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Long-term toxicity to aquatic invertebrates

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Endpoint:
long-term toxicity to aquatic invertebrates
Type of information:
experimental study
Adequacy of study:
supporting study
Study period:
1976-04 to 1977-02
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
comparable to guideline study
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 211 (Daphnia magna Reproduction Test)
Deviations:
no
GLP compliance:
no
Remarks:
Study pre-dates GLP
Analytical monitoring:
yes
Details on sampling:
- Concentrations: all concentrations
- Sampling method: Samples were taken from test vessels on day 0, and every 3-5 days through out the 21-day test.
- Sample storage conditions before analysis: Preserved with 1% formaldehyde and stored at 5 C until analysis.
Vehicle:
no
Details on test solutions:
PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: Direct dilution of the appropriate amount of test substance into blended well water
- Controls: Blended well water
- Evidence of undissolved material: no
Test organisms (species):
Daphnia magna
Details on test organisms:
TEST ORGANISM
- Common name: Water flea
- Strain/clone: N/A
- Source: In-house culture
- Age of parental stock: not specified
- Age of test organisms: <12 h old at beginning of test
- Feeding during test: yes
- Food type: ground trout chow/alfalfa mixture, 1000 mg/L
- Amount: 5 mg/L
- Frequency: Each diluter cycle

ACCLIMATION
- Acclimation period: Not specified
- Acclimation conditions (same as test or not): N/A
- Type and amount of food: N/A
- Feeding frequency: N/A
- Health during acclimation (any mortality observed): N/A

METHOD FOR PREPARATION AND COLLECTION OF EARLY INSTARS OR OTHER LIFE STAGES: Young were manually siphoned from existing culture units.
Test type:
flow-through
Water media type:
freshwater
Limit test:
no
Total exposure duration:
21 d
Hardness:
120 +/- 18 mg/L CaCO3
Test temperature:
21 +/- 1 C
pH:
7.5 +/- 0.2 SU
Dissolved oxygen:
8.9 +/- 0.4 mg/L
Salinity:
N/A
Nominal and measured concentrations:
The nominal test concentrations were not specified in the study report. Mean Measured concentrations were 0, 0.32, 0.59, 1.18, 2.52, and 4.85 mg/L C11.8 LAS (active ingredient).
Details on test conditions:
TEST SYSTEM
- Test vessel:
- Type: open
- Material: 1 liter glass beakers, 1 L test solution
- Aeration: N/A (test was flow-thru)
- Type of flow-through: Mount and Brungs proportional diluter, with modifications
- Renewal rate of test solution: 125 ml per 20 min cycle, or one chamber volume every 2.5 hr.
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4
- Biomass loading rate: 5 daphnids/L

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Blended well water (a mixture of well water and deionized water)
- Total organic carbon: N/A
- Particulate matter: N/A
- Metals: N/A
- Pesticides: N/A
- Chlorine: N/A
- Alkalinity: N/A
- Ca/mg ratio: N/A
- Conductivity: N/A
- Salinity: N/A
- Culture medium different from test medium: No
- Intervals of water quality measurement: Daily

OTHER TEST CONDITIONS
- Adjustment of pH: N/A
- Photoperiod: N/A
- Light intensity: N/A

EFFECT PARAMETERS MEASURED: Mortality, 24 hr, 96 hr, 7 days, then daily to end of test. Reproduction, daily beginning day 7 or 8 to end of test.

RANGE-FINDING STUDY: no
Reference substance (positive control):
no
Key result
Duration:
21 d
Dose descriptor:
NOEC
Effect conc.:
1.35 mg/L
Basis for effect:
other: Parent survival and reproduction
Remarks on result:
other: Normalized to carbon chain length 11.6
Duration:
21 d
Dose descriptor:
NOEC
Effect conc.:
1.18 mg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
act. ingr.
Basis for effect:
other: Parent (F0) Survival and reproduction (Total # young in 21 days; and Mean Brood Size)
Duration:
21 d
Dose descriptor:
EC50
Effect conc.:
1.72 mg/L
Basis for effect:
other: Total young production
Remarks on result:
other: Normalized to carbon chain length 11.6
Duration:
21 d
Dose descriptor:
EC50
Effect conc.:
1.5 mg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
act. ingr.
Basis for effect:
other: Total young production
Remarks on result:
other: 95% CL 0.75-3.33 mg/L
Duration:
21 d
Dose descriptor:
LC50
Effect conc.:
1.91 mg/L
Basis for effect:
mortality
Remarks on result:
other: Normalized to carbon chain length 11.6
Duration:
21 d
Dose descriptor:
LC50
Effect conc.:
1.67 mg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
act. ingr.
Basis for effect:
mortality
Remarks on result:
other: 95% CL 1.28-2.18 mg/L
Duration:
21 d
Dose descriptor:
EC50
Effect conc.:
2.63 mg/L
Basis for effect:
other: average brood size
Remarks on result:
other: Normalized to carbon chain length 11.6
Duration:
21 d
Dose descriptor:
EC50
Effect conc.:
2.3 mg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
act. ingr.
Basis for effect:
other: Average brood size
Remarks on result:
other: 95% CL 1.62-3.55 mg/L
Duration:
21 d
Dose descriptor:
EC50
Effect conc.:
2.65 mg/L
Basis for effect:
other: Percentage of days reporduction occurred
Remarks on result:
other: Normalized to carbon chain length 11.6
Duration:
21 d
Dose descriptor:
EC50
Effect conc.:
2.31 mg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
act. ingr.
Basis for effect:
other: Percentage of days reproduction occurred
Remarks on result:
other: 95% CL 0.30-4.18 mg/L
Duration:
4 d
Dose descriptor:
LC50
Effect conc.:
4.51 mg/L
Basis for effect:
mortality
Remarks on result:
other: Normalized to carbon chain length 11.6
Duration:
96 h
Dose descriptor:
LC50
Effect conc.:
3.94 mg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
act. ingr.
Basis for effect:
mortality
Remarks on result:
other: 95% CL 2.87-6.83 mg/L
Details on results:
These experimental results were normalized to reflect a C11.6 chain length using a highly localized LAS-specific QSAR (Belanger et al, 2016). Toxicity normalization was performed using this basic fo rmula:

ChVc11.6norm = ChVx * (ChVc11.6pred / ChVxpred)

Where ChV is any chronic endpoint result; such as NOEC, LOEC, EC10, etc., ChVc11.6norm is the normalized ChV for the test material,
ChVx is the experimental ChV for the test material,
ChVc11.6pred is the QSAR predicted ChV for the target material with a chain length of C11.6, ChVxpred is the QSAR predicted ChV for a material with the same chain length as the test
material.

A QMRF is available on the QSAR (Belanger et al, 2016) used to provide the predicted results for normalization. More details on this approach are available in the endpoint summary.

- Mortality of parent animals: Controls, 10%
- No. of offspring produced per Control: 39
- Body length and weight of parent animals: N/A
- Type and number of morphological abnormalities: N/A
- Type and number of behavioural abnormalities: N/A
- Number of males and females (parental): N/A
- Time to first brood release or time to hatch- 7 or 8 days
- Egg development time: N/A
- Brood size: Control, 8.0 (mean)
- Time to sexual maturity: N/A
- Type and magnitude of biochemical changes: N/A
- Other biological observations: N/A
- Effect concentrations exceeding solubility of substance in test medium: no
Reported statistics and error estimates:
All results were calculated with a computerized probit analysis program after Finney (1964, 1971). Survival data for 96 hr and 21 days was used to calculate LC50 values and confidence limits. All results were calculated based on mean measured concentrations of test material.

Chronic Toxicity of C11.8 LAS to Daphnia magna (study # 20710)

Mean Measured Test Conc (mg/L)

% Survival

Total Young Produced

Mean Brood Size

% of Days that Reproduction Occurred

0

90

786

8.0

82

0.32

85

1445

11.7

96

0.59

85

1131

9.7

90

1.18

75

1036

10.7

86

2.52

40

477

7.9

71

4.85

0

0

0

0

N=20 organisms at beginning of test (4 replicates of 5 organisms each).

LAS = linear alkylbenzene sulfonate.

Validity criteria fulfilled:
yes
Conclusions:
The 21 day NOEC of C11.8 LAS to Daphnia magna was 1.35 mg/L, based on survival and reproduction. The 21 day LC50 was 1.91 mg/L. Results are based on the mean measured concentration of the active ingredient. These results are normalized to reflect the toxicity of an LAS with a carbon chain length of 11.6. The non-normalized results are 1.18 mg/L for the NOEC, and 1.67 mg/L for the LC50.
Executive summary:

The long-term toxicity of C11.8 LAS (linear alkylbenzene sulfonate)) was evaluated in a 21 day survival and reproduction test with Daphnia magna, following the OECD 211 guideline. Four replicates per concentration, 5 organisms per replicate, were tested in a flow-through system (a modified Mount and Brungs proportional diluter). Mean measured concentrations were: Control, 0.32, 0.59, 1.18, 2.52, and 4.85 mg/L active ingredient (C11.8 LAS).

