Methyltrioctylammonium chloride

Toxicity to aquatic algae and cyanobacteria

Link to relevant study record(s)

Reference

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

25.05.2018 to 28.05.2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

Experimental test result performed using standard test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Principles of method if other than guideline:

Aim of this study was to evaluate the nature of chemical when comes in contact with the test organism. Test was conducted according to the OECD guideline 201.

GLP compliance:

not specified

Specific details on test material used for the study:

- Name of test material (IUPAC name): Methyltrioctylammonium chloride
- Molecular formula: C25H54ClN
- Molecular weight: 404.162 g/mole
- Smiles :[N+](CCCCCCCC)(CCCCCCCC)(CCCCCCCC)C.[ClH-]
- Inchl: 1S/C25H54N.ClH/c1-5-8-11-14-17-20-23-26(4,24-21-18-15-12-9-6-2)25-22-19-16-13-10-7-3;/h5-25H2,1-4H3;1H/q+1;/p-1
- Substance type: Organic
- Physical state: Viscous liquid (colorless to yellow)

Analytical monitoring:

not specified

Vehicle:

not specified

Details on test solutions:

The stock solution 100 mg/l was prepared by dissolving colourless dense liquid in OECD growth medium. Test solutions of required concentrationas were prepared by mixing the stock solution of the test sample with OECD growth medium and inoculum culture.

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Details on test organisms:

TEST ORGANISM
- Common name:
- Strain: 86.81 SAG
- Source (laboratory, culture collection): Institute of botany of the ASCR
- Initial biomass concentration: 5x10(3) cells /ml
- Method of cultivation: No data available

ACCLIMATION - No data available
- Acclimation period:
- Culturing media and conditions (same as test or not):
- Any deformed or abnormal cells observed:

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Test temperature:

23±2°C

pH:

Test at highest concentration 0.80 mg/l: 8 changes to 7.6 during test
Control: 8 changes to 7.6

Nominal and measured concentrations:

0, 0.05, 0.10, 0.20, 0.40, 0.80 mg/l

Details on test conditions:

TEST SYSTEM
- Test vessel: 50 ml Glass vessel
- Type (delete if not applicable): closed (with air permeable stopper)
- Sample volume: 15 ml
- Initial cells density: 5x10(3) cells/ml
- No. of vessels per concentration (replicates): 3

GROWTH MEDIUM
- Standard medium used: yes

OTHER TEST CONDITIONS
- Adjustment of pH: No
- Photoperiod: Continuous
- Light intensity and quality: 6000-8000 lx

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Determination of cell concentrations: microscope with counting chamber Cyrus I or electronic particle counter.
- Other: ErC50 was calculated using non-linear regression by the software Prism 4.0

Reference substance (positive control):

yes

Remarks:

Potassium dichromate (K2Cr2O7)

Key result

Duration:

72 h

Dose descriptor:

other: ErC50

Effect conc.:

0.56 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: 95 % CI was 0.44 - 0.71 mg/l

Results with reference substance (positive control):

- Results with reference substance valid
- ErC50: 0.77 mg/L (24 hours)

Reported statistics and error estimates:

ErC50 was calculated using non linear regression by the software Prism 4.0

Validity criteria fulfilled:

yes

Conclusions:

Based on the growth rate inhibition of algae Desmodesmus subspicatus (previous name: Scenedesmus subspicatus) due to the exposure of chemical the ErC50 was determine to be 0.56 mg/l.

Executive summary:

Aim of this study was to evaluate the nature of chemical test chemical Methyltrioctylammonium chloride when comes in contact with the test organism Desmodesmus subspicatus (previous name: Scenedesmus subspicatus). Test was conducted according to the OECD guideline 201. The stock solution 100 mg/l was prepared by dissolving colourless dense liquid in OECD growth medium. Test solutions of required concentrationas were prepared by mixing the stock solution of the test sample with OECD growth medium and inoculum culture. Various concentrations 0, 0.05, 0.10, 0.20, 0.40, 0.80 mg/l were used.

With the test substance one positive control Potassium dichromate (K2Cr2O7) was also run simultaneously. After the exposure of chemical, effect concentration EC50 was calculated using nonlinear regression by the software Prism 4.0. Effect on the growth of algae was determine after an exposure period of 72 hrs.

The median effective concentration (EC50) for the test substance Methyltrioctylammonium chloride, in algae was determined to be 0.56 mg/L on the basis of growth rate inhibition effects in a 72 hour study. Thus based on the EC50 value, it indicates that the substance is likely to be hazardous to aquatic algae and can be consider to be classified as aquatic acute1 category as per the CLP classification criteria.

Description of key information

Aim of this study was to evaluate the nature of chemical test chemical Methyltrioctylammonium chloride when comes in contact with the test organism Desmodesmus subspicatus (previous name: Scenedesmus subspicatus). Test was conducted according to the OECD guideline 201. The stock solution 100 mg/l was prepared by dissolving colourless dense liquid in OECD growth medium. Test solutions of required concentrationas were prepared by mixing the stock solution of the test sample with OECD growth medium and inoculum culture. Various concentrations 0, 0.05, 0.10, 0.20, 0.40, 0.80 mg/l were used. With the test substance one positive control Potassium dichromate (K2Cr2O7) was also run simultaneously. After the exposure of chemical, effect concentration EC50 was calculated using nonlinear regression by the software Prism 4.0. Effect on the growth of algae was determine after an exposure period of 72 hrs. The median effective concentration (EC50) for the test substance Methyltrioctylammonium chloride, in algae was determined to be 0.56 mg/L on the basis of growth rate inhibition effects in a 72 hour study. Thus based on the EC50 value, it indicates that the substance is likely to be hazardous to aquatic algae and can be consider to be classified as aquatic acute1 / chronic 2 category as per the CLP classification criteria.

