Benzenesulfonic acid, 4-C10-13-sec-alkyl derivs., compds. with triethanolamine

Toxicity to other aquatic organisms

Administrative data

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Acceptable, well-documented publication/study report which meets basic scientific principles

Data source

Reference

Reference Type:

publication

Title:

Bioavailability of sediment-sorbed and aqueous surfactants to Chironomus riparius (midge).

Author:

Pittinger, C.A., Woltering, D.M., and Masters, J.A.

Year:

1989

Bibliographic source:

Environ. Toxicol. Chem. 8:1023-1033.

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

Tests were conducted as an aqueous fraction in the presence of sediment.

GLP compliance:

not specified

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:

C16-19 H25-31 Na O3 S

IUPAC Name:

sodium 4-undecylbenzenesulfonate

Details on test material:

C11.8 LAS; 30.4% activity; mean molecular weight = 346

Sampling and analysis

Analytical monitoring:

yes

Test solutions

Vehicle:

not specified

Details on test solutions:

Natural stream sediments (71% clay, 19% fine silt, 4% medium sand, 6% fine sand) were collected from a pristine site in Rapid Creek, SD. Before testing, wet sediment was autoclaved for 40-60 minutes to reduce microbial populations and minimize initial rates of surfactant biodegradation.

Test organisms

Test organisms (species):

other: Chironomus riparius

Study design

Test type:

other: flow-through closed system

Water media type:

not specified

Limit test:

no

Total exposure duration:

24 h

Remarks on exposure duration:

average

Test conditions

Hardness:

"monitored frequently"

Test temperature:

"monitored frequently"

pH:

"monitored frequently"

Dissolved oxygen:

"monitored frequently"

Nominal and measured concentrations:

Test concentrations were control, 8, 42, 146, 319, and 993 ppm.

Details on test conditions:

LAS was added to a sediment slurry at a nominal concentration and stirred overnight, then 350 g was poured into each test chamber and allowed to settle. The organic carbon content of the test sediment was 4.2% prior to testing. A flow-through diluter system delivered test material in water to glass containers with 120-140 cm² bottom surface area each. Intact egg masses were incubated in Petri dishes containing 20-30 mL of dilution water at 22 °C until hatching commenced. Newly hatched larvae were allowed to mature 72 hours before testing. Twenty larvae were randomly distributed to each duplicate test chamber for each of five test concentrations plus the controls. Larvae were fed daily until emergence of the first adult in each chamber. Tests were continued until each midge emerged as an adult or larvae were determined to be dead.

Reference substance (positive control):

yes

Results and discussion

Effect concentrations

Effect concentrations 1

Key result

Dose descriptor:

NOEC

Effect conc.:

319 other: ppm in sediment

Basis for effect:

other: emergence

Effect concentrations 2

Dose descriptor:

LOEC

Effect conc.:

993 other: ppm in sediment

Basis for effect:

other: emergence

Details on results:

Adults typically emerged 12-14 days after hatching. Control values for adult emergence were similar to or exceeded the historical average observed in their laboratory (>90%). Percent emergence was 98, 95, 90, 90, 90, and 73 for the control, 8, 42, 146, 319, and 993 ppm concentrations, respectively. For comparison, additional flow-through studies were conducted without sediment.

Any other information on results incl. tables

Results indicate that sorption onto sediment significantly mitigates LAS bioavailability.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The NOEC for Chironomus riparius in sediment was 319 ppm, and the LOEC was 993 ppm based on emergence.

Executive summary:

LAS was added to a sediment slurry at a nominal concentration and stirred overnight, then 350 g was poured into each test chamber and allowed to settle. The organic carbon content of the test sediment was 4.2% prior to testing. A flow-through diluter system delivered test material in water to glass containers with 120-140 cm² bottom surface area each. Intact egg masses were incubated in Petri dishes containing 20-30 mL of dilution water at 22 °C until hatching commenced. Newly hatched larvae were allowed to mature 72 hours before testing. Twenty larvae were randomly distributed to each duplicate test chamber for each of five test concentrations plus the controls. Larvae were fed daily until emergence of the first adult in each chamber. Tests were continued until each midge emerged as an adult or larvae were determined to be dead.

Adults typically emerged 12-14 days after hatching. Control values for adult emergence were similar to or exceeded the historical average observed in their laboratory (>90%). Percent emergence was 98, 95, 90, 90, 90, and 73 for the control, 8, 42, 146, 319, and 993 ppm concentrations, respectively. For comparison, additional flow-through studies were conducted without sediment.

The NOEC for Chironomus riparius in sediment was 319 ppm, and the LOEC was 993 ppm based on emergence.