3-amino-2,4,6-triiodobenzoic acid

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:

13 July 1999 to 16 July 1999

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1999

Report date:

1999

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method C.3 (Algal Inhibition test)

Deviations:

no

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

3-amino-2,4,6-triiodobenzoic acid

EC Number:

221-493-0

EC Name:

3-amino-2,4,6-triiodobenzoic acid

Cas Number:

3119-15-1

Molecular formula:

C7H4I3NO2

IUPAC Name:

3-amino-2,4,6-triiodobenzoic acid

Test material form:

solid: bulk

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: Schering, batch# 37055008

Sampling and analysis

Analytical monitoring:

not specified

Details on sampling:

The chlorophyll fluorescene in the test and control solutions were determined after 24, 48 and 72 hours of incubation. All measurements were made by means of fluorescence photometer at a wavelength of 320 adn 800 nm for agitation adn measurement, respectively. Sampling volume and sampling time was electronically controlled.

Test solutions

Vehicle:

yes

Remarks:

demineralized water

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): demineralized water
- Concentration of vehicle in test medium (stock solution and final test solution(s) or suspension(s) including control(s)): Test solution introduced into demineralized water at a concentration of 125 mg/L kept for approx. 30 min in an ultrasonic bath and stirred for 24 hours.
- Evidence of undissolved material (e.g. precipitate, surface film, etc.):

Test organisms

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Details on test organisms:

TEST ORGANISM
- Common name: green algae
- Source (laboratory, culture collection): The algae was obtained from the "Sammlung von Aldenkuturen, Universitat Gottingen"
- Age of inoculum (at test initiation): no reported

ACCLIMATION
- Acclimation period:
- Culturing media and conditions (same as test or not): The algae was stored on slant agar containing a nutrient solution under standard conditions (10-15 C, diffuse light of 12h/12h). The culture was dissolved in a liquid nutrient solution and subsequently transferred approximately once weekly.

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Test conditions

Test temperature:

23 - 24 degrees celcius

pH:

8 - 10.8

Nominal and measured concentrations:

The highest concentration with a nominal concentration of 100 mg/L, then the solution was diluted by: 1:1.25; 1:2.5; 1:5; 1:25; 1:50; and 1:100; the resulting concentrations (nominally) were 100 mg/L, 50 mg/L, 25 mg/L, 5 mg/L, 2.5 mg/L, 1.25 mg/L, respectively.

Details on test conditions:

TEST SYSTEM
- Test vessel: not described
- Type (delete if not applicable): open
- No. of organisms per vessel: 10,000 cells/mL
- No. of vessels per concentration (replicates): triplicate
- No. of vessels per control (replicates): 6 vessels

GROWTH MEDIUM
- Standard medium used: yes, then diluted to several concentration ratios.

Reference substance (positive control):

no

Results and discussion

Effect concentrations

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: no inhibition effects on growth up to 100 mg/L

Details on results:

- Exponential growth in the control (for algal test): At 0 hours the mean fluorescence was 0.25 mV in the controls. The growth increased 32-fold over 72 hours in the controls. The coefficient of variation was in one case (2.5 mg/L) at 72 hours was higher than 23% (77%) due to natural variability.
- Observation of abnormalities (for algal test): no damaged cells were observed.

Reported statistics and error estimates:

The values for the average area below the growth curves, specific growth rate, and the percentage inhibition were calculated by the computer program Abimed "AlgenTest XT 2.21". The The EbC50 (72h - biomass) and the ErC50 (72h - growth rate) were not calculated due to the lack of inhibitory effects.

Any other information on results incl. tables

Dilution of ZK 2218	Concentration (nominal) of ZK 2188 (mg/L)	Inhibition in percent
		Biomass (integral)	Growth rate
Control	0	0	0
1:100	1.25	-13.2	-4.3
1:50	2.5	27.6	22.2
1:25	5.00	-11.7	-4.8
1:5	25.00	-29.5	-3.5
1:2.5	50.00	-31.1	-7.1
1:1.125	100.00	-21.1	-7.8

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Remarks:

The validity criteria recommended by the guideline (i.e. >= 16 fold increase of algae cells after 72 hours in the controls) were fulfilled.

Conclusions:

The test substance had no inhibitory effect on the growth of Scenedesmus subspicatus up to 100 mg/L, therefore it was concluded the test substance was not toxic to the green algae.

Executive summary:

The green algae, Scenedesmus subspicatus, was used to tested the growth inhibition effect of the test substance, ZK 2218, at test concentrations: 0, 1.25, 2.5, 5, 25, 50, and 100 mg/L. The validity criteria recommended by the guideline  (i.e. >= 16 fold increase of algae cells after 72 hours in the controls) were fulfilled. The test substance had no inhibitory effect on the growth of Scenedesmus subspicatus up to 100 mg/L, therefore it was concluded the test substance was not toxic to the green algae.