Benzenesulfonic acid, 4-C10-13-sec-alkyl derivs.

Toxicity to aquatic algae and cyanobacteria

Administrative data

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1982-08-06 To 1982-08-20

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Justification for type of information:

Category Approach; test material is reference substance LAS. LAS provides suitable read across for LAB Sulfonic Acids as both form the identical chemical species in aqueous solutions at neutral (physiological) pH, namely, the LAS ion (C10-13linear alkyl benzene-SO3-) and would be expected to have similar eco-toxicological properties.

Data source

Reference

Reference 1

Reference Type:

study report

Title:

Unnamed

Year:

1982

Report date:

1982

Reference 2

Reference Type:

publication

Title:

Unnamed

Year:

1986

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: Payne AG, Hall RH, 1979, in Aquatic Toxicology, ASTM, STP 667, pp. 171-180; and US EPA, 1978, The Selenastrum capricornutum Printz algal assay. Deviations, reliability, and validity evaluated using the subsequent OECD 201 (2006) test guideline.

Deviations:

no

GLP compliance:

no

Remarks:

(study conducted prior to GLP)

Test material

Test material information

Constituent 1

Reference substance name:

Benzenesulfonic acid, C10-13-alkyl derivs., sodium salts

EC Number:

270-115-0

EC Name:

Benzenesulfonic acid, C10-13-alkyl derivs., sodium salts

Cas Number:

68411-30-3

Molecular formula:

Not applicable for UVCB

IUPAC Name:

sodium 4-undecylbenzenesulfonate

Constituent 2

Reference substance name:

Water

EC Number:

231-791-2

EC Name:

Water

Cas Number:

7732-18-5

Molecular formula:

H2O

IUPAC Name:

water

Details on test material:

- Name of test material: Linear Alkylbenzene Sulfonate; (C11.9 LAS); LAS Sodium Salt; (X0235.01)
- Substance type: Pure active substance
- Physical state: A white paste
- Stability under test conditions: Not available
- Storage condition of test material: Not available

Specific details on test material used for the study:

Material was tested as 30.4% active (30.4% LAS, 51.9% water and 17.7% inert)

Sampling and analysis

Analytical monitoring:

no

Test solutions

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: A primary stock solution of X0235.01 was prepared by adding a weighed amount of test material to algal growth medium, and other stock solutions were prepared by serial dilution. A growth medium control was conducted concurrently and contained no test material. All test concentrations were prepared by pipeting 1.0 milliliter (ml) of the appropriate stock solution to each test flask.
- Controls: AAP medium
- Evidence of undissolved material: No

Test organisms

Test organisms (species):

Raphidocelis subcapitata (previous names: Pseudokirchneriella subcapitata, Selenastrum capricornutum)

Details on test organisms:

TEST ORGANISM
- Common name: Green algae
- Strain: Not available
- Source: University of Texas at Austin, Austin, Texas
- Age of inoculum (at test initiation): Not available
- Method of cultivation: Not available

ACCLIMATION
- Acclimation period: Not available
- Culturing media and conditions: Same as test
- Any deformed or abnormal cells observed: Not available

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

120 h

Remarks on exposure duration:

72 hour results reported here

Post exposure observation period:

Yes (9 days)

Test conditions

Hardness:

Not available

Test temperature:

Static bioassays were conducted at 24 C (+/-1) degree C in water bath

pH:

Not available

Dissolved oxygen:

Not available

Nominal and measured concentrations:

Nominal laboratory exposure concentrations based on active ingredient were 0, 16, 32, 63, 125, 250, 500, and 1,000 mg/L.
No analytical measurements of test concentrations were taken.

