Hexanediamide, N1,N1,N6,N6-tetrakis(2-hydroxyethyl)-

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

Study period:

2005

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline, GLP Study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1995

Report date:

1995

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

-

EC Number:

405-370-0

EC Name:

-

Cas Number:

6334-25-4

Molecular formula:

C14H28N2O6

IUPAC Name:

N,N,N',N',-tetrakis(2-hydroxyethyl)hexanediamide

Details on test material:

- Name of test material (as cited in study report): Primid
- Substance type: organic
- Physical state: liquid
- Analytical purity: 99.8%
- Purity test date: not indicated
- Lot/batch No.: not indicated
- Expiration date of the lot/batch: not indicated
- Storage condition of test material: not indicated

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

Concentrations: 0, 4.6, 10, 22, 46, 100, 220 mg/L
Sampling at 0h and 72h

Test solutions

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: A stock solution of 220 mg/L was prepared in test medium applying 5-6 minutes of magnetic stirring. Lower test concentrations were prepared by subsequent dilutions of the stock solution in test medium
The test medium source is M2 according to the ISO Standard.

Test organisms

Test organisms (species):

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

Details on test organisms:

TEST ORGANISM
- Common name: green algae
- Source: in house laboratory culture
- Age of inoculum (at test initiation): 3 days
- Method of cultivation: according to OECD guideline

ACCLIMATION
- Acclimation period: 3 days
- Culturing media and conditions (same as test or not): yes
- Any deformed or abnormal cells observed: not indicated

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Test conditions

Hardness:

24 mg/L as CaCO3

Test temperature:

22.5-23C

pH:

test medium 8.3 +/- 0.2
during the test (0h and 72h measurements):
at 0 mg/L - 8.1 and 9.3
at 4.6 mg/L - 8.0 and 9.3
at 10 mg/L - 7.7 and 9.2
at 22 mg/L - 7.2 and 9.2
at 46 mg/L - 6.8 and 9.2
at 100 mg/L - 5.0 and 5.2
at 220 mg/L - 3.1 and 3.0

Nominal and measured concentrations:

nominal - 0, 4.6, 10, 22, 46, 100, 220 mg/L
measured - 0, 4.3, 10.1, 21.9, 44.8, 101, 224/233 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: glass
- Type (delete if not applicable): open
- Material, size, headspace, fill volume: glass 100mL with 50 mL medium
- Aeration: no
- Initial cells density: 10,000 cells/mL
- Control end cells density: 1,110,000 cells/mL
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 6

GROWTH MEDIUM
- Standard medium used: yes

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: M2 according to the ISO Standard
- Culture medium different from test medium: no
- Intervals of water quality measurement: 0h and 72h except temperature which was continuous

OTHER TEST CONDITIONS
- Sterile test conditions: not indicated
- Adjustment of pH: no
- Photoperiod: continuous
- Light intensity and quality: 73-101 uE.m-2.s-1


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : inhibition of cell growth and reduction of growth rate
- Measurement method: not indicated

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 2X

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Results and discussion

Effect concentrations

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 220 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

cell number

Details on results:

- Exponential growth in the control (for algal test): yes
- Observation of abnormalities (for algal test): none indicated
- Any stimulation of growth found in any treatment: no
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: no
- Effect concentrations exceeding solubility of substance in test medium: no

Results with reference substance (positive control):

- Results with reference substance valid? yes
- EC50: appx 1 mg/L; with the EC50 a bit higher for growth rate than for biomass inhibition
- Other:

Any other information on results incl. tables

Nominal Conc - 0, 4.6, 10, 22, 46, 100, 220 mg/L

Grow Rate Inhib (% of controls) - 0, -0.3, 1.0, -0.4, -1.3, 84, 98

Biomass Inhib (% of controls) - 0, 0.5, 5.9, 1.3, -4.6, 97, 100

Growth Factor Control - 27.6

The 72h NOEC is 44.8 mg/L active ingredient (a.i.) based on measured concentration

Very possible that the effects observed at the highest test concentrations are related to the acidity of the test substance.

The measured pH values at 0 and 72 hours were:

mg/L        0h       72h

0              8.1       9.3

4.6           8.0       9.3

10            7.7       9.2

22            7.2       9.2

46            6.8       9.2

100          5.0       5.2

220          3.1       3.0

Applicant's summary and conclusion

Validity criteria fulfilled:

yes