Hexylamine

Toxicity to microorganisms

Link to relevant study record(s)

Reference

Endpoint:

toxicity to microorganisms

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Data is from peer reviewed journal

Justification for type of information:

Data is from peer reviewed journal

Qualifier:

according to guideline

Guideline:

other: refer below principle

Principles of method if other than guideline:

The assay is a short-term, static protocol using the common freshwater ciliate Tetrahymena pyriformis (strain GL-C). The 50% impairment growth concentration (IGC50) is the recorded endpoint.

GLP compliance:

not specified

Analytical monitoring:

not specified

Details on sampling:

No data

Vehicle:

yes

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Chemical name of vehicle (organic solvent, emulsifier or dispersant):Yes, dimethyl sulfoxide (DMSO)
- Concentration of vehicle in test medium (stock solution and final test solution(s) including control(s)):Concentrations no greater than 0.755 DMSO (37.5ml per 50ml of medium) are used.

Test organisms (species):

Tetrahymena pyriformis

Test type:

static

Water media type:

freshwater

Total exposure duration:

40 h

Hardness:

No data

Test temperature:

between 27 and 35°C

pH:

between 5.0 and 8.6, with the optimum being 7.35

Dissolved oxygen:

No data

Salinity:

No data

Nominal and measured concentrations:

measured

Details on test conditions:

Test vessel: Erlenmeyer flasks.
Type (delete if not applicable): open / closed: closed
Material, size, headspace, fill volume:50 ml of a semi-defined medium in 250 ml Erlenmeyer flasks
No. of organisms per vessel: Experimental cultures begin with 1000 to 2500 cells /ml
No. of vessels per control (replicates):8 to 9 divisions .

TEST CONCENTRATIONS
Range finding study: Each chemical is definitively evaluated at least three times using freshly prepared stock solutions Each definitive set is set in duplicates and consists of 6-step (counting controls) graded concentration series.
Results used to determine the conditions for the definitive study: In the TETRATOX assay, a range-finding assay followed by three replicate definitive tests is performed on each test material. Definitive test replicates consist of a minimum of five different concentrations of each test material with duplicate flasks of each concentration. each analysis. Duplicate controls, which have no test material but were inoculated with T. pyriformis, and a blank are used to provide a measure of the acceptability of the test by indicating the suitability of the medium and test conditions, and a basis for interpreting data from other treatments. Duplicate flasks are inoculated with an initial density of ≈2,500 cells/ml with log-growth-phase ciliates. Following ≈40 hours of incubation at 27 ± 1°C, population density is measured spectrophotometrically and 50% effect levels determined.

Reference substance (positive control):

not specified

Duration:

40 h

Dose descriptor:

other: IGC50

Effect conc.:

1.659 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

growth inhibition

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 is calculated by probit analysis using the percent control-normalized absorbance as the dependent variable and the toxicant concentration in mg/l as the independent variable.

Amine	log(IGC50)^-1 mM	IGC50 mg/l
Hexylamine	-0.22	1.6595

Validity criteria fulfilled:

not specified

Conclusions:

The Tetratox assay is a short-term, static protocol using the common freshwater ciliate Tetrahymena pyriformis (strain GL-C). The 50% impairment growth concentration (IGC50) is the recorded endpoint.
The 50% Impairment(Inhibitory ) Growth Concentration IGC50 for hexylamine is estimated to be 1.6595mg/lt. It is reported to be bioreactive.

Executive summary:

The Tetratox assay is a short-term, static protocol using the common freshwater ciliate Tetrahymena pyriformis (strain GL-C). The 50% impairment growth concentration (IGC₅₀) is the recorded endpoint.   Cultures are reared in 50 ml of a semi-defined medium in 250 ml Erlenmeyer flasks. In the TETRATOX assay, a range-finding assay followed by three replicate definitive tests is performed on each test material.

Definitive test replicates consist of a minimum of five different concentrations of each test material with duplicate flasks of each concentration. . Duplicate controls, which have no test material but were inoculated with T. pyriformis, and a blank are used to provide a measure of the acceptability of the test by indicating the suitability of the medium and test conditions, and a basis for interpreting data from other treatments. Duplicate flasks are inoculated with an initial density of ≈2,500 cells/ml with log-growth-phase ciliates. Following ≈40 hours of incubation at 27 ± 1°C, population density is measured spectrophotometrically and 50% effect levels determined. The 50% inhibitory growth concentration in mg/l (IGC₅₀) and the 95% fiducial interval are determined for each test compound.

The IGC₅₀ is calculated by probit analysis using the percent control-normalized absorbance as the dependent variable and the toxicant concentration in mg/l as the independent variable   The 50% Impairment(Inhibitory ) Growth Concentration IGC50 for hexylamine is estimated to be 1.6595mg/lt. It is reported to be bioreactive.