 

Survival was monitored at 24 hr, 96 hr, 7 days and daily thereafter. Reproduction was monitored beginning with the production of the first brood on day 7 or 8, and daily thereafter. LC50s and EC50s were calculated by probit analysis. Results are based on the mean measured concentration of the active ingredient.

 

The 21-day NOEC was 1.18 mg/L, based on both survival and reproduction. The 21-day LC50 was 1.67 mg/L (95% CL 1.28 -2.18 mg/L). The 21-day EC50s, based on total young production, average brood size, and % days reproduction occurred, were 1.50, 2.30, and 2.31 mg/L, respectively.


Endpoint:
long-term toxicity to aquatic invertebrates
Type of information:
experimental study
Adequacy of study:
supporting study
Study period:
From Mar. 07, 1983 to Aug. 12, 1983
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Acceptable, well-documented study report which meets basic scientific principles
Reason / purpose:
reference to same study
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 211 (Daphnia magna Reproduction Test)
Deviations:
no
GLP compliance:
no
Analytical monitoring:
no
Vehicle:
no
Details on test solutions:
PREPARATION AND APPLICATION OF TEST SOLUTION:
- Test solutions were prepared by adding the test material from a stock solution, prepared in deionized water, to the test water.
Test organisms (species):
Ceriodaphnia sp.
Details on test organisms:
TEST ORGANISM
- Common name: Water flea
- Strain/clone: Not reported
- Justification for species other than prescribed by test guideline: The standard chronic invert test uses Daphnia magna, and is 21 days. Ceriodaphnia, another water flea, is an alternate to Daphnia magna. The Ceriodaphnia chronic test is 7 days. Ceriodaphnia is similar in sensitivity to Daphnia.
- Source: Not reported
- Age of parental stock: Neonate Ceriodaphnia (≤24 h old)
- Feeding during test: Yes
- Food type: Diet of baker's yeast, or a mixture of algae, trout chow and alfalfa.
- Amount: Feeding amount was same as of stock cultures
- Frequency: Feeding frequency was same as of stock cultures

ACCLIMATION
- Acclimation period: Acclimated to test conditions (water/diet) combination for at least two generations.
- Acclimation conditions: Same as test
- Type and amount of food: Type of food was same as used during test
- Feeding frequency: Not reported
- Health during acclimation (any mortality observed): Not reported
Test type:
semi-static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
7 d
Hardness:
Average total hardness: 110 ± 9 mg/L as CaCO3
Test temperature:
Temperature was same as described for stock cultures
pH:
Average pH: 7.4 ± 0.2
Dissolved oxygen:
Average dissolved oxygen: 9.7 ± 0.8 mg/L
Nominal and measured concentrations:
Nominal: 0, 0.5, 1, 2, 3.5, 5, 7 mg a.i./L
Details on test conditions:
TEST SYSTEM
Test vessel: 50 mL glass beaker
- Type: Open
- Fill volume: 50 mL glass beaker containing 30 mL of test solution
- Aeration: No (static-renewal test)
- Renewal rate of test solution: all test chambers were renewed with fresh test solution three times during the test procedure (on Day 2, 4 and 6)
- No. of organisms per vessel: One
- No. of vessels per concentration (replicates): 10
- No. of vessels per control (replicates): 10
- Biomass loading rate: 1 daphnid/30 mL test solution

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Ohio River water
- Total suspended solids: 87 mg/L
- Total organic carbon: Not reported
- Particulate matter: Not reported
- Metals: Not reported
- Pesticides: Not reported
- Chlorine: Not reported
- Alkalinity: Not reported
- Ca/mg ratio: Not reported
- Conductivity: Not reported
- Culture medium different from test medium: No
- Intervals of water quality measurement: pH and dissolved oxygen content of fresh and used test solutions were routinely monitored.

OTHER TEST CONDITIONS
- Adjustment of pH: No
- Photoperiod: Same as of stock cultures
- Light intensity: Same as of stock cultures

EFFECT PARAMETERS MEASURED: Percent mortality, total reproduction, first day of reproduction, reproduction/individual, # of broods, brood size. All parameters were measured daily.

RANGE-FINDING STUDY: No
Key result
Duration:
7 d
Dose descriptor:
NOEC
Effect conc.:
0.59 mg/L
Basis for effect:
reproduction
Remarks on result:
other: Normalized to carbon chain length 11.6
Key result
Duration:
7 d
Dose descriptor:
NOEC
Effect conc.:
0.5 mg/L
Nominal / measured:
nominal
Conc. based on:
act. ingr.
Basis for effect:
reproduction
Remarks:
brood size
Remarks on result:
other: Ceriodaphnia were fed the yeast diet
Key result
Duration:
7 d
Dose descriptor:
NOEC
Effect conc.:
5.88 mg/L
Basis for effect:
mortality
Remarks on result:
other: Normalized to carbon chain length 11.6
Key result
Duration:
7 d
Dose descriptor:
NOEC
Effect conc.:
5 mg/L
Nominal / measured:
nominal
Conc. based on:
act. ingr.
Basis for effect:
other: mortality and reproduction
Remarks on result:
other: Ceriodaphnia were fed the algae-trout chow diet
Key result
Duration:
7 d
Dose descriptor:
LOEC
Effect conc.:
1.18 mg/L
Basis for effect:
reproduction
Remarks on result:
other: Normalized to carbon chain length 11.6
Duration:
7 d
Dose descriptor:
LOEC
Effect conc.:
1 mg/L
Nominal / measured:
nominal
Conc. based on:
act. ingr.
Basis for effect:
reproduction
Remarks on result:
other: Ceriodaphnia were fed the yeast diet
Duration:
7 d
Dose descriptor:
LOEC
Effect conc.:
8.24 mg/L
Basis for effect:
mortality
Remarks on result:
other: Normalized to carbon chain length 11.6
Duration:
7 d
Dose descriptor:
LOEC
Effect conc.:
7 mg/L
Nominal / measured:
nominal
Conc. based on:
act. ingr.
Basis for effect:
other: mortality and reproduction
Remarks on result:
other: Ceriodaphnia were fed the algae-trout chow diet
Duration:
7 d
Dose descriptor:
LC50
Effect conc.:
6.28 mg/L
Basis for effect:
mortality
Remarks on result:
other: Normalized to carbon chain length 11.6
Duration:
7 d
Dose descriptor:
LC50
Effect conc.:
5.34 mg/L
Nominal / measured:
nominal
Conc. based on:
act. ingr.
Basis for effect:
mortality
Remarks on result:
other: CL=4.3-7.6; Ceriodaphnia were fed the yeast diet
Duration:
7 d
Dose descriptor:
LC50
Effect conc.:
> 5 - < 7 mg/L
Nominal / measured:
nominal
Conc. based on:
act. ingr.
Basis for effect:
mortality
Remarks on result:
other: Ceriodaphnia were fed the algae-trout chow diet
Details on results:
These experimental results were normalized to reflect a C11.6 chain length using a highly localized LAS-specific QSAR (Belanger et al, 2016). Toxicity normalization was performed using this basic fo rmula:

ChVc11.6norm = ChVx * (ChVc11.6pred / ChVxpred)

Where ChV is any chronic endpoint result; such as NOEC, LOEC, EC10, etc., ChVc11.6norm is the normalized ChV for the test material,
ChVx is the experimental ChV for the test material,
ChVc11.6pred is the QSAR predicted ChV for the target material with a chain length of C11.6, ChVxpred is the QSAR predicted ChV for a material with the same chain length as the test
material.

A QMRF is available on the QSAR (Belanger et al, 2016) used to provide the predicted results for normalization. More details on this approach are available in the endpoint summary.

- Mortality of parent animals: For details on mortality, refer to ‘Table 1’ and ‘Table 2’ under 'Any other information on results incl. tables' section.
- No. of offspring produced per day per female: See Tables 1,2 below
- Type and number of morphological abnormalities: Not reported
- Type and number of behavioural abnormalities: Not reported
- Number of males and females (parental): Not reported
- Time to first brood release or time to hatch: 4-5 days in control
- Egg development time: Not reported
- Brood size: Please refer Table 1 and 2 under 'Any other information on results incl. table' section
- Time to sexual maturity: Not reported
- Type and magnitude of biochemical changes: Not reported
- Effect concentrations exceeding solubility of substance in test medium: No
Results with reference substance (positive control):
N/A
Reported statistics and error estimates:
- Probit analysis was used to calculate LC50 values and associated 95 % confidence interval.
- Chi-square techniques was used for survival analysis.
- ANOVA technique was used for reproduction parameters.

Table 1. Chronic toxicity of LAS to Ceriodaphnia Sp.: Ohio River Water, yeast Diet (Study # 29717)

Concentration nTotal reproduction (per 10 daphnids) Percent mortality First day of reproduction Reproduction per daphnid n# of Broods Brood size
0 229 0 4 22.9 2.9 8
0.5 208@ 0 3.9 20.8 2.9 7.3
1 178 0 4 17.8 2.9 6.1*
2 145 10 4 16.1* 3 5.4*
3.5 78 10 4.4 8.7* 2.4 3.4*
5 8 10 6.6* 0.9* 0.6* 1.8*
7 0 100* - - - -

* Significantly different from control (P<0.05)

@ Adjusted from 166 (n=8) to 208 (n=10)

Test substance was Linear Alkylbenzene Sulfonate (CAS # 68411 -30 -3).

