Dodecanenitrile

Toxicity to microorganisms

Link to relevant study record(s)

Reference

Endpoint:

toxicity to microorganisms, other

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

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

Justification for type of information:

Data is from peer reveiwed journal.

Qualifier:

according to guideline

Guideline:

other: As mention below

Version / remarks:

No data available

Deviations:

not specified

Principles of method if other than guideline:

Toxicity of (Dodecanenitrile) to micro-organisms study was conducted on Tetrahymena pyriformis strain GL for 40 hrs.

GLP compliance:

not specified

Specific details on test material used for the study:

- Name of test material: Dodecanenitrile
- Molecular formula: C12H23N
- Molecular weight: 181.321 g/mole
- Smiles notation: C(CCCCCC)CCCCC#N
- InChl: 1S/C12H23N/c1-2-3-4-5-6-7-8-9-10-11-12-13/h2-11H2,1H3
- Substance type: organic
- Physical state: colourless liquid

Analytical monitoring:

not specified

Details on sampling:

- Concentrations: Five different test substance conc. was used for the study, but exact conc. was not reported.
- Sampling method: In most cases, a solvent other than sterile distilled water is used for preparing the stock solution of test chemical. The solvent of choice is a reagent grade dimethyl sulfoxide (DMSO). This solvent has low toxicity to Tetrahymena, low volatility, and high ability to dissolve organic chemicals. Concentration not greater than 0.75% DMSO (350 µL per 50 mL of medium) are used. This conc. was shown to have no effect on Tetrahymena population growth. Standard stocks are prepared on a milligram per liter basis. When using distilled water to prepare stock solutions, extra care must be taken to maintain sterility. In some case, the test chemical was added directly to the growth medium in the –Erlenmeyer flasks, but they are usually dissolved in a solvent to form a stock solutions. If a stock solution was used, the solutions are prepared just prior (i.e, within 1 hr) to use. Despite the potential for volatilization, in some cases, sonications was used in the preparation of stock solutions.

- Sample storage conditions before analysis: No data available

Vehicle:

yes

Remarks:

DMSO and sterile distilled water was used as a vehicle.

Details on test solutions:

No data available

Test organisms (species):

other: Tetrahymena pyriformis strain GL

Details on inoculum:

- Laboratory culture: The test culture Tetrahymena pyriformis strain GL was obtained from John R. Kennedy, Department of Biochemistry, Cell and Molecular Biology, The University of Tennessee – Knoxville.

- Name and location of sewage treatment plant where inoculum was collected: No data

- Method of cultivation: Tests were conducted in a 250 mL Erlenmeyer flask containing 50 mL of sterile, semidefined proteose – peptone – based medium and five different conc. of test substance. Then the flasks were inoculated with log-growth-phase culture of Tetrahymena pyriformis and incubated for about 40 hrs at 27 ± 1ᵒC with pH 7.4. After incubation, growth inhibition was measured spectrophotometrically or by electronic particle counting and 50% effect levels are determined at 72 hrs.

- Preparation of inoculum for exposure: No data available

- Pretreatment: No data available

- Initial biomass concentration: No data available

Test type:

static

Water media type:

not specified

Limit test:

no

Total exposure duration:

40 h

Remarks on exposure duration:

No data

Post exposure observation period:

No data

Hardness:

No data

Test temperature:

27 ± 1ᵒC

pH:

7.4

Dissolved oxygen:

No data available

Salinity:

No data available

Conductivity:

No data available

Nominal and measured concentrations:

Nominal

Details on test conditions:

TEST SYSTEM
- Test vessel: Erlenmeyer flask
- Type (delete if not applicable): No data available
- Material, size, headspace, fill volume: 250 ml Erlenmeyer flask filled with 50 ml of solution having the headspace of 200 ml.
- Aeration: No data
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 2
- No. of vessels per vehicle control (replicates): 2
- No. of vessels per abiotic control (replicates): No data available
- Sludge concentration (weight of dry solids per volume): Initial density of cell varied from 1000 to 5000 cells/mL, but for the study approx. 2500 cells/mL (i.e., 0.20 mL of 48-h culture) was used.
- Weight of dry solids per volume of reaction mixture per unit of time: No data available
- Nutrients provided for bacteria: No data available
- Nitrification inhibitor used (delete if not applicable): none / N-allylthiourea: No data available
- Biomass loading rate: No data available

