4-chlorobenzophenone

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

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 202 (Daphnia sp. Acute Immobilisation Test)

GLP compliance:

no

Analytical monitoring:

no

Details on sampling:

- Concentrations: 0,0, 0.5,1.0,2.0,4.0,8.0 mg/l nominal concentration were used

Vehicle:

yes

Remarks:

acetone

Details on test solutions:

The stock solution 10.0 g/l was prepared by dissolving white powder in acetone. Test solutions of required concentrations were prepared by mixing the stock solution of the test sample in reconstituted water.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Water flea
- Strain: Straus
- Source: Own breeding at University of Chemistry and Technology, Prague
- Age at study initiation (mean and range, SD): The animals used for the test shall be less than 24 h old and should not be first brood progeny
- Feeding during test: No feeding

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Remarks on exposure duration:

± 1 hr

Test temperature:

20±1°C

pH:

sample at concentration 8.0 mg/l: pH = 7.8 changed to pH = 7.9 during the test,
control: pH = 7.8 did not change during the test
control + acetone: pH = 7.9 changed to pH = 7.8 during the test

Dissolved oxygen:

higher than 7.5 mg/L at the end of test

Nominal and measured concentrations:

0,0, 0.5,1.0,2.0,4.0,8.0 mg/l nominal concentration were used

Details on test conditions:

TEST SYSTEM
- Test vessel: 50 ml glass vessel
- fill volume: 25 ml
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water:
Natural water (surface or ground water), reconstituted water or dechlorinated tap water are acceptable as culturing and dilution water if D. magna survives in it for the duration of the culturing, acclimation and testing without showing signs of stress. Waters in the range pH 6 to pH 9, with hardness between 140 mg/l and 275 mg/l (as CaCO3) are recommended.
As an example, the preparation of dilution water meeting the requirements is described below.
Dissolve known quantities of reagents in water. The dilution water prepared shall have a pH of 7.8 ± 0.5, a hardness of (225 ± 50) mg/l (expressed as CaCO3), a molar Ca + Mg ratio close to 4 + 1 and a dissolved oxygen concentration above 7 mg/l.

Prepare the solutions specified below:
- Calcium chloride solution: Dissolve 117.6 g of calcium chloride dihydrate (CaCl2.2H2O) in water (4.2) and make up to 1 l with water (4.2).
- Magnesium sulfate solution: Dissolve 49.3 g of magnesium sulfate heptahydrate (MgSO4.7H2O) in water (4.2) and make up to 1 l with water (4.2).
- Sodium bicarbonate solution: Dissolve 25.9 g of sodium bicarbonate (NaHCO3) in water (4.2) and make up to 1 l with water (4.2).
- Potassium chloride solution: Dissolve 2.3 g of potassium chloride (KCI) in water (4.2) and make up to 1 l with water (4.2).

Mixing
Mix 2.5 ml of each of the four solutions and make up to 1 l with water.
The dilution water shall be aerated until the dissolved oxygen concentration has reached saturation and the pH has stabilized. If necessary, adjust the pH to 7.8 ± 0.5 by adding sodium hydroxide (NaOH) solution or hydrochloric acid (HCI). The dilution water prepared in this way shall not be further aerated before use.

- Sodium hydroxide solution, e.g. [NaOH] : 1 mol/l.
- Hydrochloric acid, e.g. [HCl] : 1 mol/l.

Reference substance:
Dissolve 600 mg of potassium dichromate (K2Cr2O7) in water and make up to 1 l with water (4.2).

OTHER TEST CONDITIONS
- Adjustment of pH: no adjustment done
- Photoperiod: No - Darkness
- Light intensity:

CALCULATION:
EC50 was calculated using non linear regression by the software Prism 4.0

Reference substance (positive control):

yes

Remarks:

Potassium dichromate (K2Cr2O7)

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

2.1 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 95 % CI:1.9-2.5 mg/l

Results with reference substance (positive control):

- Results with reference substance valid
- EC50: 0.73 mg/L (24 hours)

Reported statistics and error estimates:

EC50 was calculated using non linear regression by the software Prism 4.0

Validity criteria fulfilled:

yes

Conclusions:

The median effective concentration (EC50) for the test substance, in Daphnia magna was determined to be 2.1 mg/L on the basis of mobility inhibition effects in a 48 hour study.

