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Ecotoxicological information

Short-term toxicity to aquatic invertebrates

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Administrative data

Endpoint:
short-term toxicity to aquatic invertebrates
Type of information:
experimental study
Adequacy of study:
weight of evidence
Study period:
From May 20, 1988 to May 28, 1988
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Acceptable, well-documented study report which meets basic scientific principles.
Cross-referenceopen allclose all
Reason / purpose for cross-reference:
reference to same study
Reason / purpose for cross-reference:
reference to other study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1990
Report date:
1990

Materials and methods

Test guideline
Qualifier:
no guideline followed
Principles of method if other than guideline:
Mature Hyalella azeteca were exposed to the test substance at concentrations of 0, 0.63, 1.3, 2.5, 5.0 and 10 mg active ingredient/L for 192 h. The Hyalella were observed for mortality after 48, 96, 144 and 192 h. Results were analysed for the calculation LC50.
GLP compliance:
yes
Remarks:
According to EPA GLP

Test material

Constituent 1
Reference substance name:
68081-81-2
Cas Number:
68081-81-2
IUPAC Name:
68081-81-2
Constituent 2
Reference substance name:
Benzenesulfonic acid, mono-C10-16-alkyl derivs., sodium salts
EC Number:
268-356-1
EC Name:
Benzenesulfonic acid, mono-C10-16-alkyl derivs., sodium salts
IUPAC Name:
268-356-1
Constituent 3
Reference substance name:
Linear alkyl benzene sulfonate (LAS)
IUPAC Name:
Linear alkyl benzene sulfonate (LAS)
Constituent 4
Reference substance name:
C12.3 LAS
IUPAC Name:
C12.3 LAS
Details on test material:
- Name of test material: C12.3 LAS (linear alkylbenzene sulfonate) (TSIN # P2504.01)
- Substance type: Pure active substance
- Physical state: Brown liquid
- Stability under test conditions: Not reported
- Storage condition of test material: Cool dark place
- Other:
-Solubility: 1-10% in water
- Molecular weight: 326.9

Sampling and analysis

Analytical monitoring:
no

Test solutions

Vehicle:
no
Details on test solutions:
PREPARATION AND APPLICATION OF TEST SOLUTION: 20 mg/L stock solution was prepared by diluting 0.0212 g of test material in 1000 mL of distilled water. The test solutions were prepared by adding the appropriate volume of stock solution to dilution water to provide the required total solution volume. Each test solution was mixed on a magnetic stirrer for approximately 30 sec and then divided into the appropriate replicate exposure vessels.

Test organisms

Test organisms (species):
other aquatic crustacea: Hyalella azteca
Details on test organisms:
TEST ORGANISM
- Common name: Amphipod
- Strain: Not reported
- Source: Springborn Life Sciences (SLS) culture facility
- Maintenance of stock culture: The culture water was well water with dissolved oxygen (in mg/L), pH and temperature (°C) of 8.4-8.7, 7.4 and 20, respectively. The culture areas received regulated photoperiod of 16 h light and 8 h darkness. The stock cultures were fed a solution of trout chow and a chocolate food supplement once each day. A temperature controlled water bath was used to maintain the culture solution temperatures at 20 ± 2 °C.
- Age at study initiation: Mature animals were used in the study
- Weight, length at study initiation: Not reported. All animals were of same size
- Method of breeding: Not specified
- Feeding during test: Animals were not fed during the 96 h exposure period. However, animals were fed solution of trout chow and a chocolate food supplement when test was extended beyond 96 h

ACCLIMATION: Acclimation period/conditions not reported in the study

Study design

Test type:
static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
192 h
Remarks on exposure duration:
As the difference between the 48 and 96 h LC50 value exceeded a factor of two, the exposure was extended after 96 h to 144 h and then again to 192 h when an asymptotic LC50 had been reached
Post exposure observation period:
None

Test conditions

Hardness:
24-30 mg/L CaCO3 (measured by the EDTA titrimetric method)
Test temperature:
21-22 °C (measured with Brooklyn alcohol thermometer)
pH:
7.1, ranged 6.7- 8.5 (measured by La Motte pH meter and combination electrode)
Dissolved oxygen:
Ranged 3.0-8.8 mg/L (measured with a YSI Model #57 dissolved oxygen meter and probe)
Nominal and measured concentrations:
Nominal test concentrations were: 0, 0.63, 1.3, 2.5, 5.0 and 10 mg active ingredient/L
Details on test conditions:
TEST SYSTEM
- Test vessel: Glass beaker
- Type: Closed. (All beakers were covered with clear plastic wrap)
- Material, size, headspace, fill volume: 100 mL glass beaker containing 80 mL of exposure solution. The exposure solution was 4.6 cm deep, with a surface area of 1.6 cm2.
- Aeration: Yes. Aeration was initiated after Day 6 of the study to maintain appropriate dissolved oxygen levels
- No. of organisms per vessel: 1
- No. of vessels per concentration (replicates): 10
- No. of vessels per control (replicates): 10
- Biomass loading rate: 1 animal/80 mL test solution

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Well water obtained from 100 m deep bedrock well
- Total organic carbon: Not reported
- Particulate matter: Not reported
- Metals: Not reported
- Pesticides: Not reported
- Chlorine: Not reported
- Total alkalinity: 22-24 mg/L as CaCO3 (potentiometric titration to an endpoint of pH 4.5)
- Ca/mg ratio: Not reported
- Specific conductivity: 90 - 110 µmhos/cm (measured by yellow springs Instrument Company Model #33 salinity-conductivity-temperature meter and probe)
- Culture medium different from test medium: No
- Intervals of water quality measurement: Observation of physical and biological characteristics of each replicate test solution were recorded at least every 48 h during the exposure period. The pH, dissolved oxygen concentration and temperature were measured at 0, 24, 48, 72, 96, 120, 144, 160 and 192 h in the vessel of the two highest treatment levels and the control.