 

Table 2. Chronic toxicity of LAS to Ceriodaphnia Sp.: Ohio River Water, algae-Trout Chow Diet (Study # 29717)

Concentration nTotal reproduction (per 10 daphnids) Percent mortality First day of reproduction Reproductio per daphnid n# of Broods Brood size
0 87 10 4.7 9.7 2.4 4
0.5 69 0 5 6.9 2.1 3.4
1 32 10 5.6* 3.6* 1.4* 2.4*
2 42 0 5 4.2* 1.8 2.2*
3.5 82 0 5.6* 8.2 2 4.2
5 104 0 4.7 11.6 2.3 4.9
7 15 100* 4 5.0* - 5

* Significantly different from control (P<0.05)

Test substance was Linear Alkylbenzene Sulfonate (CAS # 68411 -30 -3).

Validity criteria fulfilled:
yes
Remarks:
(controls met OECD 211 validity criteria of parent animal mortality not exceeding 20% at the end of the test and the mean number of live offspring produced per parent animal surviving at the end of the test is >/= 60)
Conclusions:
The effect of C11.8 LAS (linear alkylbenzene sulfonate) on Ceriodaphnia was evaluated in a 7-day chronic toxicity test in river water. The NOECs, based on reproduction and mortality, are 0.59 mg/L and 5.88 mg/L, respectively. These results are normalized to reflect the toxicity of an LAS with a carbon chain length of 11.6. The non-normalized NOECs are 0.5 mg/L and 5.0 mg/L for Ceriodaphnia fed a yeast or algae/trout chow diet, respectively. Results are based on nominal concentration of test substance (active ingredient).
Executive summary:

A 7-day chronic toxicity test of linear alkylbenzene sulfonate (C11.8 LAS) was conducted with Ceriodaphnia under semi-static conditions. The test medium was Ohio River water, and the Ceriodaphnia were fed either a yeast diet, or an algae/trout chow diet. The test medium was renewed 3x/7 days.

The nominal test concentrations were 0, 0.5, 1, 2, 3.5, 5 and 7 mg/L of active ingredient. Mortality and reproduction were monitored daily.  Results are based on the nominal concentration of the test substance. The 7 -day LC50 values were 5 -7 mg/L for both diets.

The 7 -day chronic NOECs may be summarized as follows:

 Diet

 NOEC normalized to C11.6 (mg/L)

 NOEC non-normalize

 Based on

 Yeast

 0.59

 0.5

 Reproduction

 Algae-Trout chow

 5.88 

 5

  Mortality and Reproduct

The chronic toxicity of LAS, in this 7 -day Ceriodaphnia test, compared quite favorably with the chronic toxicity of LAS in 21-day Daphnia magna tests.

Endpoint:
long-term toxicity to aquatic invertebrates
Type of information:
read-across based on grouping of substances (category approach)
Adequacy of study:
supporting study
Study period:
1996-08-26 to 1998-31-03
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
test procedure in accordance with generally accepted scientific standards and described in sufficient detail
Justification for type of information:
Refer to the section 13 of the dataset for details on the read across justification.
Reason / purpose:
reference to same study
Principles of method if other than guideline:
Invertebrates were caged in the tail pools of environmental stream mesocosms (the P&G Environmental Stream Facility, ESF) during a 56-day testing program with C12LAS (see section 6.1.8). Caged invertebrates were exposed for 32 days (chronic test).
GLP compliance:
no
Analytical monitoring:
yes
Details on sampling:
- Concentrations: All concentrations
- Sampling method: Water samples collected from both the stream mesocosm and the effluent stream.
- Sample storage conditions before analysis: Water samples were preserved with 1 - 3.5% formalin and were transported to P&G laboratories in Cincinnati.
NOTE: the analytical measurements are detailed in the robust summary of the stream mesocosm test (see section 6.1.8).
Vehicle:
no
Details on test solutions:
PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: The test chemical was metered into river water and allowed to flow through the streams on a continuous flow, once through basis. Details of test solution preparation and application to the experimental streams can be found in section 6.1.8.
- Eluate: N/A
- Differential loading: N/A
- Controls: River water only
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): N/A
- Evidence of undissolved material (e.g. precipitate, surface film, etc): N/A
Test organisms (species):
other: Corbicula, Elimia species, Hyalella azteca
Details on test organisms:
TEST ORGANISM
- Common name: Asiatic clam, freshwater snails, common scud (amphipod)
- Strain: N/A
- Source: Clams and snails were obtained from the Lower East Fork of the Little Miami River in the vicinity of Milford, Ohio. Hyalella azteca came from an in-house culture with original organisms obtained from Charles River Aquatic Research Organisms, Hampton, N.H.
- Age at study initiation (mean and range, SD): N/A
- Weight at study initiation (mean and range, SD): Asiatic clam (Corbicula) mean weight 0.70 g (SD 0.09 g), snails (Elimia species) mean weight 0.36 g (SD 0.092 g), amphipod (Hyalella azteca) mean weight 0.0027 g (SD 0.0006 g)
- Length at study initiation (length definition, mean, range and SD): Asiatic clam (Corbicula) mean length 10.9 mm (SD 0.44 mm)
- Valve height at study initiation, for shell deposition study (mean and range, SD): N/A
- Peripheral shell growth removed prior to test initiation: N/A
- Method of breeding: N/A
- Feeding during test: No. Food was not added to the stream mesocosm during the test. However, there is food naturally present in the dilution water (river water).
- Food type: Organisms were placed in the stream tail pools and allowed to feed on particles and organisms in the water.
- Amount: N/A
- Frequency: N/A


ACCLIMATION
- Acclimation period: 7 days (day -6 to 0)
- Acclimation conditions (same as test or not): same as test
- Type and amount of food: allowed to feed on particles and organisms in the water column
- Feeding frequency: N/A
- Health during acclimation (any mortality observed): N/A


QUARANTINE (wild caught)
- Duration: N/A
- Health/mortality: N/A
Test type:
flow-through
Water media type:
freshwater
Limit test:
no
Total exposure duration:
32 d
Remarks on exposure duration:
The stream mesocosms were dosed with C12LAS for 56 days. The caged invertebrates were exposed to C12LAS for 32 days in the tail pools.
Post exposure observation period:
N/A
Hardness:
140 mg/L as CaCO3 (average), SD 25 mg/L
Test temperature:
18 deg C (average), SD 3.6 deg C
pH:
7.8 - 8.3
Dissolved oxygen:
8.1 mg/L (average), SD 0.96 mg/L
Salinity:
N/A
Nominal and measured concentrations:
Nominal- 0 (control), 0.15, 0.3, 1.0, 3.0 mg/L
Measured- 0 (control), 0.126, 0.293, 0.927, 2.98 mg/L. Measured concentrations were 84 to 99% nominal. Results are based on measured concentrations.
Details on test conditions:
NOTE: the stream mesocosm is described in detail in robust summaries in section 6.1.8.
TEST SYSTEM
- Test vessel:
- Type (delete if not applicable): open
- Material, size, headspace, fill volume: A series of 10 meter long streams. There were five streams used in the current test. Each stream was at a unique concentration of C12LAS. The streams consist of a head tank, a gentle sloping (2 degree) periphyton region which is 40 cm across and 4 meters long, a macroinvertebrate region (4 degree slope, 60 cm x 4 meters), and a tail pool. The periphyton region contains unglazed terra cotta tiles to support a periphyton community. The macroivertebrate region contains cobble packed into trays for sampling of invertebrate communities.
- Aeration: natural aeration
- Type of flow-through (e.g. peristaltic or proportional diluter): continuous flow
- Renewal rate of test solution (frequency/flow rate): N/A
- No. of organisms per vessel: 20 of each species
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1
- No. of vessels per vehicle control (replicates): N/A
- Biomass loading rate: N/A


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: River water from the Lower East Fork of the Little Miami River in Milford, OH
- Total organic carbon: 7.2 mg/L average (SD 4.9 mg/L)
- Particulate matter: N/A
- Metals: N/A
- Pesticides: N/A
- Chlorine: N/A
- Alkalinity: 120 mg/L average as CaC03 (SD 17 mg/L)
- Ca/mg ratio: N/A
- Conductivity: 320 umhos/cm
- Culture medium different from test medium: no
- Intervals of water quality measurement: Water quality parameters were monitored throughout the test and change based on the meteorological and hydrological conditions in the area.


OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: N/A
- Light intensity: N/A


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Mortality and growth on days 0, 8, 16, and 32.