TEST MEDIUM / WATER PARAMETERS : No data available
- Source/preparation of dilution water:
- Particulate matter:

OTHER TEST CONDITIONS
- Adjustment of pH: Yes
- Photoperiod:
- Light intensity:
- Details on termination of incubation:

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
TEST CONCENTRATIONS: Growth inhibition was measured spectrophotometrically or by electronic particle counting. Because of the ease and speed, the spectrophotometric method was the method used for the test. However, electronic counting method can also be employed for the study. In spectrophotometric analysis, population growth impairment was monitored as absorbance at 540 nm.

- Spacing factor for test concentrations:
- Justification for using fewer concentrations than requested by guideline: No data
- Range finding study: Range finding assay was designed to allow accurate approximation of both the highest conc. with no observed effect on population growth and the lowest conc. with total inhibition of cell replication.
- Test concentrations: Five different test substance conc. was used for the study, but exact conc. was not reported.
- Results used to determine the conditions for the definitive study: No data

Reference substance (positive control):

not specified

Key result

Duration:

40 h

Dose descriptor:

other: Inhibitory Growth Concentration(IGC50)

Effect conc.:

0.013 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth inhibition

Remarks on result:

other: For Log IGC50-1 value was 1.90 mg/l

Details on results:

No data available

Results with reference substance (positive control):

No data available

Reported statistics and error estimates:

The 50% inhibitory growth concentration in mg/l (IGC50) and the 95% fiducial interval are determined for each test compound. The IGC50 was calculated with theprobit procedure using the percent control – normalized absorbance as the dependent variable and the toxicant concentration in mg/l as the independent variable.

These values have been computed with Statistical Analysis System (SAS) software. Both the slope and the intercept of the probit regression equation are recorded as well as the chi – squared value.

Validity criteria fulfilled:

not specified

Conclusions:

Based on growth inhibition of test organism, the IGC50 value was 0.0125 mg/l. (For Log IGC50-1 value was 1.90 mg/l).

Executive summary:

Toxicity to micro-organisms study was conducted on Tetrahymena pyriformis strain GL for 40 hrs. The assay was conducted in a buffered medium under static conditions.

 

Stock solutions of test chemical was prepared either in solvent DMSO or in distilled water.The solvent DMSO has low toxicity toTetrahymena,low volatility, and high ability to dissolve organic chemicals. Concentration not greater than 0.75% DMSO (350 µL per 50 mL of medium) are used. This conc. was shown to have no effect onTetrahymenapopulation growth. Standard stocks are prepared on a milligram per liter basis. When using distilled water for prepare stock solutions, extra care must be taken to maintain sterility.

 

Tests were conducted in a 250 mL Erlenmeyer flask containing 50 mL of sterile, semidefined proteose – peptone – based medium and five different conc. of test substance. Then the flasks were inoculated with log-growth-phase culture ofTetrahymena pyriformisof initial cell density of approx. 2500 cells/ml and incubated for about 40 hrs at27 ± 1ᵒC with pH 7.4. After incubation, growth inhibition was measured spectrophotometrically or by electronic particle counting and 50% effect levels are determined at 72 hrs.

 

The nutritional requirement of test organism was met by a solution of proteaose-peptone, yeast extract, glucose, and Fe-EDTA. For test bacterial strain, the optimum temperature for growth was in between 27ᵒC and 35ᵒC and pH range is 5.0 – 8.6, with the optimum pH being 7.5, respectively.

 

Control test vessel contains the test medium inoculated with the test organism with no addition of test chemical and blank was also prepared for the study. The 50% inhibitory growth concentration in mg/l (IGC50) and the 95% fiducial interval are determined for each test compound. The IGC50 was calculated with the probit procedure. Thus, based on growth inhibition of test organism, the IGC50 value was 0.0125 mg/l. (For Log IGC50-1 value was 1.90 mg/l).

Description of key information

Toxicity to micro-organisms study was conducted onTetrahymena pyriformisstrain GL for 40 hrs. The assay was conducted in a buffered medium under static conditions.