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Open / closed: Not available
- Material: 125-ml flasks with 50 ml solution
- Aeration: No
- Initial cells density: 2x10(4) cells/ml
- Control end cells density: Test 1: 206x10(4);
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 3

GROWTH MEDIUM
- Standard medium used: Yes, AAP nutrient medium

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: AAP media prepared with deionized water
- Total organic carbon: Not available
- Particulate matter: Not available
- Metals: Not available
- Pesticides: Not available
- Chlorine: Not available
- Alkalinity: Not available
- Ca/mg ratio: Not available
- Conductivity: Not available
- Culture medium different from test medium: No
- Intervals of water quality measurement: Not available

OTHER TEST CONDITIONS
- Sterile test conditions: Not available
- Adjustment of pH: No
- Photoperiod: Not available
- Light intensity and quality: Approximately 2,000 lux

EFFECT PARAMETERS MEASURED
- Determination of cell concentrations: Hemacytometer
- Cell counts were made on day 0,2,3,4,5.

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 2 - Range finding study: no

Reference substance (positive control):

no

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

72 h

Dose descriptor:

other: ECr50

Effect conc.:

235 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

growth rate

Remarks on result:

other: 72-hr ECr50: 235 (34.6 - 965) mg/L

Remarks:

Data is present within the study report to allow for 72 hr EC10 and EC50 endpoint calculations with the emphasis on growth rate (as recommended by OECD 201). The 72 hr modernized endpoints are reported within this summary.

Effect concentrations 2

Duration:

96 h

Dose descriptor:

other: ECr10

Effect conc.:

13.1 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

growth rate

Remarks on result:

other: 96-hr ECr10: 13.1 (0 - 99) mg/L

Remarks:

Data is present within the study report to allow for 72 hr EC10 and EC50 endpoint calculations with the emphasis on growth rate (as recommended by OECD 201). The 72 hr modernized endpoints are reported within this summary.

Details on results:

- Exponential growth in the control: Yes, 103X at 72 hrs
- Observation of abnormalities: In all test concentrations >=1.0 mg/L, the algal cells were abnormally large and malformed. Because of this observation, algae previously exposed to 1000 mg/L were tested for their ability to recover. Their growth was similar to the growth of the control during a 9-day recovery period in test material-free medium, and the algal cells had returned to normal appearance.
- Any stimulation of growth found in any treatment:
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: No
- Effect concentrations exceeding solubility of substance in test medium: No

Any other information on results incl. tables

Effect of LAS on Selenastrum capricornutum: Cell Counts at 72 hr (study # 29101)

Nominal Conc (mg/L)	Algal cell counts (x10^4/ml)	Growth Rate	% Inhibition
0	318 (25)	1.5449
16	136 (37)	1.4586	5.59
32	138 (13)	1.2869	16.7
63	177 (34)	1.1447	25.91
125	45 (19)	0.8141	47.3
250	28 (4)	0.7504	51.43
500	24 (5)	0.7324	52.59
1000	5 (2)	0.3054	80.23

C10-13 LAS(X0235.01).

Numbers in parenthesis are standard deviation.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

In a 72 hour algae growth inhibition test, the EC10 and EC50 of LAS to Selenastrum capricornutum was 13.1 (0 – 99) and 235 (34.6 – 965) and mg/L, consecutively.

Executive summary:

In a 72 hour algal growth inhibition test, the green alga Selenastrum capricornutum was exposed to Linear Alkylbenzene Sulfonate (C11.9 LAS) in accordance with OECD 201. The nominal test concentrations were (test 1) control, 16, 32, 63, 125, 250, 500, and 1,000 mg a.i./L,.

The 72 hour EC10 and EC50, based on growth rate, are 13.1 (0–99) and 235 (34.6–965) mg/L, consecutively.

This algal growth inhibition test satisfies the guideline requirements of the OECD 201 guideline.

 

This study was conducted in accordance with USEPA OPPTS 850.5400. However data is present within the study report to allow for 72 hr EC10 and EC50 endpoint calculations with the emphasis on growth rate (as recommended by OECD 201). The 72 hr modernized endpoints are reported within this summary. These endpoints appear less conservative to those previously reported (96 hr endpoints based on cell count) due to the use of continuous growth rate versus cell count.