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 2-3
- Range finding study: No
Reference substance (positive control):
no
Key result
Duration:
32 d
Dose descriptor:
other: EC20
Effect conc.:
0.47 mg/L
Basis for effect:
other: growth weight
Remarks on result:
other: Normalized to carbon chain length 11.6
Duration:
32 d
Dose descriptor:
other: Corbicula: EC20
Effect conc.:
0.36 mg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
act. ingr.
Basis for effect:
growth
Remarks:
weight
Remarks on result:
other: 95% CL 0.278 - 0.470
Duration:
32 d
Dose descriptor:
other: Corbicula: EC20 based on body burden
Effect conc.:
0.044 other: mmoles/kg
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
act. ingr.
Basis for effect:
growth
Remarks:
weight
Remarks on result:
other: EC20 body burden values for growth endpoints calculated using the nonlinear iterative technique of Bruce and Versteeg (95% CL 0.0360 - 0.0546).
Duration:
32 d
Dose descriptor:
EC50
Effect conc.:
0.8 mg/L
Basis for effect:
other: growth weight
Remarks on result:
other: Normalized to carbon chain length 11.6
Duration:
32 d
Dose descriptor:
other: Corbicula: EC50
Effect conc.:
0.61 mg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
act. ingr.
Basis for effect:
growth
Remarks:
weight
Remarks on result:
other: 95% CL 0.519 - 0.720
Duration:
32 d
Dose descriptor:
other: EBB50 (Corbicula)
Effect conc.:
0.05 other: mmoles/kg
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
act. ingr.
Basis for effect:
growth
Remarks:
weight
Remarks on result:
other: EBB50 values for growth endpoints calculated using the nonlinear interative technique of Bruce and Versteeg. (95% CL 0.0454 - 0.0560)
Duration:
32 d
Dose descriptor:
other: EC20
Effect conc.:
0.35 mg/L
Basis for effect:
other: Growth length
Remarks on result:
other: Normalized to carbon chain length 11.6
Duration:
32 d
Dose descriptor:
other: EC20 (Corbicula)
Effect conc.:
0.27 mg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
act. ingr.
Basis for effect:
growth
Remarks:
length
Remarks on result:
other: 95% CL 0.204 - 0.352
Duration:
32 d
Dose descriptor:
other: EBB20 (Corbicula)
Effect conc.:
0.035 other: mmoles/kg
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
act. ingr.
Basis for effect:
growth
Remarks:
length
Remarks on result:
other: EBB20 values for growth endpoints calculated using the nonlinear interative technique of Bruce and Versteeg. (95% CL 0.031 - 0.0405)
Duration:
32 d
Dose descriptor:
EC50
Effect conc.:
0.84 mg/L
Basis for effect:
other: Growth length
Remarks on result:
other: Normalized to carbon chain length 11.6
Duration:
32 d
Dose descriptor:
other: EC50 (Corbicula)
Effect conc.:
0.64 mg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
act. ingr.
Basis for effect:
growth
Remarks:
length
Remarks on result:
other: 95% CL 0.540 - 0.760
Duration:
32 d
Dose descriptor:
other: Corbicula: EC50 based on body burden
Effect conc.:
0.048 other: mmoles/kg
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
act. ingr.
Basis for effect:
growth
Remarks:
length
Remarks on result:
other: EC50 body burden values for growth endpoints calculated using the nonlinear interative technique of Bruce and Versteeg. (95% CL 0.0449 - 0.0521) mmoles/kg
Key result
Duration:
32 d
Dose descriptor:
NOEC
Effect conc.:
3.81 mg/L
Basis for effect:
other: survival
Remarks on result:
other: Normalized to carbon chain length 11.6
Key result
Duration:
32 d
Dose descriptor:
other: NOEC (Elimia)
Effect conc.:
2.9 mg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
act. ingr.
Basis for effect:
other: survival
Duration:
24 d
Dose descriptor:
other: Elimia: EC20 based on body burden
Effect conc.:
0.031 other: mmoles/kg
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
act. ingr.
Basis for effect:
growth
Remarks:
weight
Duration:
24 d
Dose descriptor:
other: EC20
Effect conc.:
1.25 mg/L
Basis for effect:
other: Survival
Remarks on result:
other: Normalized to carbon chain length 11.6
Duration:
24 d
Dose descriptor:
other: Hyalella: EC20
Effect conc.:
0.95 mg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
act. ingr.
Basis for effect:
other: survival
Remarks on result:
other: Hyalella chronic test ended on day 24 as control mortality increased on day 32. (95% CL 0.597 - 1.29)
Duration:
24 d
Dose descriptor:
other: Hyalella: EC20 based on body burden
Effect conc.:
0.18 other: mmoles/kg
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
act. ingr.
Basis for effect:
other: survival
Remarks on result:
other: Hyalella chronic test ended on day 24 as control mortality increased on day 32. EBB20 values for growth endpoints calculated using the nonlinear interative technique of Bruce and Versteeg. (95% CL 0.113 - 0.245)
Duration:
24 d
Dose descriptor:
EC50
Effect conc.:
2.23 mg/L
Basis for effect:
other: Survival
Remarks on result:
other: Normalized to carbon chain length 11.6
Duration:
24 d
Dose descriptor:
other: Hyalella: EC50
Effect conc.:
1.7 mg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
act. ingr.
Basis for effect:
other: survival
Remarks on result:
other: Hyalella chronic test ended on day 24 as control mortality increased on day 32. (95% CL 1.33 - 2.16)
Duration:
24 d
Dose descriptor:
other: Hyalella: EC50 based on body burden
Effect conc.:
0.32 other: mmoles/kg
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
act. ingr.
Basis for effect:
other: survival
Remarks on result:
other: Hyalella chronic test ended on day 24 as control mortality increased on day 32. EBB50 values for growth endpoints calculated using the nonlinear interative technique of Bruce and Versteeg. (95% CL 0.252 - 0.410)
Details on results:
These experimental results were normalized to reflect a C11.6 chain length using a highly localized LAS-specific QSAR (Belanger et al, 2016). Toxicity normalization was performed using this basic fo rmula:

ChVc11.6norm = ChVx * (ChVc11.6pred / ChVxpred)

Where ChV is any chronic endpoint result; such as NOEC, LOEC, EC10, etc., ChVc11.6norm is the normalized ChV for the test material,
ChVx is the experimental ChV for the test material,
ChVc11.6pred is the QSAR predicted ChV for the target material with a chain length of C11.6, ChVxpred is the QSAR predicted ChV for a material with the same chain length as the test
material.

A QMRF is available on the QSAR (Belanger et al, 2016) used to provide the predicted results for normalization. More details on this approach are available in the endpoint summary.
Results with reference substance (positive control):
N/A
Reported statistics and error estimates:
Uptake and depuration were modeled as first order processes using BIOFAC to derive update (ku), depuration (kd), and kinetic bioconcentration factors (BCFkin) (Blau and Agin, 1978). Steady state bioconcentration factors (BCFss) were based on the ratio of measured body burdens to measured water concentrations. LC50 values were determined using the Bionomial or Probit methods. LBB50 (body burden associated with 50% mortality) were estimated from the BCF * LC50 and were based on the most appropriate BCF (kinetic or state state). The nonlinear iterative technique of Bruce and Versteeg (1992) was used to determine the ECx and EBBx values; where EC refers to the effective concentration in water that reduces the biological endpoint x% from controls, and EBB refers to the body burden concentration at which the biological endpoint was reduced x%. When an ECx could not be calculated, the NOEC is used and the body burden measured at that exposure concentration is reported.

Table 1. Concentration of C12LAS (mean (standard deviation), mg/L) and isomer distribution in streams during toxicity and accumulation portions of the study (WTDS# 44182).

Nominal concentration (mg/L) Measured1 C12LAS mg/L C12LAS2 isomer total mg/L 2-phenyl % 3-phenyl % 4-phenyl % 5,6-phenyl %
0 LQL3 LQL LQL LQL LQL LQL
0.15 0.126 (0.026) 0.165 (0.078) 32.6 (0.31) 19.7 (0.32) 15.2 (0.21) 32.5 (0)
0.30 0.293 (0.162) 0.296 (0.232) 33.5 (0.53) 19.6 (0.16) 14.8 (0.14) 32.1 (0.40)
1.0 0.927 (0.074) 0.83 33.8 19.4 15 31.9
3.0 2.98 (0.224) 2.78 (0.100) 35.2 (0.45) 19.7 (0.08) 14.6 (0.21) 30.4 (0.29)

1LC analysis of total LAS.

2LC-MS analysis.

3Less than the quantitation limit.

Table 2. Summary of acute and chronic endpoints for invertebrate species non-normalized (WTDS# 44182).

Species LC50 (95% CL) LC50 (body burden) (95% CL) Endpoint 32 day chronic exposure
EC20 (in mg/L) EC20 (body burden) mmoles/kg EC50 (95% CL) mg/L EC50 (body burden) (95% CL) mmoles/kg
Asiatic clam (Corbicula) > 3.0 > 0.078 Survival NE NE NE NE
Weight 0.36 (0.278-0.044) 0.044 (0.0360 - 0.0546) 0.61 (0.519 - 0.720) 0.05(0.0454 - 0.0560)
Length 0.27 (0.204-0.352) 0.035 (0.031-0.0405) 0.64 (0.540-0.760) 0.048 (0.0449-0.0521)
Snails (Elimia species) > 3.0 > 0.096 Survival NE NE NE NE
Weight N/A1 0.031 N/A N/A
Amphipod (Hyalella azteca)1 3.1 (2.53-4.24) 0.59 (0.480-0.804) Survival 0.95 (0.597-1.29) 0.18 (0.113-0.245) 1.7 (1.33-2.16) 0.32 (0.252-0.410)

NE = No effect for this endpoint, EC20 and NOEC greater than highest exposure concentration.

