yes

Specific details on test material used for the study:

- Source and lot/batch No.of test material: L-7038 Lot 2
- Purity: 97.3%
- Expiration date of the lot/batch: 17 Jan 2002
- Storage condition of test material: Ambient room temperature
- Stability under test conditions: Stable

Analytical monitoring:

yes

Details on sampling:

Details on sampling
- Concentrations: All; sampled at test initiation, and weekly from new and old test solutions.
- Sampling method: duplicate samples of new solutions were collected from freshly prepared solutions, duplicate samples of the old solutions were collected from a composite of remaining replicate test chambers.
- Sample storage conditions before analysis: Samples were collected in plastic scintillation vials and were analyzed as soon as possible without storage.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: Stirring of primary stock (2000 mg a.i./L) with an electric stainless steel top-down mixer until all the test substance was dissolved. Dilution of primary stock
with dilution water to obtain lower concentrations.
- Controls: Blank test medium
- Evidence of undissolved material: All solutions appeared clear and colorless.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Cladoceran; Water flea
- Source: Cultures maintained by the test laboratory with known history
- Age at study initiation: < 24 hours, from parental daphnids of more than two weeks old, which were observed to have no neonates present less than 24 hours prior to test initiation
- Culturing: Adult daphnids were cultured in water from the same source and at approximately the same temperature as used during the test. Adult daphnids in the cultures were held for at least 15 days prior to collection of the juveniles for testing. The adults showed no signs of disease or stress during the holding period. During the 14-day period preceding the test, water temperatures ranged from 19.8 to 20.1°C. The pH of the water ranged from 8.1 to 8.3, and dissolved oxygen ranged from 8.3 to 8.6 mg/L. Daphnids in the cultures were fed a mixture of yeast, Cerophyll®, and trout chow, as well as a suspension of the freshwater green alga, Selenastrum capricornutum.
FEEDING DURING TEST
- Food type: mixture of yeast, Cerophyll®, and trout chow, as well as a suspension of the freshwater green alga, Selenastrum capricornutum
- Frequency: once daily

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

21 d

Hardness:

128 - 140 mg CaCO3/L

Test temperature:

19.0 - 21.4 °C, from individual measurements during the test
18.0 - 21.0 °C, from continuous measurement during the test

pH:

7.9 - 8.7

Dissolved oxygen:

7.9 - 9.0 mg/L

Conductivity:

Negative Control: 325 - 340 μmhos/cm
1876 mg a.i./L Treatment Group: 800 - 850 μmhos/cm

Nominal and measured concentrations:

Nominal: 0 mg/L, 63 mg/L, 125 mg/L, 250 mg/L, 500 mg/L, 1000 mg/L, 2000 mg/L
Measured: < LOQ, 60 mg/L, 121 mg/L, 247 mg/L, 502 mg/L, 995 mg/L, 1876 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: 250-mL plastic beakers 200-mL fill volume, depth ca. 5 cm
- Aeration: dilution water aerated prior to filling.
- Renewal rate of test solution: 3x per week, every second day except every third on days 2, 9, and 16.
- No. of organisms per vessel: One
- No. of vessels per concentration (replicates): Ten
- No. of vessels per control (replicates): Ten
- Source/preparation of dilution water: 40-m deep well located at testing lab. Water was passed through a sand filter and pumped into a storage tank and aerated with spray nozzles. Water was filtered to 0.45 μm prior to use and passed through a UV sterilizer. Periodic water analysis, Attachments 1 and 2.
- Pesticides: all < LOQ
- Alkalinity: 178 - 184 mg/L as CaCO3
- pH: 8.0
- Culture medium different from test medium: No
- Intervals of water quality measurement: most recent analysis on samples collected Oct 14 and 15, 1999.
OTHER TEST CONDITIONS
- Adjustment of pH: No
- Photoperiod: 16 h:8h with 30-min transitions
- Light intensity: Colortone ® 50 fluorescent lights used for lighting, provided 357 to 512 lux at surface of a representative chamber

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :

First-generation daphnids: Observations were made daily during the test. Survival, the onset of reproduction, and clinical signs of toxicity were noted. The criteria for death included white opaque coloration, lack of movement of appendages, absence of heartbeat and lack of response to gently prodding. Immobilization was defined as lack of movement except for minor activity of the appendages. The presence of eggs in the brood pouch, aborted. eggs, males or ephippia were also recorded. At test termination, the length (measured from the apex of the head to the base of the spine) and dry weight were determined for each surviving first-generation daphnid.

Second-generation daphnids: With the onset of reproduction, neonates were counted and recorded (number of live neonates, number of dead or immobile neonates and number of aborted eggs) and the neonates removed every Monday, Wednesday and Friday during the test and at test termination. On day 14, the second-generation neonates were collected and used for a second-generation acute exposure test.
TEST CONCENTRATIONS
- Spacing factor for test concentrations: 2-fold

Reference substance (positive control):

no

Key result

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

502 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

reproduction

Details on results:

- Reproduction data summary in Table 2
- Mortality, immobility, other observations summary in Table 3
- NOEC for growth, 502 mg/L
- NOEC for survival, 995 mg/L
- Observations on body length and weight: data summary in Table 4
- Mortality of control: 10% mortality, within guideline criteria
- Second generation daphnids at day 14 (two replicates/ concentration with 10 daphnids per replicate) were collected for a 48-hr acute toxicity evaluation. At all concentrations, (1876 mg/L excluded as there were insufficient progeny to evaluate), no immobilization or mortality were observed, and all organisms appeared normal at 2, 24 and 48 hours.