Key value for chemical safety assessment

EC50 for freshwater algae:

0.56 mg/L

Additional information

Based on the various experimental data for the target chemical study have been reviewed to determine toxic nature of Methyltrioctylammonium chloride

(CAS N O. 5137-55-3) on the growth and other activity of algae. The studies are as mentioned below:

The first key study is from experimental report 2018. Aim of this study was to evaluate the nature of chemical test chemical Methyltrioctylammonium chloride when comes in contact with the test organism Desmodesmus subspicatus (previous name: Scenedesmus subspicatus). Test was conducted according to the OECD guideline 201. The stock solution 100 mg/l was prepared by dissolving colourless dense liquid in OECD growth medium. Test solutions of required concentrationas were prepared by mixing the stock solution of the test sample with OECD growth medium and inoculum culture. Various concentrations 0, 0.05, 0.10, 0.20, 0.40, 0.80 mg/l were used. With the test substance one positive control Potassium dichromate (K2Cr2O7) was also run simultaneously. After the exposure of chemical, effect concentration EC50 was calculated using nonlinear regression by the software Prism 4.0. Effect on the growth of algae was determine after an exposure period of 72 hrs. The median effective concentration (EC50) for the test substance Methyltrioctylammonium chloride, in algae was determined to be 0.56 mg/L on the basis of growth rate inhibition effects in a 72 hour study. Thus based on the EC50 value, it indicates that the substance is likely to be hazardous to aquatic algae and can be consider to be classified as aquatic acute1 / chronic 2 category as per the CLP classification criteria.

First study was supported by the second study from experimental data from peer reviewed journal. Aim of this study was to determine the long term effect of test chemical Methyltrioctylammonium chloride on thirteen freshwater algal species grown in 250-µl liquid cultures on plastic microtitration plates. Test conducted for 14 days. Stock solutions of the chemicals in sterile distilled water were freshly prepared under aseptic conditions prior to each experiment. pH was adjusted to 6.5-7.5 using HCl or NaOH. Whenever a cosolvent (ethanol) was used, the final concentration never exceeded 0.2%. 13 algal species were used on which effect were measured was Chlamydomonas dysosmos, Chlorella emersonii, Kirchneriella contorta, Monoraphidium pusillum, Scenedesmus obtusiusculus, Selenastrum capricornutum, Klebsormidium marinum, Raphidonema longiseta, Bumilleriopsis filiformis, Monodus subterraneus, Tribonema aequale, Oscillatoriales LPP species, Synechococcus leopoliensis. Axenic strains of 13 algal species were kept on agar slants. Precultures were grown in an inorganic medium, Z8 modified by the addition of Si (0.16 mM) and vitamins (thiamine, 200 µg/liter; biotin, 1 µg/liter; B12, 1 µg/liter). Cultures were continuously illuminated by Cool White fluorescent tubes (General Electric F96 PG 17CWX Power Groove de Luxe) at an irradiance of 10 ± 1 W/m2 at 400-700 nm. The temperature was 20 ± 1°C. Log phase cells were used as inoculum for the growth experiments. Prior to inoculation of the test cultures the precultures were tested for bacterial contamination by streaking onto agar plates. 250 µl Microtitration plate filled with 100 µl and 150 µl of algal cells were use. The resulting geometric concentration series (factor 0.5) covered 4.2 orders of magnitude (14 concentrations on two plates). Based on the complete algal growth inhibition by the test chemical Methyltrioctylammonium chloride in the exposure period of 14 days, the EC100 was observed at 0.5 mg/l and toxicity values ranges from 0.25 – 1 mg/l. Based on the EC100, chemical consider to be toxic and can be consider to be classified as aquatic chronic 2 as per the CLP classification criteria.

Similarly in the third study the toxicity of test material [4-[[4-(diethylamino)phenyl]phenylmethylene]-2,5-cyclohexadien-1-ylidene]diethylammonium acetate on the growth of Chlorella emersonii (strain 21 1/8h) was evalauted . An artificial medium was used at a 25 % dilution for the growth medium. Air was passed through the cultures at a rate of 10 dm³/ h. The cultures were continuously illuminated with cool white fluorescent tubes, giving a light intensity at the front surface of the culture tubes of 10 W m^{-2 .}Growth was followed by measuring absorbance at 540 nm and growth curves were constructed by plotting the logarithm of the absorbance against time. The inoculum was adjusted to give an initial cell concentration corresponding to a chlorophyll concentration of 0.16 µg cm^-3. The exponential growth rate was determined from the linear part of the growth curves by means of linear regression analysis. The effect of test material was observed for exponential growth curve as well as biomass. The effect concentration (EC50) for Exponential growth rate was observed to be in the range 0.5 - 1.0 mg/l and for biomass EC50 was observed to be 0.1 - 0.5 mg/l. Thus, Based on the above effect concentration it was considered that the test material is toxic to aquatic algae and cyanobacteria and can be classified as aquatic acute 1 as per CLP criteria.

Thus based on the overall studies from experimental report and peer reviewed journal, chemical consider to be toxic and can be consider to be classified as aquatic acute 1/ chronic 2 as per the CLP classification criteria.