Sodium octane-1-sulphonate monohydrate

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

21 July 2008 - 12 August 2008

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

Study conducted in accordance with international guidelines and in accordance with GLP. All guideline criteria were met.

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

April 2004

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 850.1010 (Aquatic Invertebrate Acute Toxicity Test, Freshwater Daphnids)

Version / remarks:

1996

Deviations:

no

GLP compliance:

yes

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: Confidential
- Expiration date of the lot/batch: May 2009
- Purity test date: Not specified

RADIOLABELLING INFORMATION (if applicable)
- Radiochemical purity: N/A
- Specific activity: N/A
- Locations of the label: N/A
- Expiration date of radiochemical substance: N/A

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: Ambient conditions
- Stability under test conditions: Assumed stable
- Solubility and stability of the test substance in the solvent/vehicle: Soluble to at least 500 mg/L
- Reactivity of the test substance with the solvent/vehicle of the cell culture medium: None

TREATMENT OF TEST MATERIAL PRIOR TO TESTING
- Treatment of test material prior to testing: None
- Preliminary purification step (if any): None
- Final dilution of a dissolved solid, stock liquid or gel: 500 mg/L
- Final preparation of a solid: N/A

FORM AS APPLIED IN THE TEST (if different from that of starting material) As a liquid

TYPE OF BIOCIDE/PESTICIDE FORMULATION (if applicable) N/A

OTHER SPECIFICS: N/A

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: A primary stock solution was prepared at a nominal concentration of 500 mg/L, by mixing a calculated amount of the test item into dilution water (UV sterilised well water). The stock solution was mixed by inversion and appeared clear and colourless. Aliquots of the 500 mg/L stock solution were proportionally diluted with well water to prepare 500 mL of test solution at nominal concentrations of 65, 108, 180 and 300 mg/L, which were mixed by inversion. All solutions were clear and colourless at test initiation and termination.
- Eluate: N/A
- Differential loading:
- Controls: Negative control: dilution water, in duplicate
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): N/A
- Concentration of vehicle in test medium (stock solution and final test solution(s) or suspension(s) including control(s)): N/A
- Evidence of undissolved material (e.g. precipitate, surface film, etc.): None

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Waterflea
- Strain/clone: Not specified
- Justification for species other than prescribed by test guideline: N/A
- Source: Obtained from cultures maintained by Wildlife International Ltd, Easton, Maryland.
- Age of parental stock: Neonates obtained at less than 24 hours old, then cultured for 2 weeks prior to test initiation
- Feeding during test: None
- Food type: N/A
- Amount: N/A
- Frequency: N/A

ACCLIMATION
- Acclimation period: At least 14 days
- Acclimation conditions (same as test or not): Approx. the same as during the test
- Type and amount of food: Prior to test - a mixture of yeast, cereal grass media and trout chow (YCT) and a suspension of P. subcapitata
- Feeding frequency: Daily
- Health during acclimation (any mortality observed): Good (no signs of disease/stress/no ephippia)

QUARANTINE (wild caught) N/A

METHOD FOR PREPARATION AND COLLECTION OF EARLY INSTARS OR OTHER LIFE STAGES:
Adult daphnids were cultured in water from the same source and at the approximately same temperature as used in the test. The three adult daphnids used to supply neonates for the test were held for at least 14 days prior to collection of the juveniles for testing, and had each produced at least one previous brood. Adult daphnids in the culture had produced an average of at least three young per adult per day over the 7-day period prior to the test. At test inititiation, the juvenile daphnids (<24 hrs old) were collected form the cultures and indiscriminately transferred one or two at a time to transfer chambers until each chamber contained 10 daphnids. Each group of daphnids was then transferred to an indiscriminately assigned test chamber. All transfers were made below the water surface using wide-bore pipettes.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Remarks on exposure duration:

Guideline-recommended duration

Post exposure observation period:

Daily observations were made (approx. 5, 24 and 48 h after test initiation) for mortality, immobility and signs of toxicity.

