Reaction mass of N,N-dimethyldodecanamide and N,N-dimethyltetradecanamide

Toxicity to aquatic algae and cyanobacteria

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2015-01-28 - 2015-10-01

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Freshwater Alga and Cyanobacteria, Growth Inhibition Test)

Qualifier:

according to guideline

Guideline:

EU Method C.3 (Algal Inhibition test)

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

- Name of test substance: N,N Dimethyldodecane-1-amide
- Test substance No.: 13/0555-1
- Batch-Identification: 0009565072
- CAS No.: 3007-53-2
- Purity: N,N-Dimethyldodecanamide: 95.9 area-%; dodecanoic acid (lauric acid): 2.26 area-%
- Homogeneity: Homogeneous
- Storage stability: The stability of the test substance under storage conditions over the test period was guaranteed by the sponsor, and the sponsor holds this responsibility.
- Chemical Name: Dodecanamide, N,N-dimethyl-
- Date of production: 15-03-2013
- Expiry date: 15-03-2016
- Physical state/ Appearance: liquid/ colorless, clear
- Density: 0.864 g/mL
- Water solubility: 28.02 mg/L at 20°C
- Storage conditions: The test substance was stored at ambient temperature.

Analytical monitoring:

yes

Details on sampling:

- Samples preparation: Prior to use the test substance container was shaken to ensure homogeneity before weighing. The stock solution (11.1 mg/L) was prepared by pipetting 22.2 mg (25.7 µL based on the density 0.864 g/mL) test substance into 2 L of test medium and stirring for about one day. The test samples were delivered as aliquots of 20 mL in sealed vials. After addition of a spatula tip of NaCI and 2 mL of ISTD solution, the vials were re-sealed and shaken for 120 min for extraction. The organic layer was removed for analysis.

- Concentrations: The lower test concentrations were prepared by diluting this stock solution. Before diluting, the stock solution was checked for complete dissolution of the test substance.

- Sampling method: The samples were taken at the start of the exposure (0 h) from the inoculated replicate 7 of each concentration and the control and at the end of the exposure (72 h) from the combined inoculated (+ algae) replicates of the test concentrations and of the combined inoculated control group replicates. Additionally, samples were collected from the uninoculated (-algae) replicate 0 of each test concentration and the control at the end of the exposure (72 h).

- Undissolved material observed: No undissolved test substance was observed after 1 day stirring and the stock solution appeared colorless and clear. The test solutions were visibly homogeneous.

- Stability and homogeneity: The test substance is readily and rapidly biodegradable. The test substance was demonstrated to be potentially adsorptive to glass containers in a preliminary investigation; therefore the test vessels were conditioned with the corresponding test solution for approx. one day before the start of exposure. The stability of the test substance as a solution in test water and under testing conditions was determined by concentration control analysis.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: The test medium (OECD medium) was prepared according to OECD 201. The test medium was sterilized after preparation.
- Controls: Blank control and positive control
- Evidence of undissolved material: No

Test organisms (species):

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

Details on test organisms:

TEST ORGANISM
- Common name: Pseudokirchneriella subcapitata KORSHIKOV (SAG 61.81), formerly known as Selenastrum capricornutum, and currently renamed as Raphidocelis subcapitata KORSHIKOV
- Source (laboratory, culture collection): Collection of algal cultures in University of Göttingen /Germany. SAG (Collection of algal cultures in Göttingen, Germany).
- Age of inoculum (at test initiation): 0 days
- Method of cultivation: A stock algal culture is maintained continuously at the test facility. Before the exposure an inoculum culture is prepared from the stock culture and incubated for 4 days at 21 – 24 °C (max. temperature difference 2 °C). After this time, the inoculum culture is in exponential growth phase and can be used to initiate the test (study day 0).

ACCLIMATION
- Culturing media and conditions: same as test
- Any deformed or abnormal cells observed: No

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Post exposure observation period:

Not performed

Hardness:

No data

Test temperature:

22.6 – 23.0 °C

pH:

7.8 - 8.0

Dissolved oxygen:

No data

Salinity:

No data

Nominal and measured concentrations:

- Nominal concentrations: 0 (control), 0.46, 1.0, 2.2, 4.6, 10 mg/L as nominal concentrations based on test substance density without correction for purity.
- Measured concentration: 0 (control), 0.35, 0.82, 1.80, 3.62, 8.45 mg/L as geometric mean measured concentrations.