1The 24 day NOEC was 0.29 (32 day weights not available). However, snail growth was poor in controls and all treatments, and this endpoint is not considered reliable.

2Hyalella chronic test ended on day 24 as control mortality increased on day 32.

Note: acute toxicity tests are described in detail in sections 6.1.3 (acute invert).

Table 3. Body burdens of C12LAS isomers and total C12LAS (WTDS# 44182).

Species C12LAS Exposure Concentration (mg/L) Body Burden (mmoles/kg)
Total C12LAS Isomer position
2-phenyl 3-phenyl 4-phenyl 5,6-phenyl
Asiatic clam (Corbicula) LQL 0.0021 0.0009 0.0004 0.0003 0.0005
0.126 0.0119 0.0075 0.0019 0.0009 0.0015
0.293 0.0188 0.0125 0.0031 0.0011 0.0022
0.927 0.055 0.0406 0.0064 0.0026 0.0054
2.98 0.081 0.0604 0.0091 0.0044 0.0072
Snails (Elimiaspecies) LQL 0.0048 0.0024 0.0011 0.0006 0.0006
0.126 0.0153 0.0088 0.0039 0.0011 0.0016
0.293 0.0312 0.0175 0.0052 0.0023 0.0062
0.927 0.0493 0.0302 0.0055 0.004 0.0095
2.98 0.0965 0.0599 0.0129 0.0083 0.0153
Amphipod (Hyalella azteca) LQL 0.0249 0.0104 0.0062 0.0041 0.0041
0.126 0.0429 0.018 0.009 0.007 0.0089
0.293 0.0307 0.0174 0.0057 0.0038 0.0038
0.927 0.176 0.0872 0.0299 0.0241 0.0346

Corbicula, Elimia, and Hyalella were exposed to C12LAS for 32 days.

Validity criteria fulfilled:
yes
Remarks:
Validity criteria for OECD 211 fulfilled.
Conclusions:
The chronic toxicity of C12LAS was determined for 3 aquatic invertebrates, which were caged in the tailpools of a stream mesocosm study. The EC20s were 0.35 mg/L (Corbicula, based on growth), 3.81 mg/L (Elimia, based on survival; NOEC), and 1.25 mg/L (Hyalella, based on survival). Results are based on mean measured concentrations. These results are normalized to reflect the toxicity of an LAS with a carbon chain length of 11.6. The non-normalized results were 0.27 mg/L (Corbicula, based on growth; EC20), 2.9 mg/L (Elimia, based on survival; NOEC), and 0.95 mg/L (Hyalella, based on survival). Results are based on mean measured concentrations.
Executive summary:

The chronic toxicity of C12LAS was determined in a 32 day test with 3 aquatic invertebrates (Corbicula, Elimia, Hyalella). The invertebrates were caged in the tail pools of an environmental stream mesocosm study of C12LAS. Toxicity was based on water concentrations at which adverse effects were observed. Results were also calculated based on the tissue concentrations at which adverse effects were observed.

Invertebrates were exposed to nominal concentrations of 0, 0.15, 0.30, 1.0, and 3.0 mg a.i./L. Mean measured concentrations were 84 -99% of nominal, and results are based on measured concentrations. The invertebrates were acclimated to the stream mesocosm for 7 days prior to exposure to C12LAS. On days 0, 8, 16, and 32, the invertebrates were examined for growth and survival. There was one replicate per concentration--one stream, one tailpool per test concentration.

These results are normalized to reflect the toxicity of an LAS with a carbon chain length of 11.6 and are summarized as follows:

Invertebrate              Endpoint              Value (mg/L)              Based on

Corbicula                 EC20 (32 days)       0.35                     growth (length)

Elimia                      NOEC (32 days)       3.81                      survival

Hyalella                    EC20 (24 days)       1.25                     survival

The non-normalized values are 0.27 mg/L for Corbicula fluminea, 2.9 mg/L for Elimia and 0.95 mg/L for Hyallea aztecia (method: van de Plassche et al., 1999).

Endpoint:
long-term toxicity to aquatic invertebrates
Type of information:
read-across based on grouping of substances (category approach)
Adequacy of study:
supporting study
Study period:
1992-12-15 to 1994-07-12
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
test procedure in accordance with generally accepted scientific standards and described in sufficient detail
Justification for type of information:
Refer to the section 13 of the dataset for details on the read across justification.
Qualifier:
according to
Guideline:
other: Rotifer toxicity tests followed the method of Snell and Moffat (1992). A 2-d life cycle test with the rotifer Brachionus calyciflorus. Environ. Toxicol. Chem. 11: 1249
Deviations:
not specified
Principles of method if other than guideline:
The toxicity of a range of surfactant and surfactant related compounds was investigated in the two day whole life cycle bioassay with the rotifer, Brachionus calyciflorus. Compounds were selected to gain an understanting of how structural components, especially the polar head groups, contribute to toxicity.
GLP compliance:
not specified
Analytical monitoring:
yes
Details on sampling:
- Concentrations: All concentrations, daily
- Sampling method: N/A
- Sample storage conditions before analysis: N/A
Vehicle:
no
Details on test solutions:
PREPARATION AND APPLICATION OF TEST SOLUTION: Details not available in this study report. LAS was tested well below its solubility limit. No vehicle was used.
Test organisms (species):
other: Brachionus calyciflorus
Details on test organisms:
TEST ORGANISM
- Common name: planktonic rotifers
- Strain/clone: N/A
- Justification for species other than prescribed by test guideline: N/A
- Source: Bioresponse Systems, Inc. (Halifax, Nova Scotia, Canada)
- Age of parental stock (mean and range, SD): Rotifer cysts were hydrated with dilution water 20 hours prior to test initiation. Chronic toxicity tests were performed with six newly hatched (less than 3 hour old), swimming rotifers.
- Feeding during test
- Food type: green algae Selenastrum capricornutum and Chlorella vulgaris
- Amount: 1,000,000 cells/ml
- Frequency: N/A


ACCLIMATION
- Acclimation period: N/A
- Acclimation conditions (same as test or not): N/A
- Type and amount of food: N/A
- Feeding frequency: N/A
- Health during acclimation (any mortality observed): N/A

METHOD FOR PREPARATION AND COLLECTION OF EARLY INSTARS OR OTHER LIFE STAGES: N/A
Test type:
static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
2 d
Post exposure observation period:
N/A
Hardness:
152.1 mg/L as CaCO3
Test temperature:
25 ± 2 degrees C
pH:
8.55
Dissolved oxygen:
8.5 mg/L
Salinity:
N/A
Nominal and measured concentrations:
Details of nominal and measured concentrations are not available in the study report. Results are based on measured concentrations.
Details on test conditions:
TEST SYSTEM
- Test vessel:
- Type: N/A
- Material: 10 milliliters of test water containing an equal mixture of C. vulgaris and S. capriconutum at 1,000,000 cells/mL.
- Aeration: N/A
- Type of flow-through: N/A
- Renewal rate of test solution: N/A
- No. of organisms per vessel: 6
- No. of vessels per concentration (replicates): 3, with additional replicates used for analytical verification of test compound as needed.
- No. of vessels per control (replicates): 3
- Biomass loading rate: N/A

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: 50/50 blend of locally obtained well water and reverse osmosis water.
- Total organic carbon: N/A
- Particulate matter: N/A
- Metals: N/A
- Pesticides: N/A
- Chlorine: N/A
- Alkalinity: N/A
- Ca/mg ratio: N/A
- Conductivity: 449.7 umhos
- Culture medium different from test medium: N/A
- Intervals of water quality measurement: N/A
pH: 8.55
D.O.: 8.5
Hardness: 152.1 mg/L as CaCO3

OTHER TEST CONDITIONS
- Adjustment of pH: N/A
- Photoperiod: 16/8 hour light dark cycle
- Light intensity: low light conditions

EFFECT PARAMETERS MEASURED: All control and test concentration replicates were counted after 48 hours. Results are based on the total number of live, swimming organisms.