Hardness:

138 mg/l as CaCO3

Test temperature:

20 +/- 1 °C

pH:

8.2 - 8.5

Dissolved oxygen:

=> 83% saturation

Salinity:

N/A

Conductivity:

368 µS/cm

Nominal and measured concentrations:

Nominal:
65, 108, 180, 300 and 500 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: 250 mL beakers
- Material, size, headspace, fill volume: Glass, 250 mL of test water
- Aeration: With spray nozzles
- Type of flow-through (e.g. peristaltic or proportional diluter): N/A
- Renewal rate of test solution (frequency/flow rate): N/A
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): Two
- No. of vessels per control (replicates): Two
- No. of vessels per vehicle control (replicates): N/A
- Biomass loading rate: Not specified

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Freshwater was obtained from a well (characterised as moderately-hard water) approx. 40 m deep, located on the Wildlife International Ltd (8598 Commerce Drive, Easton, Maryland, 21691 USA) site. The well water was passed through a sand filter to remove particles greater than approx. 25 µm, and pumped into a 37,800 L storage tank where the water was aerated with spray nozzles. Prior to use, the water was filtered to 0.45µm and passed through an ultraviolet sterilizer to remove fine particles and microorganisms.
- Total organic carbon: < 1 mg C/L
- Particulate matter: Not specified
- Metals: Not specified
- Pesticides: Not specified
- Chlorine: Not specified
- Alkalinity: 176 - 180 mg/L as CaCO3
- Ca/mg ratio: Not specified
- Conductivity: 355 - 360 µS/cm
- Salinity: N/A
- Culture medium different from test medium: No
- Intervals of water quality measurement: Daily

OTHER TEST CONDITIONS
- Adjustment of pH: No
- Photoperiod: 16 h light : 8 h dark (with a 30 m transition period of low light intensity between light and dark)
- Light intensity: 310 lux

EFFECT PARAMETERS MEASURED (with observation intervals if applicable): Mortality, immobility and signs of toxicity were observed daily

VEHICLE CONTROL PERFORMED: yes

RANGE-FINDING STUDY
- Test concentrations: Not specified
- Results used to determine the conditions for the definitive study: Not specified

Reference substance (positive control):

no

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

421 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

> 500 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

- Behavioural abnormalities: Two lethargic daphnids were observed in both 108 and 180 mg/L treatment groups. All surviving daphnids in the 300 mg/L and 500 mg/L test groups were lethargic at termination.
- Observations on body length and weight: Not specified
- Other biological observations: 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: None

Results with reference substance (positive control):

N/A

Reported statistics and error estimates:

48 h EC50: 421 mg/L (95% confidence interval 372 - 472 mg/L), calculated with probit analysis.

Table 1. Cumulative mortality, immobility and observations

Nominal test concentration (mg/L)	Replicate	Daphnia /replicate	5 hours			24 hours			48 hours			%Immobile and dead
			No. dead^1	No. immobile	Effects^2	No. dead^1	No. immobile	Effects^2	No. dead^1	No. immobile	Effects^2
Negative control	A	10	0	0	10 AN	0	0	10 AN	0	0	10 AN	0
	B	10	0	0	10 AN	0	0	10 AN	0	0	10 AN
65	A	10	0	0	10 AN	0	0	6 AN; 4Q,AN	0	0	10 AN	0
	B	10	0	0	8AN; 2Q,AN	0	0	6 AN; 4Q,AN	0	0	10 AN
108	A	10	0	0	10 AN	0	0	5 AN; 5Q,AN	0	0	10 AN	0
	B	10	0	0	10 AN	0	0	7 AN; 3Q,AN	0	0	8AN; 2C
180	A	10	0	0	8AN; 2Q,AN	0	0	4 AN; 6Q,AN	0	0	9 AN, 1Q,AN	0
	B	10	0	0	10 AN	0	0	5 AN; 4Q,AN; 1C	0	0	8 AN; 2Q,C
300	A	10	0	0	10 AN	0	0	6 AN; 4Q,AN	1	0	1Q,C; 8C	5
	B	10	0	0	9AN; 1Q,AN	0	0	8 AN; 2Q,AN	0	0	10C
500	A	10	0	0	10 AN	0	0	2Q,C; 8C	6	0	4C	80
	B	10	0	0	10 AN	0	0	1Q,C; 9C	10	0	-

¹Cumulative no. of dead Daphnia

²Observed effects: AN = appear normal; Q,AN = trapped at water surface but appear normal after submersion below the water’s surface; Q,C = trapped at water surface and appear lethargic after submersion below the water’s surface; C = lethargy

