4-chlorobenzophenone

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

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

Experimental test result performed using standard test guideline

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

no

Analytical monitoring:

no

Details on sampling:

- Concentrations: 0,0, 0.10, 0.17, 0.29, 0.49, 0.84 mg/l

Vehicle:

yes

Remarks:

Acetone

Details on test solutions:

The stock solution 10.0 g/l was prepared by dissolving white powder in acetone and it was 10 times diluted by acetone. Test solutions of required concentrations were prepared by mixing the stock solution of the test sample with OECD growth medium and inoculum culture.

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Details on test organisms:

TEST ORGANISM
- Common name: Green algae
- Strain: 86.81 SAG
- Source (laboratory, culture collection): Institute of Botany of the ASCR, v.v.i., Dukelska 135, Trebon, Czech Republic

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Remarks on exposure duration:

± 1 hr

Test temperature:

23 °C ± 2 °C

pH:

without adjustment,
the sample at concentration 0.84 mg/l: pH = 8.0 changed to pH = 7.9 during the test,
control: pH= 8.0 changed to pH= 7.7 during the test
control + acetone: pH = 7.9 changed to pH = 7.5 during the test

Nominal and measured concentrations:

-Nominal Concentrations: 0,0, 0.10, 0.17, 0.29, 0.49, 0.84 mg/l

Details on test conditions:

TEST SYSTEM
- Test vessel: 50 ml Glass vessel
- Type (delete if not applicable): closed, with air-permeable stopper
- Material, size, headspace, fill volume: 15 ml
- Initial cells density: 5000 cells/ml
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 3
- No. of vessels per vehicle control (replicates): 3

GROWTH MEDIUM
- Standard medium used: yes

OTHER TEST CONDITIONS
- Sterile test conditions: yes
- Adjustment of pH: No
- Photoperiod: continuous light
- Light intensity and quality: 6000 Iux - 8000 Iux


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Determination of cell concentrations: [counting chamber; electronic particle counter; fluorimeter; spectrophotometer; colorimeter]: microscope with counting chamber Cyrus I or electronic particle counter (Cellometer Auto T4 Plus, Nexcelom Bioscience LLC)

Reference substance (positive control):

yes

Remarks:

K2Cr2O7

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

0.31 mg/L

95% CI:

> 0.29 - < 0.34

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: Other details not known

Details on results:

OECD growth medium without the sample, the coefficient of variation of average growth rate in
replicates during the whole test period was 2.2 % in control and 0.9 % in control+ acetone

Results with reference substance (positive control):

ErC50 = 0.75 mg/l K2Cr2O7

Reported statistics and error estimates:

ErC50 was calculated using nonlinear regression by the software Prism 4.0 (GraphPad Software, Inc., San Diego CA)

 

Sample		Endpoint : growth rate
Sample No	Sample Information	c   (mg/l)	µ (d^-1)	I ( %)	ErC50
Control	OECD medium OECD medium + acetone	0 0	2.04 2.02	- 1.0	mg/l	95% CI mg/l
Test substance	Test substance	0.1	1.98	2	0.31	0.29 – 0.34
		0.17	1.97	2.5
		0.29	1.12	41.6
		0.49	0.30	85.1
		0.84	0.02	99

Validity criteria fulfilled:

not specified

Conclusions:

On the basis of growth rate effect of test chemical on test organism Desmodesmus subspicatus the 72 hr ErC50 value was determined to be 0.31 with 95% CI of 0.29 to 0.34 mg/l.

Executive summary:

The study of toxicity to aquatic algae was carried out according to OECD 201. The duration of study was 72 hr and was performed under static conditions. Desmodesmus subspicatus (86.81 SAG)  was taken as test organism. The source of test organism was Institute of Botany of the ASCR, v.v.i., Dukelska 135, Trebon, Czech Republic. The stock solution 10.0 g/l was prepared by dissolving white powder in acetone and it was 10 times diluted by acetone. Test solutions of required concentrations were prepared by mixing the stock solution of the test sample with OECD growth medium and inoculum culture. The nominal test concentrations taken for study were 0,0, 0.10, 0.17, 0.29, 0.49, 0.84 mg/l. The test vessel was taken as 50 ml glass vessel with air-permeable stopper. Volume of test solution was taken as 15 ml. Initial cells density was 5000 cells/ml.  Number of vessels per concentration, control, vehicle control was taken as three. Test conditions includes temperature of 23 °C ± 2 °C, pH without adjustment at highest concentration 0.84 mg/l was 8.0 changed to pH 7.9 during the test, in control pH 8.0 changed to pH 7.7 during the test, in vehicle control pH 7.9 changed to pH 7.5 during the test. A photoperiod of continuous light was provided with light intensity of 6000 lux to 8000 lux. Determination of cell concentration was done by microscope with counting chamber Cyrus I or electronic particle counter (Cellometer Auto T4 Plus, Nexcelom Bioscience LLC). Potassium dichromate was taken as reference substance. ErC50 was calculated using nonlinear regression by the software Prism 4.0 (GraphPad Software, Inc., San Diego CA). ErC50 of reference substance was determined to be 0.75 mg/l. In control  the coefficient of variation of average growth rate in replicates during the whole test period was 2.2 %  and 0.9 % in vehicle control.  On the basis of growth rate effect of test chemical on test organism Desmodesmus subspicatus the 72 hr ErC50 value was determined to be 0.31 with 95% CI of 0.29 to 0.34 mg/l. As per the value of EC50 the test chemical was considered to be classified in category 'aquatic acute/chronic 1' thus consider as toxic to aquatic algae. 