RANGE-FINDING STUDY
- Test concentrations: N/A
- Results used to determine the conditions for the definitive study: N/A
Reference substance (positive control):
yes
Remarks:
Pentachlorophenol and copper
Key result
Duration:
48 h
Dose descriptor:
EC10
Effect conc.:
1.77 mg/L
Basis for effect:
growth
Remarks on result:
other: EC10 was normalized to reflect the toxicity of LAS with a carbon chain length 11.6
Duration:
48 h
Dose descriptor:
EC10
Effect conc.:
1.18 mg/L
Nominal / measured:
meas. (TWA)
Conc. based on:
act. ingr.
Basis for effect:
growth
Remarks on result:
other: 95% CI not available
Duration:
48 h
Dose descriptor:
other: EC20
Effect conc.:
1.4 mg/L
Nominal / measured:
meas. (TWA)
Conc. based on:
act. ingr.
Basis for effect:
growth
Remarks on result:
other: 0.882 -2.27 mg/L
Duration:
48 h
Dose descriptor:
other: EC20
Effect conc.:
2.1 mg/L
Basis for effect:
growth
Remarks on result:
other: EC20 was normalized to reflect the toxicity of LAS with a carbon chain length 11.6
Duration:
48 h
Dose descriptor:
EC50
Effect conc.:
3 mg/L
Basis for effect:
growth
Remarks on result:
other: EC50 was normalized to reflect the toxicity of LAS with a carbon chain length 11.6
Duration:
48 h
Dose descriptor:
EC50
Effect conc.:
2 mg/L
Nominal / measured:
meas. (TWA)
Conc. based on:
act. ingr.
Basis for effect:
growth
Remarks on result:
other: 1.70 - 2.33 mg/L
Details on results:
These experimental results were normalized to reflect a C11.6 chain length using a highly localized LAS-specific QSAR (Belanger et al, 2016). Toxicity normalization was performed using this basic formula:

ChVc11.6norm = ChVx * (ChVc11.6pred / ChVxpred)

Where ChV is any chronic endpoint result; such as NOEC, LOEC, EC10, etc., ChVc11.6norm is the normalized ChV for the test material,
ChVx is the experimental ChV for the test material,
ChVc11.6pred is the QSAR predicted ChV for the target material with a chain length of C11.6, ChVxpred is the QSAR predicted ChV for a material with the same chain length as the test
material.

A QMRF is available on the QSAR (Belanger et al, 2016) used to provide the predicted results for normalization. More details on this approach are available in the endpoint summary.

- Mortality of parent animals: N/A
- No. of offspring produced per day per female: N/A
- Body length and weight of parent animals: N/A
- Type and number of morphological abnormalities: N/A
- Type and number of behavioural abnormalities: N/A
- Number of males and females (parental): N/A
- Time to first brood release or time to hatch: N/A
- Egg development time: N/A
- Brood size: N/A
- Time to sexual maturity: N/A
- Type and magnitude of biochemical changes: N/A
- Effect concentrations exceeding solubility of substance in test medium: No

Results with reference substance (positive control):
- Results with reference substance valid? Yes
- Relevant effect levels:
Pentachlorophenol: EC20 0.55 mg/L, EC50 1.3 mg/L
Copper: 0.012 mg/L (NOEC), 0.023 mg/L (LOEC)
Reported statistics and error estimates:
All control and test concentration replicates were counted after 48 hours. Statistical analyses were based on the total number of live, swimming animals. The 48-h EC20 and EC50 values with associated 95% confidence intervals were estimated by the iterative nonlinear regression technique described by Bruce and Versteeg. All statistical tests were performed with SAS version 6.0. The range of test concentrations for all 22 test compounds was 20 to 90%, but the specific decrease in LAS was not included in this study report. Measured concentrations were on the basis of time weighted average exposure.
Validity criteria fulfilled:
not specified
Remarks:
This test was well conducted by scientists with experience in aquatic testing, especially chronic invertebrate tests. There are no validity criteria for the Brachionus life cycle test.
Conclusions:
The effect of linear alkylbenzene sulfonate (C12.3 LAS) on the life-cycle of Brachionus calyciflorus (48 hours) was EC10 = 1.77 mg/L, EC20 = 2.1 mg/L, and EC50 = 3.0 mg/L, based on measured concentration of active ingredient. These results are normalized to reflect the toxicity of an LAS with a carbon chain length of 11.6. The non-normalized EC10, EC20 and EC50 are 1.18, 1.4 and 2.0 mg/L, respectively.
Executive summary:

The chronic toxicity of C12.3 LAS was evaluated in a 2 -day whole life cycle bioassay, using Brachionus calyciflorus (a rotifer). Brachionus is an alternative to Ceriodaphnia and Daphnia which require 7 and 21 days for chronic tests, respectively.

Six newly hatched rotifers (<3 hours old) were placed in each replicate beaker, and exposed to C12.3 LAS for 48 hours. Results were based on the total number of live, swimming organisms after 48 hours, and were based on measured concentrations. The live, swimming organisms included both adults and offspring.

The effect of linear alkylbenzene sulfonate (C12.3 LAS) on the life-cycle of Brachionus calyciflorus (48 hours) was EC10 = 1.77 mg/L, EC20 = 2.1 mg/L, and EC50 = 3.0 mg/L, based on measured concentration of active ingredient.  These results are normalized to reflect the toxicity of an LAS with a carbon chain length of 11.6. The non-no rmalized results are EC10 = 1.18 mg/L, EC20 = 1.4 mg/L, and EC50 = 2.0 mg/L.

In the study, a total of 22 surfactant and surfactant related compounds were tested. The non-normalized EC10 of C12.3 LAS to Brachionus (1.18 mg/L) compared quite favorably with the chronic NOECs for Daphnia magna and Ceriodaphnia referenced in the study (1.2 and 0.9 mg/L, respectively).

Endpoint:
long-term toxicity to aquatic invertebrates
Type of information:
experimental study
Adequacy of study:
supporting study
Study period:
From April 7, 1992 to July 1, 1992
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to
Guideline:
OECD Guideline 211 (Daphnia magna Reproduction Test)
Deviations:
yes
Remarks:
no analytical determinations and measurements of test concentrations
GLP compliance:
yes
Remarks:
OECD principles of Good Laboratory
Details on sampling:
- Concentrations: 0, 10, 18, 32, 56, 100 and 180 mg active /L
- Sampling frequency: 100 mL samples were taken in duplicate in polyethylene bottles from all test solutions at t = 1 d, t = 8 d and t = 15 d. One sample of each duplicate set was acidified with 2 M HCl to pH = 3.0-3.5
- Sample storage conditions: The samples were stored in a freezer and were sent to the sponsor,
only on his request, or disposed of one month after the delivery of the final report.
Analytical results are not available in this study report.
Vehicle:
no
Details on test solutions:
PREPARATION AND APPLICATION OF TEST SOLUTION:
Distilled water was used to prepare stock solutions of the test substance. New stock solutions were prepared on day = -1, 1, 3, 5, 7, 9, 13, 15, and 19.

Until Day 8: 0.18, 1.4. 2.5.4.4, 7.8 and 14.1 mL of test substance were diluted with distilled water to 25 mL, resulting in stock solutions of 31.6, 57.0, 101, 178, 316 and 571 g test substance /L respectively. From these stock solutions 0.315 mL (the actual dosed volumes varied between 0.27 and 0.32 mL) was dosed to 985 mL dilution water, resulting in dosed amounts of 10, 18, 32, 57, 101 and 183 mg/L respectively.

From Day 9: 1.6, 2.9, 5.2, 9.1 and 16.3 mL of test substance was diluted with distilled water to 25 mL, resulting in stock solutions of 64.8, 117.5, 210.6, 368.6 and 660.2 g of test substance/L respectively. From these stock solutions, 0.157 mL (the actual dosed volumes varied between 0.14 and 0.16 mL) was dosed to 985 mL dilution water, resulting in dosed amounts of 10, 19, 33.6, 58 and 104 mg/L respectively.

Due to slight variations in dosing, the test concentrations used in the report were rounded to 10, 18, 32, 56, 100, and 180 mg test substance/L.
Test organisms (species):
Daphnia magna
Details on test organisms:
TEST ORGANISM
- Common name: Water flea
- Strain/clone: Not reported
- Justification for species: Daphnia magna belongs, in accordance with the study guideline, to the suitable Daphnia types and was bred at the test facility
- Source: In house
- Maintenance of stock culture: Every week a number of cultures were started with approx. 125 daphnia of the same age (about 1 d old) in 4 L of dilution water. The cultures were fed daily with approx. 4 x 10(9) algal cells (Chlorella) and approx. 0.13 g of yeast per 4 L. The medium was completely replaced twice a week; at the same times all young born were removed. The cultures were kept at 20±1°C under a 16 h light and 8 h dark regime with a transition period with light of low intensity of a half hour. After 4 weeks, the cultures were discarded.
- Feeding during test: Yes
- Food type: Fed on Chlorella pyrenoidosa and some yeast was added as extra food. The food was added intermittently to the mixing bottles at the same time as the water and stock solution.
- Amount: After contact with the sponsor, it was decided to give the daphnia a minimum amount of food, because the observed precipitation may be caused by the presence of organic material. The amount of food added to the mixing bottle (content approx. 1L) was 10(8) algae cells and 2 mg yeast at each dosing time. From 14 d onwards, the amount of food was doubled. Due to a disturbance in the dosing system the amount of food dosed was only half of the intended amount at the end of the test.
- Frequency: Daily

ACCLIMATION
- Acclimation period: Not reported. However, daphnids were obtained in-house, cultured under the same conditions as the test
- Acclimation conditions: Same as test
- Type and amount of food: See description of culture above.
- Feeding frequency: See description of culture above.
- Health during acclimation: Not reported
Test type:
flow-through
Water media type:
freshwater
Limit test:
no
Total exposure duration:
21 d
Post exposure observation period:
None
Hardness:
210 mg/L CaCO3
Test temperature:
Test temperature range (as measured in control media): 20.1-20.5°C.
pH:
Overall pH range: 7.7 – 9.6. pH range at each test concentration was:
0 (control): 7.7 - 8.3
10 mg/L: 8.1 - 8.7
18 mg/L: 8.3 - 8.9
32 mg/L: 8.7 - 9.1
56 mg/L: 8.9 - 9.4
100 mg/L: 9.1 – 9.6
180 mg/L: 9.3 – 9.5
It is possible that the higher pH’s in the higher test concentrations may have contributed to the observed toxicity.
Dissolved oxygen:
Oxygen concentration range: 5.3-9.2 mg/L. The lowest oxygen concentration measured in the test and control media was 5.3 mg/L. Values just below the required 60% of the saturation value at 20°C (= 5.5 mg/L) were measured at t = 12 days at dosed amounts of 10 and 18 (5.3 mg O2/L) mg/L. It is unlikely that this incidentally low oxygen values affected the test results.
Nominal and measured concentrations:
Nominal test concentrations: 0, 10, 18, 32, 56, 100 and 180 mg active /L.
There was no measurement of test concentrations available in the study report.

