4-methylbenzophenone

Short-term toxicity to aquatic invertebrates

Administrative data

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

14.09.2011 to 16.09.2011

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Well documented GLP study according to OECD guideline 202; study conducted with benzophenone, a substance with a closely related structure and very similar physico-chemical properties

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2011

Report date:

2011

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Methanone, diphenyl-

IUPAC Name:

Methanone, diphenyl-

Constituent 2

Reference substance name:

Benzophenone

EC Number:

204-337-6

EC Name:

Benzophenone

Cas Number:

119-61-9

Molecular formula:

C13H10O

IUPAC Name:

benzophenone

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

The concentration of the test item in the aqueous phase of the test was assessed by chemical analysis. Test samples were analysed from fresh media at test start and at 24h. Samples of aged test media were analysed after 24h and at the end of the test. All test concentrations and the control were analysed.

Test solutions

Vehicle:

no

Details on test solutions:

The test item was distributed to the replicate beakers using an aqueous stock solution. The stock solution (50.1 mg test item/L) was prepared in dilution water and stirred for 24 h. The individual test solutions were prepared by dilution of the stock solution with dilution water and distributed to the test beakers.

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

4-24 hours old (juvenile) , breeding at test facility.

Study design

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Post exposure observation period:

None

Test conditions

Hardness:

The total hardness of the dilution water (1.3 mmol/L equivalent to 107mg CaCO3) was below the recommended level of 140mg/L. However, the suitability of the soft dilution water has been demonstrated in former acute immobilisation tests on the same species.

Test temperature:

The water temperature ranged between 20.3°C and 20.7°C.

pH:

The pH values throughout the test were within a range of pH 7.6 – 8.6 at all treatment levels.

Dissolved oxygen:

The oxygen saturation was between 7.8 mg/L and 8.7 mg/L.

Salinity:

Conductivity was 314.0 µS/cm

Nominal and measured concentrations:

Nominal concentrations: 2.1, 4.7, 10.3, 22.7, and 50.1mg/L.
Maesured concentrations: 2.1, 4.47, 8.78,17.9, and 37.4mg/L. Due to recovery rates outside the range of 80 – 120 % of nominal for the highest treatmentmean measured concentrations were applied for effect assessment.

Details on test conditions:

Four replicates per treatment with 5 specimens per replicate were conducted.

Reference substance (positive control):

yes

Remarks:

K2Cr2O7

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

6.784 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 5.514-8.327

Effect concentrations 2

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

4.47 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Any other information on results incl. tables

Immobilizationafter 24 h and 48 h. Mean values [%].

Concentrations given as mean measured.*significantdifference when compared with control.

Incubation	Control	2.1mg/L	4.47mg/L	8.78mg/L	17.9mg/L	37.4mg/L
24 h	0	0	5	45	100	100
48 h	0	5	10	70	100	100

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The means of initial and aged measured concentrations were 2.1, 4.47, 8.78,17.9, and 37.4mg/L, corresponding with 100, 95, 85, 79, and 75 % of the nominal loading.
The study resulted in a NOEC of 4.47mg/L and in an EC50 of 6.784 mg/L (95% CL = 5.514 – 8.327). Based on the similar structure and physico-chemical properties a very similar fate and behavior of 4 -methylbenzophenone can be assumed. Therefore it can be concluded that the acute toxicity of 4 -methylbenzophenone will be very similar to that of benzophenone. Therefore, and furthermore with respect to animal welfare, the performance of any new experimental tests on 4-methylbenzophenone is assumed to be not justifiable. Instead, results from reliable key studies performed with benzophenone can be regarded as a sound basis for assessing the environmental effects of 4-methylbenzophenone..

Executive summary:

The GLP study was performed acc. to OECD 202. Nominal test item concentrations of benzophenone were 2.1, 4.7, 10.3, 22.7, and 50.1 mg/L. The chemical analysis showed that the mean measured test item concentrations were between 68 % and 93 %, and 103 % and 111 % of nominal loadings,respectively. The means of initial and aged measured concentrations were 2.1, 4.47, 8.78,17.9, and 37.4mg/L, corresponding with 100, 95, 85, 79, and 75 % of the nominal loading.

The study resulted in a NOEC of 4.47 mg/L and in an EC50 of 6.784 mg/L (95% CL = 5.514 – 8.327).

Based on the similar structure and physico-chemical properties a very similar fate and behavior of 4 -methylbenzophenone can be assumed. Therefore it can be concluded that the acute toxicity of 4 -methylbenzophenone will be very similar to that of benzophenone. Therefore, and furthermore with respect to animal welfare, the performance of any new experimental tests on 4-methylbenzophenone is assumed to be not justifiable. Instead, results from reliable key studies performed with benzophenone can be regarded as a sound basis for assessing the environmental effects of 4-methylbenzophenone.