Details on test conditions:

TEST SYSTEM
- Test vessel: Erlenmeyer flasks (nominal volume 250 mL) plugged with gas permeable silicone sponge caps
- Initial cells density: 0.5 x 10E4 cells/mL
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 6
- No. of vessels per test group for initial concentration control analysis (replicates): 1
- Inoculum culture: An inoculum culture in exponential growth phase was prepared with an aliquot of the stock algal culture added to sterile test media to provide an initial cell density of 0.5 x 10E4 cells/mL. The inoculum culture is incubated under test conditions for 4 days prior to test initiation. The increase in biomass is verified to ensure that growth is within the normal range and algal cells are examined microscopically for normal morphology prior to use for test inoculation.
- Inoculum culture cell density (4 days growth): 249 x 10E4 cells/mL (498 fold increase)
- Inoculum culture morphology: normal and healthy
- Insertion of test organisms: The cell density of the inoculum culture in exponential growth phase was determined and then adjusted to 5 x 10E4 cells/mL. To obtain the correct initial cell density in the test replicates of 0.5 x 10E4 cells/mL and the correct nominal concentrations of the test solutions, inoculum culture was added to each 111 % stock test solution at a ratio of 1:10.

GROWTH MEDIUM
- Standard medium used: yes

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Test media according to OECD guideline
- Intervals of water quality measurement: The temperature was continuously measured during the whole test period in the climate chamber in a separate deionized water filled flask. pH and fluorescence were measured after 0 and 72 hours.

OTHER TEST CONDITIONS
- Sterile test conditions: yes/no
- Adjustment of pH: No
- Photoperiod: permanent
- Light intensity and quality: Average 6815 lux (within ± 15% variability) at a wave length of 400 - 700 nm.
- Illumination: Artificial light, type universal white (OSRAM L 25), permanent illumination. To minimize the potential effect of slight variations in illumination, the test vessels were rearranged daily.

EFFECT PARAMETERS MEASURED: Algal growth measured as in vivo chlorophyll-a fluorescence (pulsed excitation with light flashes having a wavelength of 430 nm) after 72 hours.

OBSERVATIONS AND MEASUREMENTS:
- Fluorescence measurement: The fluorescence of aliquots from each test vessel was measured using a Tecan Infinite 200Pro fluorometer in a 96-well flat bottom black plate with the following parameters: fluorescence top reading; excitation / emission wavelength = 430 / 670 nm; excitation / emission bandwidth = 20 / 25 nm; flashes = 5; integration time = 20 µs; shaking duration = 15s; shaking amplitude = 6 mm.

- Determination of correlation between fluorescence and cell density: After the end of the exposure the control replicates were mixed and serially diluted by factor 2. The fluorescence of aliquots from the undiluted mixture and the dilutions were measured and in parallel cell density was determined by a direct microscopic count (two counts in a Neubauer haemocytometer). These data were used to derive a linear correlation between fluorescence and cell density.

- Algal morphology: The inoculum culture was observed microscopically at the start of the test to verify normal and healthy cells. At test termination, a pooled sample from each test concentration was examined and any abnormal appearance of the algae noted.

- Light measurement: Light homogeneity was evaluated by measuring light intensity at 5 locations within the incubation area at the start and end of the test (Testo 545 light meter, Testo GmbH & Co, Lenzkirch, Germany). The light intensity did not vary by more than ± 15% over the incubation area.

- Determination of cell concentrations: The mean fluorescence was determined after 0, 24, 48, 72 h and converted to cell density using a correlation curve derived from a microscopic count of the control. The commercial software "TOXRAT Professional 2.10" (ToxRat Solutions GmbH, Alsdorf, Germany) was used for the statistical evaluation of the data. The yield and specific growth rate over the exposure period was calculated for each replicate flask of each test group and inhibition for each test group was determined by comparison to the control. The percent inhibition of the mean yield and growth rate compared to the control was calculated for each test group replicate. The data were illustrated using plots of percent inhibition (response) versus concentration.

