REAKTIV-ORANGE DYPR 1410

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:

01 February 1999 to 04 February 1999

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method C.3 (Algal Inhibition test)

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

Analysis of the test concentrations 9.4 mg/l, 20.7 mg/l, 45.5 mg/l, 100 mg/l plus a control; additional analysis of the test concentrations 9.4 mg/l and 100 mg/l without algal inoculum, at test start and after 72 hours of exposure.

Vehicle:

no

Details on test solutions:

Water for dilution: deionized water
Inoculum: Algal suspension taken from an exponentially growing preculture which serves to adjust an initial cell density of 10 000 cells per millilitre.
Analysis of the test concentrations 9.4 mg/l, 20.7 mg/l, 45.5 mg/l, 100 mg/l plus a control; additional analysis of the test concentrations 9.4 mg/l and 100 mg/l without algal inoculum, at test start and after 72 hours of exposure.
Solubiliser or other auxiliaries: none

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Details on test organisms:

Species: Scenedesmus subspicatus CHODAT
Origin: Institute of Plant Physiology, University of Gottingen
Cultivation (stock cultures, precultures, test cultures) : In a light chamber at 23 ±2 ⁰C and with a quantum flux which equals 120 μΣ/m2.s.
Water for dilution: deionized water

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

72 h

Post exposure observation period:

No post exposure period

Hardness:

No data

Test temperature:

No data

pH:

8.0-10.3

Dissolved oxygen:

No data

Salinity:

Not applicable.

Nominal and measured concentrations:

Test concentrations [mg/l] 1.9, 4.3, 9.4, 20.7, 45.5, 100 (nominal)

Details on test conditions:

Test procedure: Erlenmeyer flasks (300 ml) with stoppers
100 ml of test medium
light chamber and magnetic stirrer
Determination of the effects on the growth of Scenedesmus subspicatus within a 72h exposure period.
Counting: Microcellcounter Sysmex F-300 Digitana [SOP 2030-0001903-98 D)
Method of administration: stock solution (SOP 2030-6600401-96 D) (125 mg/l)
Inoculum: Algal suspension taken from an exponentially growing preculture which serves to adjust an initial cell density of 10 000 cells per millilitre.
Control: Inoculum in nutrient medium and water for dilution.
Water for dilution: deionized water

Reference substance (positive control):

no

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

> 51.6 - < 110.4 mg/L

Conc. based on:

test mat.

Basis for effect:

biomass

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 110.4 mg/L

Conc. based on:

test mat.

Basis for effect:

biomass

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

> 51.6 - < 110.4 mg/L

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 110.4 mg/L

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

51.6 mg/L

Conc. based on:

test mat.

Basis for effect:

other: Dunnett-test

Duration:

72 h

Dose descriptor:

LOEC

Effect conc.:

110.4 mg/L

Conc. based on:

test mat.

Basis for effect:

other: Dunnett-test

Details on results:

The test results refer to concentrations of the test substance, which were calculated directly from analytically determined TOC values. According to the relevant product informations, 1 mg/l TOC equals to 2.6 mg/l of the organic components of the test substance (structural formula: C18H15Na2N3O9S3; molecular weight: 559 g/mol). As these organic components correspond to 73 % of the molecular weight of the test substance 100 mg/l of the test substance equals to 28.1 mg/l of organic C.
Thus, the analytical values indicate a very good recovery rate.

Results with reference substance (positive control):

Not applicable.

Reported statistics and error estimates:

No data

STUDY EVALUATION AFTER 72 HOURS OF EXPOSURE

(SOP 2030-7000803-98 D)

 

Tab.l : Growth (b) [integral of biomass]

 

Nominal concentr. test substance [mg/1]	Growth [integral of biomass]	% inhibition [+] or % increase   [-] of growth (control  = 0 %)
control	544000	0.0
1.9	544000	0.0
4.3	535000	1.7
9.4	573000	-5.3
20.7	599000	-10.1
45.5	519000	4.6
100	298000	45.2

 

 

 

Tab. 2      Growth rate (r)

 

Nominal concentr. test substance [mg/1]	Growth rate [1/d]	% inhibition [+] or % increase [-] of growth rate (control  = 0 %)
control	1.3	0.0
1.9	1.3	0.0
4.3	1.3	0.0
9.4	1.3	0.0
20,7	1.3	0.0
45 . 5	1.3	0,0
100	1.1	15.4

Validity criteria fulfilled:

yes

Conclusions:

Toxicity to algae (mg/1):
Exposure time: 72 h
Growth (integral of biomass): EC50 > 110.4
Growth rate: EC50 > 110.4
Dunnett test:
NOEC : 51.6
LOEC :110.4

Executive summary:

Procedure: "Algal growth inhibition test" Council Directive 92/69/EEC(1992). Study conducted in compliance with GLP. 

The test results refer to concentrations of the test substance, which were calculated directly from analytically determined TOC values. According to the relevant product information, 1 mg/1 TOC equals to 2.6 mg/1 of the organic components of the test substance (structural formula: C18H15Na2N309S3; molecular weight: 559 g/mol). As these organic components correspond to 73 % of the molecular weight of the test substance 100 mg/1 of the test substance equals to 28.1 mg/1 of organic C.

Thus, the analytical values indicate a very good recovery rate.

 

Toxicity to algae (mg/1):

Exposure time: 72 h

Growth (integral of biomass): EC50 > 110.4

Growth rate: EC50 > 110.4

Dunnett test:

NOEC   : 51.6

LOEC     :110.4

 

The test results indicate no hazard potential.

 

Description of key information

Growth (integral of biomass): EC50 > 110.4
Growth rate: EC50 > 110.4
The test results indicate no hazard potential. 

Key value for chemical safety assessment

EC50 for freshwater algae:

110.4 mg/L

EC10 or NOEC for freshwater algae:

51.6 mg/L

Additional information

Procedure: "Algal growth inhibition test" Council Directive 92/69/EEC(1992). Study conducted in compliance with GLP. 

The test results refer to concentrations of the test substance, which were calculated directly from analytically determined TOC values. As these organic components correspond to 73 % of the molecular weight of the test substance 100 mg/1 of the test substance equals to 28.1 mg/L of organic C. Thus, the analytical values indicate a very good recovery rate.

 

Toxicity to algae (mg/L):

Exposure time: 72 h

Growth (integral of biomass): EC50 > 110.4

Growth rate: EC50 > 110.4

Dunnett test:

NOEC   : 51.6

LOEC     :110.4

 

The test results indicate no hazard potential.