Dodecyltrimethylammonium 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:

10/24 - 10/27/1988

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Deviations:

no

GLP compliance:

yes

Specific details on test material used for the study:

% active substance : 35.2

Analytical monitoring:

yes

Details on sampling:

Duration : 72 hours
Test Containers : 200 mL borosilicaye glass erlenmeyers covered with cotton wool
Replicates and control : The test includes six controls containing only algal medium and three replicates at each test concentration.

Vehicle:

no

Details on test solutions:

Sotck solution of the test substance: A stock solution of 995 mg/L (based on the active component) is prepared by dissolving 565.3 mg of the test substance in 200 mL deionised water.

Test concentrations: the following test concentrations - made up in a geometric series at a concentration ratio of 2.0 - are prepared by appropriate dilution of the stock solution with algal medium: 0 (control) - 0.005 - 0.010 - 0.020 - 0.040 - 0.080 - 0.160 and 0.319 mg/L (nominal concentration based on the active component).

Volume of test solution: 100 mL of test solution in each erlenmeyer.

Light intensity: Continious uniform illumination is provided by Philips TL-33 lamps yielding 4200 Lux at the surface of the test solution as measured with a spherical collector.

Temperature: the temperature og the test solutions is maintained at 23.0 +/- 1.2 °C over the 72-hours test period.

Adjustment of pH: Adjustment of the pH of the test solutions before inoculation is not necessary.

Test organisms (species):

Selenastrum sp.

Details on test organisms:

Species: Selenastrum capricornutum

Method of cultivation: the culturing of Selenastrum capricornutum for use in the alga growth inhibition test is carried out according to the procedure outlined in the Annex of OECD Guideline 201. The pre-culture of Selenastrum capricornutum which is used for the inoculation of the test cultures is incubated under the conditions of the test. After an incubation period of 5 days, the cell density of the pre-culture is 2.0x10E6 cells/mL. Microscopic observation reveals that the pre-culture contains no deformed or abnormal algal cells.

Initial cell concentration: the initial cell concentration of Selenastrum caprucornutum in the test cultures is 1.0x10E4 cells/mL.

Shaking: In order to keep the algae in suspension and to facilitate transfer of CO2, the test erlenmeyer are shaken manually three times per day.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Test temperature:

The temperature is maintained in the range 21 to 25 °C, controlled at +/- 2 °C.

pH:

The pH of each solution is measured at the beginning and at the end of the test; the pH of the test solutions should not change by more than one pH unit during the test. If pH of the test solution is lower than controls, adjust to pH of control at start.

Nominal and measured concentrations:

Nominal concentrations based on the active component : 0 (control) - 0.005 - 0.010 - 0.020 - 0.040 - 0.080 - 0.160 and 0.319 mg/L

measured concentrations: "According to the sponsor's regulations, the actual concentrations of the test substance in the test solutions have not been determined. Therefore, all results are based on added (nominal) concentrations.

Details on test conditions:

N° of organisms per vessels : 1 000 cells per mL
N° of vessels per concentrations (replicate): three replicates at each test concentration.
N° of vessels per control: 6 controls containing only algal medium
photoperiod: continious uniform illumination
Source/preparation of dilution water: prepared as described in OECD 201 test Guideline.

Reference substance (positive control):

no

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

ca. 0.036 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Key result

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

ca. 0.01 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Details on results:

See table below in the section: "Any other information on results incl. tables"

Reported statistics and error estimates:

See table below in the section: "Any other information on results incl. tables"

Details on results:

Table: Toxicity of E-3467.01 to Selenastrum

Concentration	Area	Inhibition (%)	Average growth rate (/h)	Inhibition
Control 0.005 mg/L 0.010 mg/L 0.020 mg/L 0.040 mg/L 0.080 mg/L 0.160 mg/L 0.319 mg/L	11.19 10.84 10.44 8.39 4.76 1.79 0.61 0.30	3.1 6.7 25.0 57.4 84.0 94.6 97.4	0.0575 0.0533 0.0530 0.0532 0.0436 0.0176 0.0041 0.0059	7.3 7.8 7.5 24.1 69.4 92.9 89.8

 

reported statistics and error estimates:

Table: Toxicity of E-3467.01 to Selenastrum

Parameter	Biomass	Growth rate
EC50 (mg/L) m R Y-int	0.036 1.80 +/- 0.07 0.9965 2.60 +/- 0.10	0.058 2.48 +/- 0.12 0.9976 3.07 +/- 0.15

m: slope of the concentration-effect curve

y-int: y-intercept

R: lincar regression coefficient of the concentration-effect curve.