TEST CONCENTRATIONS
- Spacing factor for test concentrations: ≤ 3.2
- Range finding study: Yes
- Results used to determine the conditions for the definitive study: The test concentrations were selected on the basis of a range finding test (experimental conduct in accordance with GLP but without a GLP Status). The results of the 72 hour range finding test were (as nominal concentrations): EyC50 = between 0.1 and 1 mg/L (0.75 mg/L estimated); ErC50 = between 1 and 10 mg/L (3.49 mg/L estimated).
- Test concentrations:
Nominal concentrations: 0 (control), 0.46, 1.0, 2.2, 4.6, 10 mg/L as nominal concentrations based on test substance density without correction for purity.
Measured concentration: 0 (control), 0.35, 0.82, 1.80, 3.62, 8.45 mg/L as geometric mean measured concentrations.

Reference substance (positive control):

yes

Remarks:

Potassium dichromate (K2Cr2O7)

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

0.311 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

biomass

Remarks on result:

other: 95 % C.L. (0.30 - 0.32 mg/L)

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

0.494 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

biomass

Remarks on result:

other: 95 % C.L (0.48 -0.51 mg/L)

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

> 0.351 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

biomass

Duration:

72 h

Dose descriptor:

LOEC

Effect conc.:

0.351 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

biomass

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

0.435 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: 95 % C.L. (0.40 - 047 mg/L)

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

0.805 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: 95 % C.L (0.75 - 0.83 mg/L)

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

0.351 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

LOEC

Effect conc.:

0.82 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

Details on results:

The following effect concentrations (mg/L) were obtained after 72-h based on nominal concentration: The 72-hour ErC50 value was determined to be 0.99 mg test item/L and the 72-hour EyC50 was determined to be 0.629 mg test item/L. The 72-hour NOErC and the 72-hour NOEyC were determined to be 0.46 mg/L and greater than 0.46 mg test item/L respectively and the associated 72- hour LOErC and LOEyC were determined to be 1 and 0.46 mg/L respectively.
The following effect concentrations (mg/L) were obtained after 72-h based on geometric mean measured concentration: The 72-hour ErC50 value was determined to be 0.805 mg test item/L and the 72-hour EyC50 was determined to be 0.494 mg test item/L. The 72-hour NOErC and the 72-hour NOEyC were determined to be 0.351 mg/L and greater than 0.351 mg test item/L respectively and the associated 72- hour LOErC and LOEyC were determined to be 0.82 and 0.351 mg/L respectively.

Results with reference substance (positive control):

The ErC50 (72 h) of the control substance potassium dichromate was 1.179 mg/L. According to the test ISO guideline 8692 the EC50 values of the reference substance potassium dichromate was in the range: ErC50 = 0.92 – 1.46 mg/L after 72 hours for Pseudokirchneriella subcapitata, therefore the results with the reference substance for Pseudockirchneriella subpicata were valid.

Reported statistics and error estimates:

ECx values and confidence limits were calculated by probit analysis (Finney, 1971). The LOEC was determined by comparing the means of the calculated yield or growth rate of the various concentration levels with the control using Dunnett’s multiple t-test (one-sided). The NOEC was the next tested concentration below the LOEC.

Validity criteria fulfilled:

yes

Conclusions:

The influence of the test substance on the growth of the freshwater algae Pseudokirchneriella subcapitata KORSHIKOV was assessed in a static dose response test according to OECD 201 (2006). The 72-hour ErC50 was determined to be 0.805 mg test item/L, the 72-hour NOErC was determined to be 0.351 mg test item/L and the associated 72-hour EC10 was determined to be 0.435 mg test item/L. All values were based on geometric mean measured concentrations.

Executive summary:

