Acetophenone

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

November 1980

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

test procedure in accordance with national standard methods with acceptable restrictions

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1980

Report date:

1980

Materials and methods

Test guideline

Test guideline 1

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Deviations:

yes

Remarks:

(more severe exposure conditions: prolonged skin contact of 24 hrs, occlusive dressing, treatment of intact and scarified skin, scoring of skin lesions at 24 and 72 hrs)

Test guideline 2

Qualifier:

according to guideline

Guideline:

other: Consumer Product Safety Commission of the USA, Code of Federal Regulations, Title 16, Section 1500.41

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

Acetophenone

EC Number:

202-708-7

EC Name:

Acetophenone

Cas Number:

98-86-2

Molecular formula:

C8H8O

IUPAC Name:

1-phenylethanone

Details on test material:

- Physical state: clear fluid
- Storage condition of test material: without special instructions

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: J. Scheele, Büderich/Westfalen, 4760 Werl, Germany
- Age at study initiation: no data
- Weight at study initiation: no data
- Housing: single
- Diet: ad libitum
- Water: ad libitum
- Acclimation period: no data

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 +- 1 °C
- Photoperiod (hrs dark / hrs light): 12/12

Test system

Type of coverage:

occlusive

Preparation of test site:

shaved

Remarks:

shaved, or shaved and scarified

Vehicle:

unchanged (no vehicle)

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied: 0.5 mL

Duration of treatment / exposure:

24 hrs

Observation period:

24 and 72 hrs after start of exposure

Number of animals:

6

Details on study design:

TEST SITE
- Application: the test substance was dispensed on 2.5 x 2.5 cm2 patches which were then applied to the prepared skin areas and fixed by elastoplast; patches were removed after 24 hrs of skin contact
- Area of exposure: 2.5 x 2.5 cm2
- Type of wrap if used: unpermeable material as e.g. a rubber cloth

SCORING SYSTEM: according to Draize, comparable to OECD Guideline 404 (for details see Table 1)
Calculation of primary dermal irritation index:
sum of the scores of each animal for [(Erythema and eschar formation) + (Oedema formation) from intact skin] + [(Erythema and eschar formation) + (Oedema formation) from scarified skin] divided by 24; maximal achievable value is 8.0
For criteria for classification see Table 2

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

primary dermal irritation index (PDII)

Basis:

mean

Time point:

other: 24 hrs

Score:

0.63

Reversibility:

fully reversible within: 48 hrs after termination of application

Remarks on result:

other: includes reactions both for intact and abraded skin

Results 2

Irritation parameter:

primary dermal irritation index (PDII)

Basis:

mean

Time point:

other: 24 and 72 hrs

Score:

0.5

Reversibility:

fully reversible within: 48 hrs after termination of application

Remarks on result:

other: reaction for intact sklin

Results 3

Irritation parameter:

erythema score

Remarks:

intact skin

Basis:

mean

Remarks:

6 animals

Time point:

24 h

Score:

0.33

Max. score:

4

Reversibility:

fully reversible within: 72 hrs

Results 4

Irritation parameter:

erythema score

Remarks:

intact skin

Basis:

mean

Remarks:

6 animals

Time point:

72 h

Score:

0

Max. score:

4

Reversibility:

fully reversible within: 72 hrs

Results 5

Irritation parameter:

erythema score

Remarks:

intact skin

Basis:

mean

Remarks:

6 animals

Time point:

24/48/72 h

Score:

ca. 0.17

Max. score:

4

Reversibility:

fully reversible within: 72 hrs

Results 6

Irritation parameter:

edema score

Remarks:

intact skin

Basis:

mean

Remarks:

6 animals

Time point:

24 h

Score:

0.67

Max. score:

4

Reversibility:

fully reversible within: 72 hrs

Results 7

Irritation parameter:

edema score

Remarks:

intact skin

Basis:

mean

Remarks:

6 animals

Time point:

72 h

Score:

0

Max. score:

4

Reversibility:

fully reversible within: 72 hrs

Results 8

Irritation parameter:

edema score

Remarks:

intact skin

Basis:

mean

Remarks:

6 animals

Time point:

24/48/72 h

Score:

ca. 0.33

Max. score:

4

Reversibility:

fully reversible within: 72 hrs

Irritant / corrosive response data:

see Table 3

Any other information on results incl. tables

Table 3: Overview on skin reactions after single occlusive application of acetophenone for 24 hrs (scores at the end of the exposure period)

Rabbit No.	Erythema score		Edema score
	intact skin	scarified skin	intact skin	scarified skin
1	1	1	1	1
2	1	1	1	1
3	0	0	1	1
4	0	0	1	1
5	0	2	0	1
6	0	0	0	0

All changes were fully reversible within the following 48 hrs: all scores were 0

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

With a primary irritation index of 0.5 after a 24-hr contact with intact skin, the classification would be "not irritating" according to the ETAD criteria.
No classification according to EU criteria is expected as mean irritation scores for erythema or edema were significantly below the critical value of 2.0 even under the conditions of this test with a prolonged contact time of 24 hrs instead of 4 hrs.

Executive summary:

Skin irritation scores according to Draize were assessed on skin sites of six rabbits (both shaved intact skin or shaved scarified skin) following a 24-hr occlusive application of 0.5 mL acetophenone on a patch. Except for the prolonged skin contact the testing procedure was comparable to OECD Guideline 404. Findings at the end of exposure on intact skin were very slight erythema in 2/6 rabbits and very slight oedema in 4/6 rabbits. Abraded skin sites showed very slight erythema in 2/6 and slight erythema in 1/6, and very slight oedema in 5/6 rabbits. All effects were fully reversible within the following 48 hrs. With a primary irritation index (PII) of 0.63 after a 24-hr skin contact, acetophenone was assessed as slightly irritating to rabbit skin according to ETAD criteria (PII of 0.6 -3.0) when the reactions of both intact and scarified skin were considered. With a PII of 0.5 for intact skin acetophenon is non irritating.

No classification according to EU criteria is expected as mean irritation scores for erythema or edema with maximal scores of 1.0 for intact skin were significantly below the critical value of 2.0 even under the conditions of this test with a prolonged contact time of 24 hrs instead of 4 hrs.