Executive summary:

The study of short term toxicity to aquatic invertebrates was carried out according to OECD 202.  The duration of study was 48 hr and was performed under static conditions.  Daphnia magna (stratus) was taken as test organism. Source of test organisms was University of Chemistry and Technology, Prague. Age of test organism at study initiation was < 24 hr old. The stock solution 10.0 g/l was prepared by dissolving white powder in acetone. Test solutions of required concentrations were prepared by mixing the stock solution of the test sample in reconstituted water. Test concentration taken in study were control, vehicle control and  0.5, 1.0 ,2.0, 4.0 ,8.0 mg/l nominal concentration were used. Test vessel was taken as 50 ml glass vessel with fill volume of 25 ml.  Number of organisms per vessel was taken as five. Number of vessels per concentration (replicates) was taken as four. Potassium dichromate was taken as reference substance. Test conditions includes temperature of 20 ± 1 °C. At highest concentration pH  7.8 changed to pH  7.9 during the test. In control pH was of  7.8 and in vehicle control  pH 7.9 changed to pH 7.8 during the test. Dissolved oxygen was found to be > 7.5 mg/L at the end of test. The test was performed in the dark conditions. The statistical analysis was done by using  non linear regression by the software Prism 4.0. The EC50 value of reference substance was determined to be 0.73 mg/l in duration of 24 hr. On the basis of mobility effect of test chemical on test organism daphnia magna the 48 hr EC50 value was determined to be 2.1 mg/l. As per the value of EC50 the test chemical was considered to be classified in category 'aquatic chronic 2' thus consider as toxic to aquatic invertebrates. 

Description of key information

The median effective concentration (EC50) for the test substance, in Daphnia magna was determined to be 2.1 mg/L on the basis of mobility inhibition effects in a 48 hour study.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

EC50

Effect concentration:

2.1 mg/L

Additional information

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

 

The first study of short term toxicity to aquatic invertebrates was carried out according to OECD 202.  The duration of study was 48 hr and was performed under static conditions.  Daphnia magna (stratus) was taken as test organism. Source of test organisms was University of Chemistry and Technology, Prague. Age of test organism at study initiation was < 24 hr old. The stock solution 10.0 g/l was prepared by dissolving white powder in acetone. Test solutions of required concentrations were prepared by mixing the stock solution of the test sample in reconstituted water. Test concentration taken in study were control, vehicle control and  0.5, 1.0 ,2.0, 4.0 ,8.0 mg/l nominal concentration were used. Test vessel was taken as 50 ml glass vessel with fill volume of 25 ml.  Number of organisms per vessel was taken as five. Number of vessels per concentration (replicates) was taken as four. Potassium dichromate was taken as reference substance. Test conditions includes temperature of 20 ± 1 °C. At highest concentration pH  7.8 changed to pH  7.9 during the test. In control pH was of  7.8 and in vehicle control  pH 7.9 changed to pH 7.8 during the test. Dissolved oxygen was found to be > 7.5 mg/L at the end of test. The test was performed in the dark conditions. The statistical analysis was done by using  non linear regression by the software Prism 4.0. The EC50 value of reference substance was determined to be 0.73 mg/l in duration of 24 hr. On the basis of mobility effect of test chemical on test organism daphnia magna the 48 hr EC50 value was determined to be 2.1 mg/l. As per the value of EC50 the test chemical was considered to be classified in category 'aquatic chronic 2' thus consider as toxic to aquatic invertebrates. 

 

The second study of short-term toxicity to aquatic invertebrates was carried out according to guideline "The Notice on the Test Method Concerning New Chemical Substances". The duration of study was 48 hr performed under static conditions. Statistical analysis was done by Probit method. On the basis of mobility effect of test chemical on test organism Daphnia magna the 24 hr NOEC, EC50 and EC100 value was determined to be 1.75 mg/l, 2.34 mg/l (95 % CI of 2.11 - 2.59 mg/L) and >3.86 mg/L respectively. Based on mobility effect of test chemical on test organism Daphnia magna the 48 hr NOEC, EC50 and EC100 value was determined to be 1.15 mg/l, 1.87 mg/l (95 % CI of 1.71 - 2.07 mg/L) and 2.59 mg/L respectively. As per the value of EC50 the test chemical was considered to be classified in category 'aquatic chronic 2' thus consider as toxic to aquatic invertebrates. 

 

The third study of short-term toxicity to aquatic invertebrates was carried out. The duration of study was 48 hr and was performed under static conditions. Daphnia pulex (water flea) was taken as test organism. On the basis of mobility effect of test chemical on test organism Daphnia pulex the 48 hr EC50 value was determined to be 3.2 mg/l. As per the value of EC50 the test chemical was considered to be classified in category 'aquatic chronic 2' thus consider as toxic to aquatic invertebrates. 

 

On the basis of above-mentioned information, the test chemical was considered to be classified in the category 'aquatic chronic 2' thus consider as toxic to aquatic invertebrates.