 

Stock solutions of test chemical was prepared either in solvent DMSO or in distilled water.The solvent DMSO has low toxicity toTetrahymena,low volatility, and high ability to dissolve organic chemicals. Concentration not greater than 0.75% DMSO (350 µL per 50 mL of medium) are used. This conc. was shown to have no effect onTetrahymenapopulation growth. Standard stocks are prepared on a milligram per liter basis. When using distilled water for prepare stock solutions, extra care must be taken to maintain sterility.

 

Tests were conducted in a 250 mL Erlenmeyer flask containing 50 mL of sterile, semidefined proteose – peptone – based medium and five different conc. of test substance. Then the flasks were inoculated with log-growth-phase culture ofTetrahymena pyriformisof initial cell density of approx. 2500 cells/ml and incubated for about 40 hrs at27 ± 1ᵒC with pH 7.4. After incubation, growth inhibition was measured spectrophotometrically or by electronic particle counting and 50% effect levels are determined at 72 hrs.

 

The nutritional requirement of test organism was met by a solution of proteaose-peptone, yeast extract, glucose, and Fe-EDTA. For test bacterial strain, the optimum temperature for growth was in between 27ᵒC and 35ᵒC and pH range is 5.0 – 8.6, with the optimum pH being 7.5, respectively.

 

Control test vessel contains the test medium inoculated with the test organism with no addition of test chemical and blank was also prepared for the study. The 50% inhibitory growth concentration in mg/l (IGC50) and the 95% fiducial interval are determined for each test compound. The IGC50 was calculated with the probit procedure. Thus, based on growth inhibition of test organism, the IGC50 value was 0.0125 mg/l. (For Log IGC50-1 value was 1.90 mg/l).

Key value for chemical safety assessment

EC50 for microorganisms:

0.013 mg/L

Additional information

In the first experimental study for target chemical toxicity was determine on Tetrahymena. Toxicity to micro-organisms study was conducted onTetrahymena pyriformis strain GL for 40 hrs. The assay was conducted in a buffered medium under static conditions. Stock solutions of test chemical was prepared either in solvent DMSO or in distilled water.The solvent DMSO has low toxicity toTetrahymena, low volatility, and high ability to dissolve organic chemicals. Concentration not greater than 0.75% DMSO (350 µL per 50 mL of medium) are used. This conc. was shown to have no effect onTetrahymena population growth. Standard stocks are prepared on a milligram per liter basis. When using distilled water for prepare stock solutions, extra care must be taken to maintain sterility. Tests were conducted in a 250 mL Erlenmeyer flask containing 50 mL of sterile, semidefined proteose – peptone – based medium and five different conc. of test substance. Then the flasks were inoculated with log-growth-phase culture ofTetrahymena pyriformis of initial cell density of approx. 2500 cells/ml and incubated for about 40 hrs at 27 ± 1ᵒC with pH 7.4. After incubation, growth inhibition was measured spectrophotometrically or by electronic particle counting and 50% effect levels are determined at 72 hrs. The nutritional requirement of test organism was met by a solution of proteaose-peptone, yeast extract, glucose, and Fe-EDTA. For test bacterial strain, the optimum temperature for growth was in between 27ᵒC and 35ᵒC and pH range is 5.0 – 8.6, with the optimum pH being 7.5, respectively. Control test vessel contains the test medium inoculated with the test organism with no addition of test chemical and blank was also prepared for the study. The 50% inhibitory growth concentration in mg/l (IGC50) and the 95% fiducial interval are determined for each test compound. The IGC50 was calculated with the probit procedure. Thus, based on growth inhibition of test organism, the IGC50 value was 0.0125 mg/l. (For Log IGC50-1 value was 1.90 mg/l).

Similarly in the second supporting study for the RA CAS 4-Chlorobenzonitrile (623-03-0) from ecotox database 2017, Toxicity of 4-Chlorobenzonitrile to micro-organisms study was conducted onTetrahymena pyriformis for 2 days. Test performed in static system.Based on Population growth rate inhibition of test organism, the IC50 value was 95.5 mg/l. with 95% confidence interval of 95280 (16872-137470) ug/L.