Table 2. Temperature, dissolved oxygen and pH of water in the test chambers

Nominal test concentration (mg/L)	Replicate	0 hours			24 hours			48 hours
		Temp (°C)^1	DO (mg/L)^2	pH	Temp (°C)^1	DO (mg/L)^2	pH	Temp (°C)^1	DO (mg/L)^2	pH
Negative control	A	19.9	8.7	8.2	19.8	8.8	8.3	19.8	8.6	8.4
	B	19.9	8.7	8.2	19.8	8.8	8.3	19.8	8.6	8.4
65	A	19.9	8.7	8.2	19.7	8.7	8.3	19.7	8.6	8.4
	B	20.0	8.7	8.2	19.8	8.7	8.3	19.7	8.6	8.5
108	A	19.8	8.7	8.2	19.8	8.5	8.3	19.7	8.5	8.4
	B	19.9	8.7	8.2	19.8	8.5	8.3	19.7	8.5	8.4
180	A	19.9	8.8	8.3	19.7	8.2	8.3	19.7	8.5	8.4
	B	20.0	8.7	8.3	19.8	8.3	8.3	19.8	8.5	8.4
300	A	20.0	8.7	8.3	19.7	7.9	8.3	19.7	8.4	8.4
	B	20.1	8.7	8.3	19.8	7.8	8.2	19.7	8.3	8.4
500	A	20.1	8.8	8.2	19.8	7.5	8.2	19.7	7.9	8.3
	B	20.2	8.8	8.2	19.8	7.5	8.2	19.7	7.8	8.3

¹Manual temperature measurements, temperature measured continuously during the test ranged from approx. 19.5 – 20°C, measured to the nearest 0.5°C.

²A dissolved oxygen concentration of 5.4 mg/L represents 60% saturation at 20°C in freshwater

Validity criteria fulfilled:

yes

Conclusions:

Under the conditions of the test, the test item was found to have a 48 h EC50 of 421 mg/L (95% CI: 372 - 472 mg/L). The 24 h EC50 was established as > 500 mg/L.

Executive summary:

A short-term toxicity test compliant with OECD Test Guideline 202 (April 2004) was performed on Daphnia magna, in order to ascertain the toxic effects of sodium-1-octane-sulphonate.

D. magna were exposed to concentrations of the test item in duplicate (65, 108, 180, 300 and 500 mg/L) over a period of 48 hours, under static conditions. Observations were made daily to assess mortality, immobility and abnormal behaviour. There was no mortality, nor immobility or abnormal behaviour in the control.

All daphnids in the 65 mg/L treatment group appeared normal throughout the test. All daphnids in the 108 mg/L and 180 mg/L treatment groups appeared normal throughout the test with the exception of two lethargic daphnid in each of treatment group at the test termination. Percentage mortality/immobility at test termination in the 300 mg/L treatment groups were 5% and 80% respectively. All surviving daphnids in the 300 mg/L and 500 mg/L test groups were lethargic at termination.

Under the conditions of the test, the test item was found to have a 48 h EC50 of 421 mg/L (95% CI: 372 - 472 mg/L). The 24 h EC50 was established as > 500 mg/L. The slope of the concentration curve was 11.212.

Description of key information

Short-term toxicity to D. magna: 48 h EC50 >100 mg/L; OECD 202; Minderhout and Krueger (2008).

Additional information

A short-term toxicity test compliant with OECD Test Guideline 202 (April 2004) was performed on Daphnia magna, in order to ascertain the toxic effects of sodium-1-octane-sulphonate.

D. magna were exposed to concentrations of the test item in duplicate (65, 108, 180, 300 and 500 mg/L) over a period of 48 hours, under static conditions. Observations were made daily to assess mortality, immobility and abnormal behaviour. There was no mortality, nor immobility or abnormal behaviour in the control.

All daphnids in the 65 mg/L treatment group appeared normal throughout the test. All daphnids in the 108 mg/L and 180 mg/L treatment groups appeared normal throughout the test with the exception of two lethargic daphnid in each of treatment group at the test termination. Percentage mortality/immobility at test termination in the 300 mg/L treatment groups were 5% and 80% respectively. All surviving daphnids in the 300 mg/L and 500 mg/L test groups were lethargic at termination.

Under the conditions of the test, the test item was found to have a 48 h EC50 of 421 mg/L (95% CI: 372 - 472 mg/L). The 24 h EC50 was established as > 500 mg/L. The slope of the concentration curve was 11.212.

It can be concluded that the 48 h EC50 for aquatic invertebrates is above the regulatory limit concentration of 100 mg/L. No hazard is therefore identified for short-term toxicity to aquatic invertebrates.