Sodium dodecylbenzenesulfonate

Biological effects monitoring

Administrative data

Endpoint:

biological effects monitoring

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2002

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

An integrated model stream ecosystem fate and effects study of a C12LAS homologue, with a high content (35.7%) of its most hydrophobic and toxic 2-phenyl isomer, was performed in the summer and fall of 1996 in Procter and Gamble’s Experimental Stream facility. The study addressed responses of periphytic microbes, immature benthic fauna including abundance and drift, and emergence of adult insects in a 56-day exposure.

GLP compliance:

not specified

Type of study / information:

Type of test:out-door experimental streams.

Test material

Test material information

Constituent 1

Reference substance name:

Sodium dodecylbenzenesulfonate

EC Number:

246-680-4

EC Name:

Sodium dodecylbenzenesulfonate

Cas Number:

25155-30-0

Molecular formula:

C18H29NaO3S

IUPAC Name:

sodium dodecylbenzenesulfonate

Test material form:

solid: compact

Details on test material:

Dodecyl linear alkylbenzene sulfonate (C12LAS) (CAS# 25155-30-0)

Results and discussion

Any other information on results incl. tables

Microbial heterotrophs acclimated to C12LAS exposure quickly (14 days) and biodegraded C12LAS at all concentrations. Blue-green algae responded by increasing in abundance with increasing C12LAS concentration. Invertebrates responded by increased drift and reduced benthic abundances at concentrations exceeding 293 μg/LL. Emergence at 927 μg/L also declined relative to the control. Adverse responses for mayflies and chironomids were indicated using univariant statistical techniques. Multivariant techniques indicated these taxa plus molluscs, aquatic worms, caddisflies, and stoneflies were impaired at some concentrations. Bioavailability of C12LAS was investigated in streams as a function of the total suspended solids load in the water column driven by local weather and watershed patterns. A continuous bioavailability model indicated exposure was reduced by an average of 8.5 ± 8.9%. A model ecosystem NOEC (no-observed-effect-concentration) was concluded to be 293 μg/L based on measured water column exposure and adjusted to 268 μg/LL by the bioavailability model. A summary of selected population and community responses at 8 weeks from the current study is shown in the table below.

Community/Measure	Dose Response	Temporal	NOEC (µg/L)
Heterotrophic microbial Biomass (total lipid phosphate/mm^2) Amino acid uptake (^3H dpm/mm^2/min) Phospholipid fatty acid (PLFA) distr. Surfactant mineralization (% CO2)	NS NS	Shift at >293 µg/L Acclimation at all conc.
Autotrophic microbial Bicarbonate uptake (^14C dpm/mm^2/min) Algal density (cells/mm^2) Algal biovolume (µm^3/mm^2) Blue-green algal density (cells/mm^2) Green algal density (cells/mm^2) Diatom algal density (cells/mm^2) Algal richness Dominant taxa (cells/mm^2)   Cocconeis placentula   Melosira varians   Chrococcus sp.   Nitzschia dissipata   Navicula salinarum v. intermedia   Pleurosira (= Biddulphia) laevis   Nitzschia inconspicua   Nitzschia palea   Diatoma vulgare   Gyrosigma acuminatum	+ NS NS ++ NS NS - - NS + NS NS NS ++ + -- -	+ ++ - - + ++ + -- -	927 927 927 927
Invertebrates Richness Diversity (Shannon-Weaver) Total abundance (No./m^2) Insect abundance (No./m^2) EPT abundance (No./m^2) Mayfly abundance (No./m^2) Caddisfly abundance (No./m^2) True fly abundance (No./m^2) Chironomid abundance (No./m^2) Mollusk abundance (No./m^2) Oligochaete abundance (No./m^2) Dominant populations (No./m^2)   Baetis sp. (mayfly)   Isonychia sp. (mayfly)   Stenonema sp. (mayfly)   Thienemannimyla sp. (chironomid)   Tanytarsus sp. (chironomid)   Cricotopus sp. (chironomid)   Polypedilum sp. (chironomid)   Reotanytarsus sp. (chironomid)   Naididae (aquatic worm)	NS NS -- NS - NS NS NS NS NS -- b --- NS --- ++ + + NS NS	-- - -- --- --- ++ + +	293 927 293 927 293

a Plus (+) and minus (-) signs indicate whether the response significantly increased or decreased from the control condition (± = 0.05). The strength to the response was graded as slight (+/-), moderate (++/--), or great (+++/---) based on statistical analyses.   NS indicates not significant. ^bTaxon too low in abundance, emerged.

Applicant's summary and conclusion

Conclusions:

A model ecosystem NOEC (no-observed-effect-concentration) was concluded to be 293 μg/L based on measured water column exposure and adjusted to 268 μg/L by the bioavailability model.

Executive summary:

An integrated model stream ecosystem fate and effects study of a C12LAS homologue, with a high content (35.7%) of its most hydrophobic and toxic 2-phenyl isomer, was performed in the summer and fall of 1996 in Procter and Gambles Experimental Stream facility. The study addressed responses of periphytic microbes, immature benthic fauna including abundance and drift, and emergence of adult insects in a 56-day exposure. A model ecosystem NOEC (no-observed-effect-concentration) was concluded to be 293 microgram/L based on measured water column exposure and adjusted to 268 microgram/L by the bioavailability model.