Details on test conditions:
TEST SYSTEM
- Test vessel: Cylindrical retention chambers of an intermittent flow-through system
- Type: Open
- Material, size, headspace, fill volume: Each glass retention chamber was supplied with approx. 250 mL test solution
- Aeration: No
- Type of flow-through: Intermittent flow-through system. For details, refer to Any other information on materials and methods incl. tables’ section.
- Renewal rate of test solution: At intervals of 60 minutes, each of four replicate retention chambers was supplied with approx. 250 mL newly prepared solution (0.25 L per cycle).
- No. of organisms per vessel: 10 (except in control and at 18 mg/L, where 11 animals were used)
- No. of vessels per concentration: Four replicate compartments per concentration
- No. of vessels per control: Four replicate compartments per concentration
- Biomass loading rate: Control and 18 mg/L test vessel: 1 daphnia/ 23 mL; Biomass loading rate in all other concentrations: 1 daphnia/ 25 mL.

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: The dilution water used was DSWL, prepared from ground water. This medium was prepared by addition of several salts to groundwater from a locality near Linschoten (the Netherlands). The composition of media was
Sodium: 1.09 mmol/L
Potassium: 0.23 mmol/L
Calcium: 1.40 mmol/L
Magnesium: 0.80 mmol/L
Chloride: 2.96 mmol/L
Sulphate: 0.78 mmol/L
Hardness expressed as CaCO3 was 220 mg/L and total organic carbon content was 1.4 mg/L
- Culture medium different from test medium: No
- Intervals of water quality measurement: Temperature was measured three times per week in the control medium. pH values and oxygen concentrations were measured in all test solutions and control media three times per week (i.e. Day 0, 2, 5, 7, 9, 12, 14, 16, 19 and 21)

OTHER TEST CONDITIONS
- Adjustment of pH: No
- Photoperiod: 16/8 h light/dark cycle
- Light intensity: Not reported. However, yellow light was used test substance was light sensitive.

EFFECT PARAMETERS MEASURED: The dead animals and young born were counted and removed three times per week; the condition (swimming behavior, colour or any other visual observable morphological or behavioural criterion) and the size of the original test animals were qualitatively compared with those of the control animals. At the end of the test, all daphnia from the four retention chambers of each dosed amount were transferred to one vessel and their condition qualitatively compared with the control animals.

RANGE-FINDING STUDY: Yes. Appropriate dosages were determined in a semi-static preliminary range-finding test.
Details on the range finding study are not provided in the report.
Reference substance (positive control):
no
Duration:
21 d
Dose descriptor:
NOEC
Effect conc.:
18 mg/L
Nominal / measured:
nominal
Conc. based on:
act. ingr.
Basis for effect:
other: reproduction, mortality and visual appearance
Details on results:
- Mortality Results: The mortality in the controls was 12 out of 41 daphnia (29%), which was above the allowed 20% according the OECD Guideline, hence this study did not meet the validity criteria. A significant effect with regard to mortality was found at the concentration of 32 mg/L and the higher dosed amounts tested. No significant mortality was found at 18 mg/L and 10 mg/L (0% at 18 mg/L, and 18% at 10 mg/L).

- Morphological observation: At the end of the test, daphnia at 10 mg/L test concentration were bigger and darker than the control animals. At all test concentrations some pale animals were observed incidentally. At 10 and 18 mg/L, the daphnia were in somewhat better condition than the controls. At these concentrations no further effects on these criteria, which are somewhat subjective, were found. The appearance of pale daphnia was not taken into account for the estimation of the NOEC. Details are provided in the study report (Annex C).

- Reproduction: The average cumulative number of young in control was 39 which was below the number of 60, as required according to the Guideline (did not meet the validity criteria). This may be caused by the low amount of food given. However, at the two lowest test concentrations, there were 113 young/female (at 10 mg/L) and 64 young/female (at 18 mg/L).
The 21d EC50 (reproduction) could not be calculated because there was no dose-effect relationship and can therefore only be given as > 100 mg/L and < 180 mg/L. The observed stimulation of reproduction at low concentrations can possibly be caused by the presence of bacterial growth (extra food for the daphnia) on the slimy walls of the glassware. No significant inhibition of reproduction was found at any of the concentrations in which animals survived.

- Effect concentrations exceeding solubility of substance in test medium: No

- Observation of test media: The control medium was clear throughout the test and there were no precipitates on the glass ware. Deposits and flocks were observed in the test media, beginning on day 5. As a result, the retention chambers, test chambers and mixing bottles were cleaned several times during the test by rinsing with water. Precipitation might have been caused by the presence of organic matter. Details are provided in the study report (Table 1 of study report).
Reported statistics and error estimates:
- The LC50 values and their confidence interval were calculated by means of a parametric model
- Statistical significance for mortality was determined with a binomial test with a 95% and 99% significance level combining the results of the quadruplicates.
- Statistical significance for reproduction was determined with the two-tailed Dunnett-test with a 95% and 99% significance level using the mean number of young per female in each of the four replicates as observed values.
In both cases the observations at each concentration were compared with those of the control

Table 1: Daphnia magna Reproduction Test Results with Monoethanolamine (study# 35480)

Effects

Concentrations of MEA [mg/L]

 

Control

10

18

32

56

100

180

Average cumulative Number of young per female daphnia after 21 days exposure

39

113

64

33

44

30

-

Total number of surviving animals after 21 days

29

34

40

12*

11*

12*

0*

NOECreproduction, mortality and condition

18 mg/L

LOECreproduction, mortality and condition

32 mg/L

21 day LC50mortalitywith 95% Confidence Interval

40.7 mg/L (30.8 - 53.7 )

21 day EC50 reproduction**

> 100 mg/L and < 180 mg/L

*: Mortality significantly higher than control

*: Could not be calculated because there was no dose-effect relationship

* Test material was monoethanolamine (MEA), CAS # 141 -43 -5.

Validity criteria fulfilled:
no
Remarks:
The validity criteria for an OECD 211 test includes a maximum of 20% mortality in the controls, and a minimum of 60 young per control. In this test, control mortality was 29%, and there were 39 young/control.
Conclusions:
The 21 d NOEC of Monoethanolamine (MEA) to daphnia magna was 18 mg active/L based on reproduction, mortality and visual appearance. The result is based on nominal concentration.
Executive summary:

A 21 d chronic toxicity test of Monoethanolamine (MEA) to Daphnia magna was conducted under intermittent flow-through conditions, following OECD 211 guideline. The nominal test concentrations were 0, 10, 18, 32, 56, 100 and 180 mg active /L. There were 4 replicates for each test concentration and control. There was no measurement of test concentration.

The validity criteria for an OECD 211 test includes a maximum of 20% mortality in the controls, and a minimum of 60 young produced per control. In this test, the control mortality was 29%, and 39 young were produced per control. Hence, this test did not meet the validity criteria. However, at the two lowest test concentrations, there was only 7% mortality, and 88 young were produced per daphnid.

Significant mortality was observed at 32 mg/L and higher test concentrations.

Reproduction was not significantly inhibited at any test concentration in which daphnia survived, compared to the control. The highest test concentration in which Daphnia survived was 100 mg/L, and there was not a significant effect on reproduction at that concentration.

No treatment-related morphological observations were reported at 18 mg/L.

Therefore, the NOEC, based on mortality, reproduction and physical appearance was 18 mg active/L. The result is based on nominal concentration.

This Chronic toxicity test is classified as acceptable, and satisfies the guideline requirements for the OECD 211.

Description of key information

MEA-LAS dissociates into MEA and LAS in water. Since both MEA and LAS are readily biodegradable, chronic toxicity to the aquatic environment is not expected. Testing has however been conducted on MEA and LAS, and the key studies are presented. Toxicity values were normalized to reflect an LAS chain length of 11.6 using a robust and highly localized invertebrate LAS (Q)SAR (Belanger et al., 2016). The model was built from high quality toxicity data using pure LAS chain lengths (C10-14). Further external validation was performed using LAS mixtures with different average alkyl chain lengths. Reporting Format (QMRF) documents describing data quality, model development and performance of the model are appended to the Robust Study Summary (RSS).