The toxicity of the test substance to the freshwater alga Pseudokirchneriella subcapitata KORSHIKOV was determined according to the principles of OECD 201 (2006) and the Commission Regulation (EC) No 761/2009/C3 (2009) under GLP conditions. The aim of the study was to assess the effects on growth rate and yield over a period of 72 hours. The study was conducted under static conditions. This study encompassed 6 treatment groups (5 dose rates of the test item, control) with three replicates per test concentration and six replicates for the control. At test start 100 mL of the test concentrations were inoculated with 5000 algal cells per mL test medium and defined volumes of the algal suspensions were sampled after 0, 24, 48 and 72 hours for determination of cell densities by spectrophotometrical measurement. The samples of the test media sampled at the start and at the end of the test after 72 hours of exposure were analyzed via capillary gas chromatography - mass spectrometry (GC-MS). The nominal test concentrations of 0.46, 1.0, 2.2, 4.6, 10 mg test item/L and a control are corresponding to geometric mean measured concentrations of 0.35, 0.82, 1.80, 3.62, 8.45 mg test item/L and control (0 mg test item/L). The measured concentrations of the test substance in the test water were in a range of 74 - 84 % of the nominal concentration at start of exposure. After 72 hours, the measured concentrations remained within ± 20 % of the initially measured concentration in test groups > 1 mg/L. In the lower test groups, > 20 % of the test substance was lost in the algae inoculated samples. The decrease at the end of exposure was most likely due to binding (adsorption) of the test substance to the growing algal biomass in the lower concentrations. To evaluate adsorption to algae, additional samples were analyzed from the uninoculated replicate 0 of each test group and the control at the end of the exposure (72 h). All uninoculated replicates were within ± 20 % of the initially measured concentrations. OECD 201 states that the alga growth inhibition test is a more dynamic test system than most other short term aquatic toxicity tests. Disappearance of the test substance from solution by adsorption to the increasing algal biomass does not mean that it is lost from the test system. Consequently, the results demonstrate the consistency of test substance concentrations over the defined exposure period and the geometric mean measured concentrations calculated using the uninoculated replicates were used to evaluate the results.

The following effect concentrations (mg/L) were obtained after 72-h based on nominal concentration: The 72-hour ErC50 value was determined to be 0.99 mg test item/L and the 72-hour EyC50 was determined to be 0.629 mg test item/L. The 72-hour NOErC and the 72-hour NOEyC were determined to be 0.46 mg/L and greater than 0.46 mg test item/L, respectively and the associated 72- hour LOErC and LOEyC were determined to be 1 and 0.46 mg/L, respectively.

The following effect concentrations (mg/L) were obtained after 72-h based on geometric mean measured concentration: The 72-hour ErC50 value was determined to be 0.805 mg test item/L and the 72-hour EyC50 was determined to be 0.494 mg test item/L. The 72-hour NOErC and the 72-hour NOEyC were determined to be 0.351 mg/L and greater than 0.351 mg test item/L, respectively and the associated 72- hour LOErC and LOEyC were determined to be 0.82 and 0.351 mg/L, respectively.

Reference 2

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Study period:

2015-01-28 - 2015-10-01

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH
1. HYPOTHESIS FOR THE ANALOGUE APPROACH
The chemical characterisation and physico-chemical properties of the source and target substances support read-across between the substance for acute ecotoxicity endpoints.
2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)
Source: N,N-dimethyldodecanamide [EC 221-117-5; CAS 3007-53-2].
Target: Reaction mass of N,N-dimethyldodecanamide and N,N-dimethyltetradecanamide [EC not assigned; CAS not assigned]. Details of composition provided in section 1.2.
3. ANALOGUE APPROACH JUSTIFICATION
The source substance constitutes 65-80 %w/w of the target substance. The other main constituent (20-35 %w/w) has identical functional groups and an additional two carbons in the alkyl chain. The similarity of the measured water solubility and log Kow for the source substance and the measured water solubility and estimated log Kow for the target substance suggests that both substances will behave similarly in aquatic systems and that data available for the source may be used to read across to the target.
4. DATA MATRIX
Source: Water solubility = 28.08 mg/L (OECD TG 105); Log Kow = 5.2 (OECD TG 117); Readily biodegradable (86% after 28 days; OECD TG 301B);
96-h LC50 > 0.88 mg/L (Danio rerio; OECD TG 203); 48-h EC50 = 0.313 mg/L (Daphnia magna; OECD TG 202); 72-h ErC50 = 0.805 mg/L; 72-h NOErC = 0.351 mg/L (Pseudokirchneriella subcapitata; OECD TG 201), 3-h EC50 = 170 mg/L; EC10 = 20 mg/L (activated sewage sludge; OECD TG 209)
Target: Water solubility = 43.61 mg/L (EU Method A.6); Log Kow >4.6 (estimate from solubility in n-octanol and water)
Ecotoxicological endpoints – no data

Reason / purpose for cross-reference:

read-across source

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Freshwater Alga and Cyanobacteria, Growth Inhibition Test)

Qualifier:

according to guideline

Guideline:

EU Method C.3 (Algal Inhibition test)

Post exposure observation period:

Not performed

Salinity:

No data

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

0.311 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

biomass

Remarks on result:

other: 95 % C.L. (0.30 - 0.32 mg/L)

