N-methoxy-1-(2,4,6-trichlorophenyl)propan-2-amine

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:

16 January 2014 to 03 April 2014

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Freshwater Alga and Cyanobacteria, Growth Inhibition Test)

Version / remarks:

(2006, corrected 2011)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.3 (Algal Inhibition test)

Version / remarks:

2009

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: US EPA, Ecological Effects Test Guidelines, OCSPP Test Guideline 850.4500: Algal Toxicity, 2012.

Version / remarks:

2012

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

For measurement of the actual concentrations of the test item, duplicate samples were taken from the test media of all test concentrations at the start of the test (without algae) and at the end of the test (containing algae). At the same sampling times, duplicate samples were also taken from the control.

For sampling at the end of the test, the test medium of the treatment replicates was pooled.

Vehicle:

no

Details on test solutions:

Due to the low water solubility of the test item, 100 mg of CA5204A was dispersed in 1000 mL of test water, supported by ultrasonic treatment for 15 minutes and intense stirring for 3 hours in the dark. This dispersion was allowed to settle for 30 minutes and the middle phase of the dispersion was then carefully separated from the non-dissolved test item and used as test medium. This stock solution was used for the highest test concentration, and in a series of dilutions with test water for the lower test concentrations. The control consisted of culture medium only. The test media were prepared just before the start of the test.

Details on test organisms:

Species: Pseudokirchneriella subcapitata, Strain No. 61.81 SAG
Source: Laboratory cultures, originally obtained from Collection of Algal Cultures (SAG, Institute for Plant Physiology, University of Göttingen, 37073 Göttingen, Germany).

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Hardness:

15 mg/L as CaCO3

Test temperature:

22°C

pH:

test start: 7.1 toi 7.3
test end: 8.5 to 9.1

Nominal and measured concentrations:

At the start of the test, the analytically determined concentrations of the substance in the test media (dilutions 1:1000, 1:320, 1:100, 1:32, 1:10, 1:3.2
and the stock solution) were 0.0474, 0.143, 0.451, 1.41, 4.50, 14.1 and 45.9 mg/L, respectively. During the test period of 96 hours, a decrease of test item concentration in the test media occurred. At the end of the test, 41 to 77% of the initially measured concentrations were found.

Details on test conditions:

Test vessels: 50 mL Erlenmeyer flasks containing 15 mL of media covered with glass dishes
Test medium: Reconstituted water (AAP algal medium) prepared according to OECD guideline 201
Replication: Six vessels for the control and three vessels for each test concentration
Starting cell density: 0.5 × 104 cells/mL

Reference substance (positive control):

yes

Remarks:

Potassium dichromate is tested twice a year (last study – D82052, September 2013)

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

4.2 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

1.9 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

other: Yield

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

2.2 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

biomass

Duration:

96 h

Dose descriptor:

EC50

Effect conc.:

4.1 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

96 h

Dose descriptor:

EC50

Effect conc.:

1.9 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

other: Yield

Duration:

96 h

Dose descriptor:

EC50

Effect conc.:

2 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

biomass

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

0.03 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

Details on results:

after 72 h after 96 h
(mg CA5204A/L) (mg CA5204A/L)
Parameter AUC Growth rate Yield AUC Growth rate Yield
EC50 2.2 4.2 1.9 2.0 4.1 1.9
95% CI 1.8-2.7 4.0-5.6 1.5-2.4 1.7-2.3 3.9-4.8 1.6-2.2
EC20 1.1 2.9 1.0 1.2 2.8 1.2
95% CI 0.73-1.4 1.5-3.3 0.68-1.3 0.91-1.4 1.6-3.2 1.0-1.4
EC10 0.75 2.4 0.75 0.89 2.3 0.98
95% CI 0.43-1.0 0.76-2.9 0.43-1.0 0.64-1.1 0.91-2.8 0.79-1.2
NOEC n.d. 0.030 n.d. n.d. 0.030 0.030
LOEC 0.030 0.10 0.030 0.030 0.10 0.10

Validity criteria fulfilled:

yes

Conclusions:

Based on nominal concentrations, the 72-hour ErC50 was 4.2 mg CA5204A/L, the EyC50 was 1.9 mg CA5204A/L and the EbC50 was 2.2 mg CA5204A/L. The 96-hour ErC50 was 4.1 mg CA5204A/L, the EyC50 was 1.9 mg CA5204A/L and the EbC50 was 2.0 mg CA5204A/L.
The LOEC at 72 hours, based on growth rate was 0.1 mg CA5204A/L and based on biomass integral and yield was 0.030 mg CA5204A/L. The corresponding NOEC, based on growth rate was 0.030 mg CA5204A/L. The 72-hour NOEC based on biomass integral and yield could not be determined. The LOEC at 96 hours, based on growth rate and yield was 0.1 mg CA5204A/L, and based on biomass integral was 0.030 mg CA5204A/L. The corresponding NOEC based on growth rate and yield was 0.030 mg CA5204A/L. The 96-hour NOEC based on biomass integral could not be determined.

Executive summary:

The toxicity of CA5204A to the green algaPseudokirchneriella subcapitatawas determined. Algae were exposed to a stock solution with the loading rate of 100 mg CA5204A/L and dilutions 1:1000, 1:320, 1:100, 1:32, 1:10 and 1:3.2 of the stock solution (mean measured concentrations of 40 (stock solution), 0.030, 0.097, 0.33, 1.1, 3.8 and 12 mg CA5204A/L), alongside a culture medium control.Based on measured concentrations, the 72-hour E_rC₅₀was 4.2 mg CA5204A/L, the E_yC₅₀was 1.9 mg CA5204A/L and the E_bC₅₀was 2.2 mg CA5204A/L. The 96-hour E_rC₅₀was 4.1 mg CA5204A/L, the E_yC₅₀was 1.9 mg CA5204A /L and the E_bC₅₀was 2.0 mg CA5204A/L.

Due to the low water solubility of the test item, a dispersion of the test item with the loading rate of 100 mg/L was continuously stirred at room temperature in the dark over 3 hours. Then, the dispersion was let to settle for 30 minutes and thereafter the middle phase of the dispersion was carefully separated from the non-dissolved test item and used as test medium. The stock solution with the loading rate of 100 mg/L and dilutions 1:3.2, 1:10, 1:32, 1:100, 1:320 and 1:1000 of the stock solution with the loading rate of 100 mg/L were used as test media. Additionally, a control was tested in parallel.

The preparation of the test media was based on the OECD Guidance Document on Aquatic Toxicity Testing of Difficult Substances and Mixtures, 2000.

At the start of the test, the analytically determined concentrations of CA5204A in the test media (dilutions 1:1000, 1:320, 1:100, 1:32, 1:10, 1:3.2 and the stock solution) were 0.0474, 0.143, 0.451, 1.41, 4.50, 14.1 and 45.9 mg/L, respectively. During the test period of 96 hours, a decrease of test item concentration in the test media occurred. At the end of the test, 41 to 77% of the initially measured concentrations were found.

Description of key information

Based on measured concentrations, the 72-hour E_rC₅₀was 4.2 mg CA5204A/L, the E_yC₅₀was 1.9 mg CA5204A/L and the E_bC₅₀was 2.2 mg CA5204A/L. The 96-hour E_rC₅₀was 4.1 mg CA5204A/L, the E_yC₅₀was 1.9 mg CA5204A /L and the E_bC₅₀was 2.0 mg CA5204A/L.

Key value for chemical safety assessment

EC50 for freshwater algae:

4.2 mg/L

EC10 or NOEC for freshwater algae:

0.03 mg/L