Betaine hydrochloride

Toxicity to aquatic algae and cyanobacteria

Administrative data

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Study initiation date: March 29th, 2010. Experimental starting date: April 6th, 2010. Experimental completion date: April 9th, 2010. Study completion date: April 20th, 2010.

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

The study was conducted in compliance with Principles of Good Laboratory Practice. The study was carried out according to OECD guideline method 201. This study was selected as the key study because the information provided for the hazard endpoint is sufficient for the purpose of classification and labelling and/or risk assessment.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Report date:

2010

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Deviations:

yes

Remarks:

All validity criteria except one was fulfilled. The mean coefficient of variation for section -by-section specific rates in the control cultures was 65 % exceeding the validation criteria (limit < 35 %).

GLP compliance:

yes

Remarks:

SNAS Reg. No. 049/G-020

Test material

Test material information

Constituent 1

Reference substance name:

Betaine

EC Number:

203-490-6

EC Name:

Betaine

Cas Number:

107-43-7

Molecular formula:

C5H11NO2

IUPAC Name:

(trimethylammonio)acetate

Details on test material:

Tradename BETAFIN BP20. Batch number: 4311280004. Material: C11A0. Data of production: 15.10.2009. Purity: 99.6%.

Sampling and analysis

Analytical monitoring:

yes

Test organisms

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Details on test organisms:

SAG Strain Number: 86.81. Source: Jan Futak Botanical Association, Bratislava. Received in the laboratory: 29.01.2010. Storage: a glass tube with slant agar alga culture stored in refrigerator at 5 C+/- 1 C.

Study design

Test type:

static

Water media type:

freshwater

Total exposure duration:

72 h

Test conditions

Test temperature:

Test was performed in the air-conditioned chamber with an automatic regulation and temperature monitoring. Average temperature in the chamber during the test was 23.6 C.

pH:

The Initial pH and the pH after 72 hours were measured in the controls and each test solutions during the test. The pH in the control varied between 8.00 to 9.31, and between 7.87 to 9.23 in the test solutions.

Nominal and measured concentrations:

The definitive test was performed with these nominal concentrations of the test substance: 0 mg/l, 312,5 mg/l, 625 mg/l, 1250 mg/l, 2500 mg/l, 5000 mg/l. Based on the preliminary test results on stability of the test substance, this substance was stable in the test media during 72 hours. Concentration of TOC (%) remained within 80-120 % of nominal concentration after 72 hours stability test. Therefore, no calculation adjustment of concentrations was needed in the proper test.

Details on test conditions:

Test media was prepared in accordance with SOP D28 365 A, and in compliance with OECD guideline. After preparation of alga pre-culture and stockculture, the initial biomass of the alga culture was 5000 cells/l in control and test solutions. Each test solution was prepared to the total test volume of 300 ml, containing 30 ml of alga stock solution and remaining volume of growth media. This total volume was distributed into 3 parallels. Control solution was prepared to the total test volume of 600 ml consisting of 540 ml of growth media and 60 ml of stock alga culture. This total volume was distributed into 6 parallels.

The inhibition of growth was used as an endpoint measurement expressed as the logarithmic increase in biomass. The specified growth rate inhibition was determined, and the results were expressed as EC10 and EC50-values. In addition, the NOEC-value was determined from the EC10-values.

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

<= 120.2 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: 95 % confidence interval: 84.7-158.4 mg/l

Effect concentrations 2

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

<= 1 199 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: 95 % confidence interval: 1078.7-1331.2 mg/l

Effect concentrations 3

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

<= 312.5 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Results with reference substance (positive control):

Potassium dichromate was used as a reference substance. 72 hour EC50-value for potassium dichromate was 0.96 mg/l, and the result was within the range specified in ISO 8692 (0.6-1.08 mg/l).

Reported statistics and error estimates:

All effective concentrations were calculated using TOXEDO v.1.2 software. Confidence intervals (95 %) were determined for the EC-values. The NOEC-values were calculated using sofware Dunnet v 1.5.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Remarks:

All validity criteria expect one was fulfilled. The mean coefficient of variation for section -by-section specific rates in the control cultures was 65 % exceeding the validation criteria (limit < 35 %).

Conclusions:

The toxicity study of the test substance (Betafin BP20) on algae was conducted in compliance with Principles of Good Laboratory Practice. The study was carried out according to OECD guideline method 201. The inhibition of growth was used as an endpoint measurement expressed as the logarithmic increase in biomass. The specified growth rate inhibitions after 72 hours exposure were determined and toxicity was expressed as the EC10- and EC50-values.The EC10-value of the test substance was 120.2 mg/l with confidence interval of 84.7-158.4 mg/l. The EC50-value was 1199 mg/l with confidence interval of 1078.7-1331.2 mg/l. The NOEC-value of the test substance was < 312.5 mg/l after 72 hour exposure.

This study and the conclusions which are drawn from it fulfil the quality criteria (validity, reliability, repeatability).

Executive summary:

The toxicity study of the test substance (Betafin BP20) on algae was conducted in compliance with Principles of Good Laboratory Practice. The study was carried out according to OECD guideline method 201. The inhibition of growth was used as an endpoint measurement expressed as the logarithmic increase in biomass. The specified growth rate inhibitions after 72 hours exposure were determined and toxicity was expressed as the EC₁₀- and EC₅₀-values.The EC₁₀-value of the test substance was 120.2 mg/L with confidence interval of 84.7-158.4 mg/L. The EC₅₀-value was 1199 mg/L with confidence interval of 1078.7-1331.2 mg/L. The NOEC-value of the test substance was < 312.5 mg/L after 72 hour exposure.