4-methylbenzophenone

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1998-1999

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

Justification of Read-across
Currently, the availability of reliable data on 4-Methylbenzophenone is insufficient to enable the assessment of this substance with respect to its toxicological effects. However, much more information is available on benzophenone, a substance with a closely related chemical structure. 4-Methylbenzophenone and benzophenone are aromatic ketones with a comparable molecular weight (196 or 182 g/mol, respectively). Both substances share a conjugated structure, with a carbonyl group bridging two phenyl rings. The only difference is an additional methyl group in 4-Methylbenzophenone.
4-Methylbenzophenone is expected to be metabolised by the same metabolic pathways as benzophenone, with the addition of oxidation of the 4-methyl group to the corresponding alcohol and further oxidation to the carboxylic acid with its glycine and glucuronide conjugates.
From these considerations, it is very likely that 4-methylbenzophenone will also exhibit very similar effects as 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 possible toxicological properties of 4-methylbenzophenone.

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 404 (Acute Dermal Irritation / Corrosion)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.4 (Acute Toxicity: Dermal Irritation / Corrosion)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

Scantox, Lille Skensved, Denmark

Test material

Test material information

Constituent 1

Reference substance name:

Benzophenone

EC Number:

204-337-6

EC Name:

Benzophenone

Cas Number:

119-61-9

Molecular formula:

C13H10O

IUPAC Name:

benzophenone

Details on test material:

- Name of test material (as cited in study report): HR 98/660032
- Physical state: white to pale yellowish crystals
- Lot/batch No.: 50391499
- Expiration date of the lot/batch: Dec 1999
- Storage condition of test material: in refrigerator in the dark

Test animals

Species:

rabbit

Strain:

other: MOL:Russian

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: M&B, Ejby, DK-4623 Lille Skensved, Denmark
- Weight at study initiation: 2.2-2.4 kg
- Housing: individual in PPO/HIPS cages
- Diet : ad libitum
- Water : ad libitum
- Acclimation period: 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 +- 3°C
- Humidity (%): 55 +- 15%
- Air changes (per hr): 10/hour
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: From 14 Dec 1998 To: 01 January 1999

Test system

Type of coverage:

semiocclusive

Preparation of test site:

shaved

Vehicle:

other: Ethanol 96% and Diethyl phthalate (1:1)

Controls:

not required

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.5 g of the test item was moistened with 0.5 mL vehicle, or 0.5 mL of the test article solution (if diluted), were applied
- Concentration (if solution): 2, 5, 10, 25 and 100%

VEHICLE
- Amount(s) applied (volume or weight with unit): 0.5 mL

Duration of treatment / exposure:

4 hours

Observation period:

1 hour after exposure period as well as 24, 48 and 72 hours after exposure period

Number of animals:

4

Details on study design:

TEST SITE
- Area of exposure: 10x10 cm, 6 sites were selected on this area
- Type of wrap if used: gauze patches secured with 2.5 cm adhesive tapes

REMOVAL OF TEST SUBSTANCE
- Washing (if done): yes, with lukewarm water and mild soap
- Time after start of exposure: 4 hours after exposure

SCORING SYSTEM: Erythema and Eschar formation: Score 0 to 4; Oedema formation: Score 0 to 4

Results and discussion

In vivo

Results

Irritation parameter:

overall irritation score

Basis:

mean

Time point:

other: 24, 48 and 72 hours

Score:

0

Max. score:

0

Reversibility:

fully reversible

Irritant / corrosive response data:

No signs of irritations were observed at any of the concentrations tested

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

All treated skin sites were scored with 0, i.e. no irritation was induced at any of the tested concentrations. Benzophenone is therefore not subject of classification.

Executive summary:

A primary skin irritation study was performed in rabbits according to OECD 404 (1992). Benzophenone was tested at concentrations of 2, 5, 10, 25 and 100%. No signs of skin irritation were observed at any of the concentrations tested. Therefore, no classification as skin irritant is required.