 

Description of key information

On the basis of growth rate effect of test chemical on test organism Desmodesmus subspicatus the 72 hr ErC50 value was determined to be 0.31 with 95% CI of 0.29 to 0.34 mg/l.

Key value for chemical safety assessment

EC50 for freshwater algae:

0.31 mg/L

Additional information

Different experimental studies for the toxicity to aquatic algae endpoint were reviewed for the test substance  and are summarised below:

 

The first study of toxicity to aquatic algae was carried out according to OECD 201. The duration of study was 72 hr and was performed under static conditions. Desmodesmus subspicatus (86.81 SAG)  was taken as test organism. The source of test organism was Institute of Botany of the ASCR, v.v.i., Dukelska 135, Trebon, Czech Republic. The stock solution 10.0 g/l was prepared by dissolving white powder in acetone and it was 10 times diluted by acetone. Test solutions of required concentrations were prepared by mixing the stock solution of the test sample with OECD growth medium and inoculum culture. The nominal test concentrations taken for study were 0,0, 0.10, 0.17, 0.29, 0.49, 0.84 mg/l. The test vessel was taken as 50 ml glass vessel with air-permeable stopper. Volume of test solution was taken as 15 ml. Initial cells density was 5000 cells/ml.  Number of vessels per concentration, control, vehicle control was taken as three. Test conditions includes temperature of 23 °C ± 2 °C, pH without adjustment at highest concentration 0.84 mg/l was 8.0 changed to pH 7.9 during the test, in control pH 8.0 changed to pH 7.7 during the test, in vehicle control pH 7.9 changed to pH 7.5 during the test. A photoperiod of continuous light was provided with light intensity of 6000 lux to 8000 lux. Determination of cell concentration was done by microscope with counting chamber Cyrus I or electronic particle counter (Cellometer Auto T4 Plus, Nexcelom Bioscience LLC). Potassium dichromate was taken as reference substance. ErC50 was calculated using nonlinear regression by the software Prism 4.0 (GraphPad Software, Inc., San Diego CA). ErC50 of reference substance was determined to be 0.75 mg/l. In control  the coefficient of variation of average growth rate in replicates during the whole test period was 2.2 %  and 0.9 % in vehicle control.  On the basis of growth rate effect of test chemical on test organism Desmodesmus subspicatus the 72 hr ErC50 value was determined to be 0.31 with 95% CI of 0.29 to 0.34 mg/l. As per the value of EC50 the test chemical was considered to be classified in category 'aquatic acute/chronic 1' thus consider as toxic to aquatic algae. 

 

The second study of toxicity to aquatic algae was performed according to "The Notice on the Test Method Concerning New Chemical Substances". The duration of study was 72 hr and was performed in static conditions. The test organism was taken as Pseudokirchnerella subcapitata (green algae). Statistical analysis was done by Probit method and Dunnett's test. On the basis of growth rate effect of test chemical on test organism Pseudokirchnerella subcapitata, the 72 hr NOEC and EC50 value was determined to be 0.18 and 0.67 mg/l (95% CI of 0.63 to 0.72 mg/L). Also based on biomass effect the 72 hr NOEC and EC50 value was determined to be 0.08 and 0.41 mg/l (95 % CL of 0.38 to 0.45 mg/L). As per the value of EC50 the test chemical was considered to be classified in the category 'aquatic acute/chronic 1' thus consider as toxic to aquatic algae. 

 

The third study of toxicity to aquatic algae was carried out according to German Federal Environment Agency guideline. The duration of study was 96 hr and was performed under static conditions. Scenedesmus subspicatus (green algae) was taken as test organism. The nominal concentrations taken for study were 0.05, 0.1, 0.25, 0.5 and 1 mg/l. The 20 ml of algae suspension was incubated in a shaking water bath at the test concentrations and control of plain water bath. On the basis of growth rate effect of test chemical on test organism Scenedesmus subspicatu, the 72 hr LOEC and EC50 value was determined to be 0.03 and 0.073 mg/l respectively. As per the value of EC50 the test chemical was The study of toxicity to aquatic algae was carried out according to German Federal Environment Agency guideline. The duration of study was 96 hr and was performed under static conditions. Scenedesmus subspicatus (green algae) was taken as test organism. The nominal concentrations taken for study were 0.05, 0.1, 0.25, 0.5 and 1 mg/l. The 20 ml of algae suspension was incubated in a shaking water bath at the test concentrations and control of plain water bath. On the basis of growth rate effect of test chemical on test organism Scenedesmus subspicatu, the 72 hr LOEC and EC50 value was determined to be 0.03 and 0.073 mg/l respectively. As per the value of EC50 the test chemical was considered to be classified in the category 'aquatic acute/chronic 1' thus consider as toxic to aquatic algae. 

 

On the basis of above-mentioned information, the test chemical  was considered to be classified in the category 'aquatic acute/chronic 1' thus consider as toxic to aquatic algae.