3-aminomethyl-3,5,5-trimethylcyclohexylamine

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:

1992-08-04 to 1992-08-07

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Guideline study with acceptable restrictions: no analytical monitoring

Qualifier:

according to guideline

Guideline:

EU Method C.3 (Algal Inhibition test)

Version / remarks:

Cited as Directive 87/302/EEC, part C, p. 89 (Algal inhibition test)

GLP compliance:

yes

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

Stock solution: 1 g test substance/l (deionised water), no vehicle or solvent

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Details on test organisms:

- Strain: CHODAT (86.81 SAG)
- Source/supplier: Origin: Institut fuer Wasser-, Boden- und Lufthygiene, Berlin, further bred inhouse
- Laboratory culture: From a stock culture, a preculture is seeded three days before begin of test. Test cultures are seeded from the latter.
- Method of cultivation: Erlenmeyer flasks on tables exposed to light
- Controls: yes
- Initial cell concentration: ca. 20,000 cells/ml

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Test temperature:

24 +/- 2 degree C

pH:

7.9-8.9 at start,
8.4-9.0 at end of test

Nominal and measured concentrations:

Nominal: control; 0.75; 1.5; 3.0; 6.0; 12.5; 25; 50 mg/l

Details on test conditions:

- Number of replicates: 5 (exposed) or 8 (control)
- Method of cultivation: Erlenmeyer flasks on tables exposed to light
- Intensity of irradiation: ca. 8000 lux white
- Monitoring of algae: photometric at 685 nm, calibration with standard curve
- Renewal of test solution: no

Reference substance (positive control):

not specified

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

37 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

cell number

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

3.1 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

cell number

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 50 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Key result

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

11.2 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.:

1.5 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

cell number

Details on results:

Probit analysis according to Cavalli-Sforza (1972) was applied to the areas under the growth curves.

RESULTS
- Cell density data: (x 1.0E+04 cells/ml)

concentration	0 hours	24 hours	48 hours	72 hours
control	2	6	25	98
0.75 mg/l	2	5	24	97
1.5 mg/l	2	6	24	92
3.0 mg/l	2	6	23	82
6.0 mg/l	2	6	24	78
12.5 mg/l	2	7	25	69
25 mg/l	2	5	20	54
50 mg/l	2	4	10	31

Validity criteria fulfilled:

not specified

Conclusions:

The EC50 values (72 hours) were determined as >50 mg/L (growth rate) and 37 mg/L (cell number) indicating that the test substance may be harmful to algae.

Executive summary:

In a 72 hour toxicity study, cultures of Scenedesmus subspicatus were exposed to 3-aminomethyl-3,5,5-trimethylcyclohexylamine

at nominal concentrations of 0.75; 1.5; 3.0; 6.0; 12.5; 25; 50 mg/l under static conditions in accordance with EU Method C3. The NOEC and EC50values based on biomass were 1.5 mg/L and 37 mg/L, respectively. The 72 h-EC50 value based on growth rate was >50 mg/L. There were no compound related phytotoxic effects.

Growth rate:
72 hr ErC50:  >50 mg/L    95% CL: n.a.

72 hr ErC10:  11.2 mg/L    95% CL: n.a.
72 hr NOEC: not available

Biomass:
72 hr EbC50:  37 mg/L 95% CL: n.a.

72 hr NOEC: 1.5 mg/L

 

The study was assessed as "reliable without restriction".

Description of key information

Cited from SIAR for SIAM 18 (Paris, France, April 20–23, 2004):
"The growth inhibition of 3-aminomethyl-3,5,5-trimethylcyclohexylamine on the freshwater alga Scenedesmus subspicatus was tested by Hüls AG (1993b) according to a test procedure similar to OECD Guideline 201. The algae were exposed to 7 concentrations between 0.75 and 50 mg/l and
one control. Based on growth rate an ErC50 of > 50 mg/l and a 72h-ErC10 of 11 mg/l (NOEC 1.5 mg/l) were determined (nominal concentrations). Based on biomass development an EbC50 of 37 mg/l and a 72h-EbC10 of 3 mg/l were determined."

Key value for chemical safety assessment

EC50 for freshwater algae:

50 mg/L

EC10 or NOEC for freshwater algae:

11.2 mg/L

Additional information

Desmodesmus subspicatus 72h-ECr50 > 50 mg/L

Desmodesmus subspicatus 72h-ECr10 = 11.2 mg/L