Reported statistics and error estimates:

Statistical analyses were performed on survival of first-generation daphnids, the number of live young and the length and dry weight of the surviving first-generation daphnids. Survival data were analyzed using Fisher’s exact test. Treatment groups with significant survival effects were excluded from the analyses of reproduction and growth. Reproduction and growth (length and dry weight) data were evaluated for
normality and homogeneity of variance using the chi-square test and Bartlett’s test, respectively. If the data met the assumptions of normality and homogeneity, the Bonferroni t-test was used to identify treatment
groups that were statistically reduced in comparison to the negative control (p ≤ 0.05). If the data failed the assumptions of normality or homogeneity, transformations were applied to the data in an attempt to correct the condition. If transformations failed, Wilcoxon's rank sum test with the Bonferroni adjustment was used to evaluate the data (p ≤ 0.05). All statistical tests were performed on a personal computer using TOXSTAT statistical software.

Table 2, Summary of Reproduction of Surviving First-Generation Daphnids

Mean Measured Test Concentration (mg a.i./L)	First Day of Reproduction	Number of Surviving Adults	Mean Number of Live Young Per Surviving Adult ± Std. Dev.
Negative control	8	9	86 ± 27
60	8	10	173 ± 34
121	8	10	149 ± 47
247	8	10	167 ± 30
502	8	10	89 ± 26
995	8	7	43 ± 28*
1876¹	11	2	14 ± 14²

¹This treatment was excluded from statistical analyses of reproduction due to a statistically significant survival effect.

²Three dead or immobile neonates were also observed at this concentration. No dead neonates were observated at any other concentration, and no aborted eggs were found at any concentration.

* Statistically significant difference (p < 0.05) relative to negative control (Bonferroni t-test).

Table 3, Summary of Cumulative Percent Mortality, Immobility and Observations of First-Generation Daphnids

Mean Measured Test Concentration (mg a.i./L)	Number exposed	Day 7 Percent Dead	Day 7 Percent Immobile	Day 7 Obs¹	Day 14 Percent Dead	Day 14 Percent Immobile	Day 14 Obs	Day 21 Percent Dead	Day 21 Percent Immobile	Day 21 Obs	Percent survival
Negative Control	10	0	0	10 AN	0	0	10 AN	10	0	8 AN, 1 D	90
60	10	0	0	10 AN	0	0	10 AN	0	0	10 AN	100
121	10	0	0	10 AN	0	0	10 AN	0	0	10 AN	100
247	10	0	0	10 AN	0	0	10 AN	0	0	10 AN	100
502	10	0	0	10 AN	0	0	10 AN	0	0	10 AN	100
995	10	0	0	6 AN, 4 D	30	0	5 AN, 1 D, 1 D,G	30	0	6 AN, 1 D	70
1876	10	20	0	8 G	80	0	2 G	80*	0	2 D,G	20

¹ Observed effects: AN = appear normal; G = appears smaller; D = discoloration

* Indicates a significant difference from the control on Day 21 user Fisher's exact test (p≤0.05)

Table 4, Summary of Length and Dry Weight of Surviving First-Generation Daphnids

Mean Measured Test Concentration (mg a.i./L)	Number of Surviving Adults	Total Length (mm) Mean ± Std. Dev.	Dry Weight (mg) Mean± Std. Dev.
Negative control	9	4.18 ± 0.182	0.80 ± 0.29
60	10	4.89 ± 0.111	1.22 ± 0.31
121	10	4.78 ± 0.207	1.21 ± 0.34
247	10	4.77 ± 0.206	0.96 ± 0.16
502	10	4.26 ± 0.480	0.88 ± 0.16
995	7	3.69* ± 0.352	0.51 ± 0.16
1876¹	2	2.68 ± 0.106	0.10 ± 0.0

¹This treatment was excluded from the statistical analyses of growth due to a statistically significant survival effect.

*Indicates a significant difference from the negative control using Wilcoxon's rank sum test (p≤0.05).

Validity criteria fulfilled:

yes

Remarks:

The validity criteria of OECD TG 211 were met. 1) Mortality of the parent animals in the controls did not exceed 20% at the end of the test. 2) The mean number of living offspring from the parents in the controls was ≥ 60.

Conclusions:

The 21-day NOEC (reproduction) for PFBSK+ to Daphnia magna was found to be 502 mg/L (OECD TG 211).

Executive summary:

The chronic toxicity of PFBSK+ to Daphnia magna was measured with a semi-static method according to OPPTS 850.1300, OECD TG211 and ASTM Standard E 1193-96. Daphnid neonates were exposed to measured concentrations of <LOQ, 60, 121, 247, 502, 995, or 1876 mg/L with periodic renewal of test medium. The 21-day NOEC for reproduction was 502 mg/L.

This study was conducted according to internationally accepted test guidelines and conducted in accord with GLP criteria. It is reliable without restriction and suitable for Risk Assessment, Classification and Labeling, and PBT Analysis.

Description of key information

The 21-day NOEC for reproduction with PFBSK+ to Daphnia magna was determined to be 502 mg/L in a study conducted according to OECD TG 211.

Additional information

A single key study examining the chronic toxicity of PFBSK+ to Daphnia magna was carried out in 2001 using a semi-static method according to OPPTS 850.1300, OECD TG 211 and ASTM Standard E 1193-96. This study was conducted according to internationally accepted test guidelines and conducted in accord with GLP criteria, and is considered reliable without restriction.