Description of key information

In the first Tetratox assay is a short-term, static protocol using the common freshwater ciliate Tetrahymena pyriformis (strain GL-C). The 50% impairment growth concentration (IGC50) is the recorded endpoint.   Cultures are reared in 50 ml of a semi-defined medium in 250 ml Erlenmeyer flasks. In the TETRATOX assay, a range-finding assay followed by three replicate definitive tests is performed on each test material. Definitive test replicates consist of a minimum of five different concentrations of each test material with duplicate flasks of each concentration. . Duplicate controls, which have no test material but were inoculated with T. pyriformis, and a blank are used to provide a measure of the acceptability of the test by indicating the suitability of the medium and test conditions, and a basis for interpreting data from other treatments. Duplicate flasks are inoculated with an initial density of ≈2,500 cells/ml with log-growth-phase ciliates. Following ≈40 hours of incubation at 27 ± 1°C, population density is measured spectrophotometrically and 50% effect levels determined. The 50% inhibitory growth concentration in mg/l (IGC50) and the 95% fiducial interval are determined for each test compound. The IGC50 is calculated by probit analysis using the percent control-normalized absorbance as the dependent variable and the toxicant concentration in mg/l as the independent variable   The 50% Impairment(Inhibitory ) Growth Concentration IGC50 for hexylamine is estimated to be 1.6595mg/lt. It is reported to be bioreactive.

Key value for chemical safety assessment

EC50 for microorganisms:

1.659 mg/L

Additional information

Various short term studies available for the test chemical n- hexylamine (CAS 111-26-2) were reviewed to determine the toxic nature of test chemical on the growth of microorganism. The studies are as mentioned below:

 

In the first Tetratox assay is a short-term, static protocol using the common freshwater ciliate Tetrahymena pyriformis (strain GL-C). The 50% impairment growth concentration (IGC50) is the recorded endpoint.   Cultures are reared in 50 ml of a semi-defined medium in 250 ml Erlenmeyer flasks. In the TETRATOX assay, a range-finding assay followed by three replicate definitive tests is performed on each test material. Definitive test replicates consist of a minimum of five different concentrations of each test material with duplicate flasks of each concentration. . Duplicate controls, which have no test material but were inoculated with T. pyriformis, and a blank are used to provide a measure of the acceptability of the test by indicating the suitability of the medium and test conditions, and a basis for interpreting data from other treatments. Duplicate flasks are inoculated with an initial density of ≈2,500 cells/ml with log-growth-phase ciliates. Following ≈40 hours of incubation at 27 ± 1°C, population density is measured spectrophotometrically and 50% effect levels determined. The 50% inhibitory growth concentration in mg/l (IGC50) and the 95% fiducial interval are determined for each test compound. The IGC50 is calculated by probit analysis using the percent control-normalized absorbance as the dependent variable and the toxicant concentration in mg/l as the independent variable   The 50% Impairment(Inhibitory ) Growth Concentration IGC50 for hexylamine is estimated to be 1.6595mg/lt. It is reported to be bioreactive.

 

Above study was also supported by the second study. The comparatively quick and low cost bioassay with Photobacterium phosphoreum, strain NRRL-B-11177 (Microtox3), occasionally also referred to as Vibrio fischerii, strain NRRL-B-11177 was used to assess the toxicity of hexylamine to aquatic bacteria. The luminescent bacterial bioassay requires only a short period of time, i.e. minutes. In terms of testing a broad range of different chemicals with many different modes of action, a somewhat longer assay time, i.e. 30 min, is preferred, mainly to ascertain that potential diffusion problems are eliminated at source. Normally the pT values for a particular chemical rarely vary much with exposure time. The most commonly used operating conditions are 15°C for the EC50tests with exposure times of 5 to 30 min. The pH of the test system can vary in the range of 5< pH <9 without great effect on the luminescence. The Effective Concentration causing 50% mortality of luminescent bacteria Photobacteria phosphereum was found to be 14 mg/l after 30 minutes exposure to hexylamine.

 

The solvation parameter model to construct models for estimating the non-specific toxicity of neutral organic compounds to the photo bacterium Vibrio fischeri, the bacterium Pseudomonas putida, the protozoan Tetrahymena pyriformis, the green alga Scendesmus quadricaudaand the brine shrimp Artemia salina. The solvation parameter model is based on a cavity model of solvation. Transfer of a solute from the donor to the acceptor phase requires creation of a cavity in the acceptor phase for the solute, an energetically unfavorable process that is opposed by solvent–solvent interactions. According to the study the excess toxicity (IGC50) for hexylamine is 0.63