OTHER TEST CONDITIONS
- Adjustment of pH: Not reported
- Photoperiod: 16 h of light and 8 h of darkness
- Light intensity: 200 footcandles (Sylvania GRO-LUX® and Cool White® fluorescent lights). Light intensity was measured with General Electric type 214 light meter

EFFECT PARAMETERS MEASURED: Hyalella were observed for mortality after 48, 96, 144 and 192 h.

NEGATIVE CONTROL PERFORMED: Yes (received only dilution water)

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 2
- Range finding study: Prior to the initiation of each definitive exposure, preliminary range-finding test were conducted and data obtained from preliminary exposure was used to select the definitive test concentration
- Test concentrations: Not reported
- Results used to determine the conditions for the definitive study: Yes
Reference substance (positive control):
no

Results and discussion

Effect concentrationsopen allclose all
Duration:
48 h
Dose descriptor:
LC50
Effect conc.:
7.6 mg/L
Nominal / measured:
nominal
Conc. based on:
act. ingr.
Basis for effect:
mortality
Remarks on result:
other: 4.9-21
Key result
Duration:
96 h
Dose descriptor:
LC50
Effect conc.:
3.5 mg/L
Nominal / measured:
nominal
Conc. based on:
act. ingr.
Basis for effect:
mortality
Remarks on result:
other: 2.4 - 5.3
Duration:
144 h
Dose descriptor:
LC50
Effect conc.:
1.1 mg/L
Nominal / measured:
nominal
Conc. based on:
act. ingr.
Basis for effect:
mortality
Remarks on result:
other: 0.23 - 1.9
Duration:
192 h
Dose descriptor:
LC50
Effect conc.:
0.96 mg/L
Nominal / measured:
nominal
Conc. based on:
act. ingr.
Basis for effect:
mortality
Remarks on result:
other: 0.29 - 1.6
Details on results:
- Behavioural abnormalities: Several of the surviving amphipods exhibited lethargic behavior. See 'Table 1' in the section 'Any other information on results'.
- Observations on body length and weight: Not reported
- Other biological observations: None
- Mortality: See Table 1 below.
- Other adverse effects control: Not reported
- Abnormal responses: Not reported
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: No visible signs of undissolved test material (e.g. precipitate, film on the solution¿s surface) were observed in any exposure solution. Water quality parameters measured during each test were generally unaffected by the concentration of test material tested and remained within acceptable ranges for the survival of the exposed organisms.
- Effect concentrations exceeding solubility of substance in test medium: No
Reported statistics and error estimates:
If at least one test concentration caused mortality of greater than or equal to 50% of the test population, then a computer program modified from the program of C. Stephan was used to calculate the LC50 values and 95% confidence intervals. Three statistical methods were available in the computer program: moving average angle analysis, probit analysis, and nonlinear interpolation with 95% confidence intervals calculated by binomial probability. See study report for more details on statistical methods.

All LC50s for Hyalella were estimated by probit analysis (48 hr, 96 hr, 144 hr, 196 hr).

Any other information on results incl. tables

Table 1: Cumulative percent mortalities and observations made during the 96 h static exposure of amphipods to linear alkylbenzene sulfonate (Hyalella azetec) (study # 34845)

Nominal concentration (mg active ingredient/L) Percent Mortalities (%)
48 h (mean) 96 h (mean) 144 h (mean) 192 h (mean)
Control 0 0 20ef 30
0.63 0 10b 60be 60
1.3 0 0d 30ef 30
2.5 20 30b 60de 70
5 30b 60b 90de 100
10 60c 100 100 100

aValue represents the mean percent of all replicate vessesls; (N=10)

bTwo surviving amphipods exhibited lethargic behavior

cAll surviving amphipods exhibited lethargic behavior

dOne surviving amphipod exhibited lethargic behavior

eUneaten food was observed in the bottom of the beakers and caught on the amphipods

fSeveral of the surviving amphipods exhibited lethargic behavior

Results were based on 92.9% active ingredient Test material was C12.3 LAS.

Applicant's summary and conclusion

Validity criteria fulfilled:
not applicable
Conclusions:
The 96 hr LC50 of C12.3 LAS (linear alkylbenzene sulfonate) to amphipods (Hyalella azetec) was 3.5 mg active ingredient/L, based on nominal concentration of test substance.
Executive summary:

The 96 hr LC50 of linear alkylbenzene sulfonate (C12.3 LAS) to Hyalella azetec was determined under static conditions. The nominal test concentrations were 0, 0.63, 1.3, 2.5, 5.0 and 10 mg active ingredient/L. The mortality of amphipods was determined at 48, 96, 144 and 192 h.

The 96 hr LC50 of linear alkylbenzene sulfonate to amphipods (Hyalella azetec) was 3.5 mg/L (2.4 -5.3). LC50s were estimated for the following time points: 48 hr       7.6 mg/L       (4.9 -21.0) 96 hr       3.5 mg/L       (2.4 -5.3) 144 hr       1.1 mg/L       (0.23 -1.9) 196 hr       0.96 mg/L       (0.29 -1.6)

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