+/- S.E.: +/- estimated standard error

Validity criteria fulfilled:

yes

Conclusions:

The concentrations of E-3467.01 which cause 50% inhibition of growth (EbC50, 0 -72h) and of growth rate (ErC50, 24 -72h) of the green alga Selenastrum capricornutum with respect to a control culture are 0.036 and 0.058 mg/L respectively (nominal concentrations based on the active component).
A concentration of 0.010 mg/L (NOEC) does not inhibit the growth of Selenastrum capricornutum.

Executive summary:

Objective:

The purpose of this test is to determine the effects of a test substance on the growth of a unicellular green algal species.

Test substance:

Dodecylmethlammonium chloride (CAS N° 112 -00 -5) - E-3467.01

Test method:

OECD Guidelines for testing of Chemicals, Paris, (1981). Guideline 201: Alga, Growth Inhibition Test.

Test Species:

Selenastrum capricornutum

Conclusion:

The concentrations of E-3467.01 which cause 50% inhibition of growth (EbC50, 0 -72h) and of growth rate (ErC50, 24 -72h) of the green alga Selenastrum capricornutum with respect to a control culture are 0.036 and 0.058 mg/L respectively (nominal concentrations based on the active component).

A concentration of 0.010 mg/L (NOEC) does not inhibit the growth of Selenastrum capricornutum.

Description of key information

Title:

Alga, Growth Inhibition Test. Effect of E-3467.01 (CAS: 112 -00 -5 ; Dodecylmethylammonium chloride) on the growth of Selenastrum capricornutum.

Timing:

The test was carried out between October 24th and October 27th 1988.

Objective:

The purpose of this test is to determine the effect of the test substance on the growth of a unicellular green algal species (Selenastrum capricornutum). The concentration of the test substance with results in a 50% reduction in either growth (EbC50) or growth rate (ErC50) relative to the control and the highest tested concentration at which ni significant inhibition of growth relative to the control occurs (No-Observed-Effect-Concentration or NOEC) are determined.

Test conditions:

Duration: 72 hours

Test containers: 200 mL borosilicate glass erlenmeyers covered with cotton wool

Volume of test solution: 100 mL of test solution in each erlenmeyer.

Light intensity: Continuous uniform illumination.

temperature: the temperature of the test solutions is maintained at 23.0 +/- 1.2°C over the 72 -hours test period

adjustment of pH: adjustment of the pH of the test solutions before inoculation is not necessary.

Shaking: In order to keep the algae in suspension and to facilitate transfer of CO2 the test erlenmeyers are shaken manually three times per day.

Initial cell concentration: the initial cell concentration of Selenastrum capricornutum in the test culture is 1.0 x 10E4 cells/mL

Test concentrations:

This test concentrations - made up in a geometric series at a concentration ratio of 2.0 - are prepared by appropriate dilution of the stock solution with algal medium: 0 (control) - 0.005 - 0.010 - 0.020 - 0.040 - 0.080 - 0.160 and 0.319 mg/L (nominal concentration based on the active component).

Replicates and controls:

The test includes 6 controls containing only algal medium and 3 replicates at each test concentrations.

Conclusion:

The concentrations of E-3467.01 which cause 50% inhibition of growth (EbC50, 0 -72h) and of growth rate (ErC50, 24 -72h) of the green alga Selenastrum capricornutum with respect to a control culture are 0.036 and 0.058 mg/L respectively (nominal concentration based on the active component).

A concentration of 0.010 mg/L (NOEC) does not inhibit the growth of Selenastrum capricornutum.

Key value for chemical safety assessment

EC50 for freshwater algae:

0.036 mg/L

EC10 or NOEC for freshwater algae:

0.01 mg/L

Additional information

ErC50 (24 - 72h) = 0.058 mg/L