2,2,6,6-tetramethyl-4-piperidylamine

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

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP study according to guideline

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2009

Report date:

2009

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method C.3 (Algal Inhibition test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

2,2,6,6-tetramethyl-4-piperidylamine

EC Number:

253-197-2

EC Name:

2,2,6,6-tetramethyl-4-piperidylamine

Cas Number:

36768-62-4

Molecular formula:

C9H20N2

IUPAC Name:

2,2,6,6-tetramethylpiperidin-4-amine

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

Samples were taken after 0h, 24h, 48h and 72h and the concentration of the test item was determined.

Test solutions

Vehicle:

no

Details on test solutions:

The test concentrations were prepared by diluting a stock solution of 1 g/L. 200 mg test substance was weighed into a beaker, mixed with culture medium and was stirred for 5 min. with a magnetic stirrer to dissolve the test substance in the test medium. Then the test substance preparation was filled into a graduated flask and made up to a total volume of 200 mL with culture medium.
The amounts corresponding to the test concentrations were pipetted into a graduated flask, made up to a total volume of 1000 mL with culture medium, and then transferred to the test vessels (for dilution scheme, see table below).

Test organisms

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Details on test organisms:

The unicellular algae Desmodesmus subspicatus was used as test organism. The organism (Strain 86.81) was obtained from “Sammlung von Algenkulturen”, Göttingen (SAG), (Collection of Algae Cultures, Institute for Plant physiology), University of Göttingen, Germany.
Three days before the start of the main experiment two flasks with 100 ml culture medium were prepared and 5 x 105 algae from stock culture were added, resulting in a final concentration of 5 x 103 cells per mL. After three days of incubation the cell concentration was determined by particle counter and was at least 16 x 5000 cells per mL. The mean of 5 measurements was calculated.
For the test an appropriate volume of the pre-culture with an amount of 7.5*10 000 cells per ml were used.

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Test conditions

Hardness:

no data

Test temperature:

25 +/- 1°C

pH:

test start: 8.1 - 9.8
test end: 8.4 -9.4

Dissolved oxygen:

no data

Salinity:

0

Nominal and measured concentrations:

nominal: 6.25, 12.5, 25.0, 50.0 and 100 mg/L
Recovery of the test substance at test end (48h) was between 99% and 114% of nominal values.

Details on test conditions:

according to guideline

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

82.6 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 2

Duration:

72 h

Dose descriptor:

EC20

Effect conc.:

122 mg/L

Nominal / measured:

estimated

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 3

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

255.8 mg/L

Nominal / measured:

estimated

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: 95% CL 229.9-292.3

Effect concentrations 4

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

25 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 5

Duration:

72 h

Dose descriptor:

LOEC

Effect conc.:

50 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Results with reference substance (positive control):

ErC50 (72h): 0.8 mg/l

Reported statistics and error estimates:

EC50 values, 95% confidence limits and NOEC were calculated with the ToxRat Professional software.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

In an algal growth inhibition test using Desmodesmus subspicatus as test species, the test substance showed no effects on growth rate after 72h exposure up to concentrations of 25 mg/l (NOEC). The EC50 is considered to be > 100 mg/L (calculated as 255.8 mg/L) under conditions tested.