Study 1 (C12 LAS): 

The effect of C12 LAS, sodium salt on an ecosystem in an indoor flowing stream mesocosm (model ecosystem) was determined. The mesocosm drew water from a high-quality stream (a National Scenic River) in southwestern Ohio, USA. Stream channels were naturally colonized by algae and invertebrates for 56 d prior to dosing.  

Five stream channels were dosed with the test substance at measured concentrations of 0, 126, 293, 927 and 2978 µg/L (84, 98, 93 and 99% of nominal values, respectively) for an additional 56 d. This mesocosm community was comprised of microbial heterotrophs, green, blue-green and diatom algae, and invertebrates. Invertebrate endpoints measured included densities of the invertebrate community, sensitive taxa (EPT), dominant taxa, selected ecologically important families (mayfly, caddisfly, true fly, midges and aquatic worms), emerging insects and drifting invertebrates. Taxonomic richness, Shannon diversity, functional feeding group composition and community-level multivariate response were derived. For algal populations and communities, algal cell and biovolume density for each dominant taxa and the algal community were determined. Taxonomic richness, Shannon diversity and community-level multivariate response were assessed. Ecological functional endpoints included heterotrophic activity and acclimation (amino acid uptake and surfactant mineralization) and autotrophic activity (bicarbonate uptake). Sorption, microbial biomass and microbial diversity shifts using phospholipid fatty acids (PLFA) were also evaluated. Assessments were conducted weekly to bi-weekly depending on the endpoint. Collectively, results for all taxa and endpoints were considered in determining the 56 d NOEC for the model ecosystem exposed to C12 LAS. 

The test substance did not impair the heterotrophic periphyton community. Taxonomic richness of algal communities was reduced only at the highest tested concentration of 2978 µg/L.  Abundance of lsonychia sp. (mayfly) and EPT fauna (Ephemeroptera, Plecoptera, Trichoptera) were also reduced at the highest concentration. Total abundance of invertebrates and abundance of Baetis sp. (mayfly) and Thienemannimyia sp. (chironomid) were reduced in the two highest concentrations. Based on these adverse effects, the most sensitive NOEC was concluded as 293 µg/L. Bioavailability of C12 LAS 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 that exposure was reduced by an average of 8.5 ± 8.9%. 

In this mesocosm model ecosystem, the 56 d NOEC for C12 LAS was 293 µg/L for most sensitive community, based on measured water column exposure and adjusted to 268 µg/L by the bioavailability model. This was based on a broad array of organisms that responded in similar time frames and concentrations (Belanger 1997, 2002 and 2004; Lower, 1996). 

Study 2 (C12 LAS): 

The chronic toxicity of C12 LAS, sodium salt was determined in a 32 d study with 3 aquatic invertebrates (Corbicula fluminea, Elimia sp. and Hyalella aztecia). The invertebrates were caged in the tail pools of an environmental stream mesocosm study of C12 LAS. Toxicity was based on water concentrations at which adverse effects were observed. Results were also calculated based on the tissue concentrations at which adverse effects were observed. Invertebrates were exposed to nominal concentrations of 0, 0.15, 0.30, 1.0 and 3.0 mg a.i./L. Mean measured concentrations were 84 -99% of nominal values and results were based on these measured concentrations. The invertebrates were acclimated to the stream mesocosm for 7 d prior to exposure. On Days 0, 8, 16 and 32, the invertebrates were examined for growth and survival. There was one replicate per concentration--one stream, one tailpool per test concentration.  These results are normalized to reflect the toxicity of an LAS with a carbon chain length of 11.6 (Belanger, 2016):

EC20 (32 d) = 0.35 mg/L for Corbicula fluminea, NOEC (32 d) = 3.81 mg/L for Elimia sp. and EC20 (24 d) = 1.25 mg/L for Hyallea aztecia. The non-normalized values are 0.27 mg/L for Corbicula fluminea, 2.9 mg/L for Elimia sp. and 0.95 mg/L for Hyallea aztecia (method: van de Plassche et al., 1999) (Versteeg, 2001 and 2003).

Study 3 (C10-13 LAS): 

The long-term toxicity of C10-13 LAS, sodium salt (average chain length C11.8) was evaluated in a 21 d survival and reproduction test with Daphnia magna according to OECD Guideline 211. Four replicates per concentration, with 5 organisms per replicate, were tested in a flow-through system (a modified Mount and Brungs proportional diluter). Mean measured concentrations were: 0, 0.32, 0.59, 1.18, 2.52 and 4.85 mg a.i./L (C11.8 LAS). Survival was monitored at 24 h, 96 h, 7 d and daily thereafter. Reproduction was monitored beginning with the production of the first brood on Day 7 or 8, and daily thereafter. LC50s and EC50s were calculated by probit analysis. Results were based on the mean measured concentration of the active ingredient. The 21 d NOEC was 1.18 mg/L, based on both survival and reproduction (equivalent to 1.35 mg/L when normalised to a carbon chain of C11.6). The 21 d LC50 was 1.67 mg/L (95% CL: 1.28 -2.18 mg/L) (equivalent to 1.91 mg/L when normalised to a carbon chain of C11.6; Belanger, 2016). The 21 d EC50s, based on total young production, average brood size and % days reproduction occurred, were 1.50, 2.30 and 2.31 mg/L, respectively (equivalent to 1.72, 2.63 and 2.65 mg/L when normalised to a carbon chain of C11.6; Belanger, 2016) (Maki, 1977 and 1979).  

Study 4 (C10-13 LAS)  

A 7 day toxicity test of C10-13 LAS, sodium salt (average chain length C11.8) was conducted with Ceriodaphnia under semi-static conditions according to a method comparable to OECD Guideline 211. The test medium was Ohio River water and the Ceriodaphnia were fed either a yeast diet or an algae/trout chow diet. The test medium was renewed 3 times in 7 days. The nominal test concentrations were 0, 0.5, 1, 2, 3.5, 5 and 7 mg a.i./L. Mortality and reproduction were monitored daily. Results were based on nominal concentrations. The 7 d LC50 was 5 - 7 mg/L for both diets. The NOECs, based on reproduction and mortality, were 0.59 and 5.88 mg/L, respectively. These results are normalized to reflect the toxicity of a LAS with a carbon chain length of 11.6 (Belanger, 2016). The non-normalized NOECs are 0.5 and 5.0 mg/L for Ceriodaphnia fed a yeast or algae/trout chow diet, respectively (Taylor, 1984).

Study 5 (C10-14 LAS) 

The chronic toxicity of C10-14 LAS (average chain length C12.3) was evaluated in a 2 d whole life cycle bioassay using the rotifer Brachionus calyciflorus. Brachionus is an alternative to Ceriodaphnia and Daphnia which require 7 and 21 d for chronic tests, respectively. Six newly hatched rotifers (<3 h old) were placed in each replicate beaker and exposed to the test substance for 48 h. Results were based on the total number of live, swimming organisms after 48 h. The live, swimming organisms included both adults and offspring. The EC10 was equivalent to 1.77 mg/L, the EC20 was 2.1 mg/L and the EC50 was 3.0 mg/L, based on measured active ingredient concentrations. These results are normalized to reflect the toxicity of a LAS with a carbon chain length of 11.6 (Belanger, 20156). The non-normalized results are EC10 = 1.18 mg/L, EC20 = 1.4 mg/L and EC50 = 2.0 mg/L. In the study, a total of 22 surfactant and surfactant-related compounds were tested. The non-normalized EC10 of C12.3 LAS to Brachionus (1.18 mg/L) compared quite favorably with the chronic NOECs for Daphnia magna and Ceriodaphnia referenced in the study (1.2 and 0.9 mg/L, respectively) (Procter & Gamble, 1996; OECD SIDS, 2005; Belanger et al., 2016).

Study 6 (MEA):

A 21 d chronic toxicity test with monoethanolamine (MEA) in Daphnia magna was conducted under intermittent flow-through conditions, following OECD Guideline 211. The nominal test concentrations were 0, 10, 18, 32, 56, 100 and 180 mg a.i./L. There were 4 replicates for each test concentration and control. There was no measurement of test concentrations. The validity criteria includes a maximum of 20% mortality in the controls and a minimum of 60 young produced per control. In this test, the control mortality was 29% and 39 young were produced per control. Hence, it did not meet the validity criteria. However, at the two lowest test concentrations, there was only 7% mortality and 88 young were produced per daphnid. Significant mortality was observed at 32 mg/L and higher test concentrations. Reproduction was not significantly inhibited at any test concentration in which Daphnia survived (up to and including 100 mg a.i./L), compared to the control. No treatment-related morphological observations were reported at 18 mg a.i./L. Therefore, the NOEC, based on mortality, reproduction and physical appearance was 18 mg a.i./L (nominal) (Hooftman, 1992).

Key value for chemical safety assessment

EC10, LC10 or NOEC for freshwater invertebrates:
0.268 mg/L

Additional information

The point of departure for aquatic PNEC derivation is the 56 d NOEC of 0.268 mg/L from a mesocosm model ecosystem (Belanger, 1997, 2002 and 2004; Lowe, 1996).