Nonamethylenediamine

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:

2012-08-31 to 2012-10-24

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 (incl. QA statement)

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material:
PHYSICO-CHEMICAL PROPERTIES
- Water solubility: 80 g /100 g

Vehicle:

no

Test organisms (species):

Raphidocelis subcapitata (previous names: Pseudokirchneriella subcapitata, Selenastrum capricornutum)

Details on test organisms:

TEST ORGANISM
- Common name: Pseudokirchnerella subcapitata, old name: Selenastrum capricornutum
- Strain: subcapitata (CCAP 278/4)
- Age of inoculum (at test initiation): 3 days
- Any deformed or abnormal cells observed: Microscopic observation to verify a normal and healthy appearance of the inoculum culture and to observe any abnormal appearance of the algae (as may be caused by the exposure to the test substance) at the end of the test was performed.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Test temperature:

25 ± 2°C

pH:

Negative Control Group - pH at Day 0 : 6.27
Positive Control Group (Potassium dichromate) - pH at Day 0 : 5.58
NMDA, 50mg/l - pH at Day 0 : 7.01
NMDA, 100mg/l - pH at Day 0 : 7.76
NMDA, 125mg/l - pH at Day 0 : 8.45
NMDA, 150mg/l - pH at Day 0 : 9.45
NMDA, 175mg/l - pH at Day 0 : 9.89

Nominal and measured concentrations:

nominal concentrations: 50 mg/l, 100 mg/l, 125 mg/l, 150 mg/l and 175 mg/l

Details on test conditions:

TEST SYSTEM
- Test vessel: flask
- Initial cells density: 5,000 to 50,000 cells/ml
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 3
- No. of vessels per vehicle control (replicates): 3

TEST SYSTEM VALIDATION
Three negative control replicates were performed. The biomass in the negative control cultures should increase exponentially within the 48-hour test period with a specific growth rate of at least 0.92 day-1.
The mean coefficient of variation for section-by-section specific growth rates (days 0-1 and 1-2 for 48-hour tests) in the negative control cultures must not exceed 35 %. This criterion applies to the mean value of coefficients of variation
calculated for replicate control cultures.
The coefficient of variation of average specific growth rates during the whole test period in replicate negative control cultures must not exceed 7 % in tests with Pseudokirchneriella subcapitata (Selenastrum capricornutum).

GROWTH MEDIUM
- Standard medium used: yes
- Detailed composition if non-standard medium was used: 3N-BBM+V (Bold Basal Medium with 3-fold Nitrogen and Vitamins; modified) recommended by the Culture Collection Supplier for the Selenastrum capricornutum:
Stock solutions:
1 NaNO3 5.0g/200ml distilled water
2 CaCl2.2H2O 0.5g/200ml distilled water
3 MgSO4. 7H2O 1.5g/200ml distilled water
4 K2HPO4. 3H2O 1.5g/200ml distilled water
5 KH2PO4 3.5g/200ml distilled water
6 NaCl 0.5g/200ml distilled water
7 Trace element solution (Na2EDTA): add 0.375g Na2EDTA to 500 ml of distilled water first, and then add the minerals in exactly the following sequence: FeCl3.6H2O 48.5 mg, MnCl2.4H2O 20.5 mg, ZnCl2 2.5 mg, CoCl2.6H2O 1.0 mg, Na2MoO4.2H2O 2.0 mg.
8 Vitamin B1 stock solution: 0.012g Thiaminhydrochloride in 10 ml distilled water.
9 Vitamin B12 stock solution: 0.01g Cyanobalamin in 10 ml distilled water.

For 100 ml final medium:
1 NaNO3: 3.0 ml of stock
2 CaCl2.2H2O: 1.0 ml of stock
3 MgSO4. 7H2O: 1.0 ml of stock
4 K2HPO4. 3H2O: 1.0 ml of stock
5 KH2PO4: 1.0 ml of stock
6 NaCl: 1.0 ml of stock
7 Trace element solution: 0.6 ml of stock
8 Vitamin B1 stock solution: 0.1 ml of stock
9 Vitamin B12 stock solution: 0.1 ml of stock

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Determination of cell concentrations: by Epifluorescence Microscopy

TEST CONCENTRATIONS
- Range finding study: The concentration of 100 mg/l of the test item in algal culture media was used for the limit test.
- Test concentrations: 50 mg /l, 100 mg/l, 125 mg/l, 150 mg/l and 175 mg/l

Reference substance (positive control):

yes

Remarks:

potassium dichromate (K2Cr2O7)

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

93.5 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Details on results:

- Exponential growth in the control (for algal test): yes
- Observation of abnormalities (for algal test): no

% Inhibition of specific average growth rate related to the concentration of nonamethylenediamine.

Concentration of NMDA in algal culture media (mg/l)	Logarithm10 of concentration	% Inhibition of specific average growth rate
50	1.70	7.8
100	2.00	33.0
125	2.10	80.6
150	2.18	100

Validity criteria fulfilled:

yes

Remarks:

Negative Control: specific growth rate of at least 0.92 day-1; the mean coefficient of variation for section-by-section specific growth rates of not exceeding 35 % and the coefficient of variation of average specific growth rates of not exceeding 7 %.

Conclusions:

Based on the above study, the EC50 of the test item nonamethylenediamine (NMDA) is 93.5mg/l.

Description of key information

Based on a reliable study according to OECD 201 the EC50 of the test item NMDA is 93.5mg/l.

Key value for chemical safety assessment

EC50 for freshwater algae:

93.5 mg/L