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

0.494 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

biomass

Remarks on result:

other: 95 % C.L (0.48 -0.51 mg/L)

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

> 0.351 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

biomass

Duration:

72 h

Dose descriptor:

LOEC

Effect conc.:

0.351 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

biomass

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

0.435 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: 95 % C.L. (0.40 - 047 mg/L)

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

0.805 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: 95 % C.L (0.75 - 0.83 mg/L)

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

0.351 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

LOEC

Effect conc.:

0.82 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

Description of key information

The following effect concentrations (mg/L) were obtained based on geometric mean measured concentration:

72-hour ErC50 = 0.805 mg/L

72-hour EyC50 = 0.494 mg/L

72-hour NOErC and 72-hour NOEyC = 0.351 mg/L > 0.351 mg test item/L, respectively.

Test species: Pseudokirchneriella subcapitata

Test substance: N,N-dimethyldodecanamide

Key value for chemical safety assessment

EC50 for freshwater algae:

0.805 mg/L

EC10 or NOEC for freshwater algae:

0.351 mg/L

Additional information

The toxicity of the test substance, N,N-dimethyldodecanamide, to the freshwater alga Pseudokirchneriella subcapitata KORSHIKOV was determined according to the principles of OECD 201 (2006) and the Commission Regulation (EC) No 761/2009/C3 (2009) under GLP conditions. The aim of the study was to assess the effects on growth rate and yield over a period of 72 hours. The study was conducted under static conditions. This study encompassed 6 treatment groups (5 dose rates of the test item, control) with three replicates per test concentration and six replicates for the control. At test start 100 mL of the test concentrations were inoculated with 5000 algal cells per mL test medium and defined volumes of the algal suspensions were sampled after 0, 24, 48 and 72 hours for determination of cell densities by spectrophotometrical measurement. The samples of the test media sampled at the start and at the end of the test after 72 hours of exposure were analyzed via capillary gas chromatography - mass spectrometry (GC-MS). The nominal test concentrations of 0.46, 1.0, 2.2, 4.6, 10 mg test item/L and a control are corresponding to geometric mean measured concentrations of 0.35, 0.82, 1.80, 3.62, 8.45 mg test item/L and control (0 mg test item/L). The measured concentrations of the test substance in the test water were in a range of 74 - 84 % of the nominal concentration at start of exposure. After 72 hours, the measured concentrations remained within ± 20 % of the initially measured concentration in test groups > 1 mg/L. In the lower test groups, > 20 % of the test substance was lost in the algae inoculated samples. The decrease at the end of exposure was most likely due to binding (adsorption) of the test substance to the growing algal biomass in the lower concentrations. To evaluate adsorption to algae, additional samples were analyzed from the uninoculated replicate 0 of each test group and the control at the end of the exposure (72 h). All uninoculated replicates were within ± 20 % of the initially measured concentrations. OECD 201 states that the alga growth inhibition test is a more dynamic test system than most other short term aquatic toxicity tests. Disappearance of the test substance from solution by adsorption to the increasing algal biomass does not mean that it is lost from the test system. Consequently, the results demonstrate the consistency of test substance concentrations over the defined exposure period and the geometric mean measured concentrations calculated using the uninoculated replicates were used to evaluate the results.

The following effect concentrations (mg/L) were obtained after 72-h based on nominal concentration: The 72-hour ErC50 value was determined to be 0.99 mg test item/L and the 72-hour EyC50 was determined to be 0.629 mg test item/L. The 72-hour NOErC and the 72-hour NOEyC were determined to be 0.46 mg/L and greater than 0.46 mg test item/L, respectively and the associated 72- hour LOErC and LOEyC were determined to be 1 and 0.46 mg/L, respectively.

The following effect concentrations (mg/L) were obtained after 72-h based on geometric mean measured concentration: The 72-hour ErC50 value was determined to be 0.805 mg test item/L and the 72-hour EyC50 was determined to be 0.494 mg test item/L. The 72-hour NOErC and the 72-hour NOEyC were determined to be 0.351 mg/L and greater than 0.351 mg test item/L, respectively and the associated 72- hour LOErC and LOEyC were determined to be 0.82 and 0.351 mg/L, respectively.

The results of this study are read-across to Reaction mass of N,N-dimethyldodecanamide and N,N-dimethyltetradecanamide.