β-methyl-3-(1-methylethyl)benzenepropanal

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1988

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1988

Report date:

1988

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

EU Method B.6 (Skin Sensitisation)

GLP compliance:

yes

Type of study:

guinea pig maximisation test

Justification for non-LLNA method:

Study already available

Test material

Test material information

Constituent 1

Reference substance name:

β-methyl-3-(1-methylethyl)benzenepropanal

EC Number:

412-050-4

EC Name:

β-methyl-3-(1-methylethyl)benzenepropanal

Cas Number:

125109-85-5

Molecular formula:

C13H18O

IUPAC Name:

3-[3-(propan-2-yl)phenyl]butanal

Test material form:

liquid

Specific details on test material used for the study:

Batch Number 8906-87
Purity 95.4%

In vivo test system

Test animals

Species:

guinea pig

Strain:

Himalayan

Remarks:

Himalayan white spotted guinea pigs (outbred)

Sex:

male/female

Details on test animals and environmental conditions:

Standard laboratory conditions:
10-15 air changes
22 +/-3 degrees centigrade
40-70% relative humidity
12 hours fluorescent light/12 hours dark
Music/light period

Study design: in vivo (non-LLNA)

Induction

Induction 1

Route:

intradermal

Vehicle:

other: ethanol

Concentration / amount:

0.5%

Day(s)/duration:

D1

Adequacy of induction:

highest concentration used causing mild-to-moderate skin irritation and well-tolerated systemically

Induction 2

Route:

epicutaneous, occlusive

Vehicle:

other: Ethanol

Concentration / amount:

50%

Day(s)/duration:

One week after the intradermal induction

Adequacy of induction:

highest concentration used causing mild-to-moderate skin irritation and well-tolerated systemically

Challenge

No.:

#1

Route:

epicutaneous, occlusive

Vehicle:

other: Ethanol

Concentration / amount:

30%

Day(s)/duration:

2 weeks after the epidermal induction

Adequacy of challenge:

highest non-irritant concentration

No. of animals per dose:

10 animals (5 males and 5 females) for the vehicle control group
20 animals (10 males and 10 females) for the test item-treated group

Positive control substance(s):

yes

Remarks:

A control group is teste twice a year as a sensitivity check of the guinea pig strain. The most recent test at the time was run during March 1988.

Results and discussion

Positive control results:

100% of the animal tested were found positive.

In vivo (non-LLNA)

Results

Results 1

Key result

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

30%

No. with + reactions:

1

Total no. in group:

19

Remarks on result:

other: One positive erythema reaction in one animal at 24 hrs after challenge

Results 2

Key result

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

30%

No. with + reactions:

0

Total no. in group:

20

Remarks on result:

no indication of skin sensitisation

Results 3

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Dose level:

30%

No. with + reactions:

0

Total no. in group:

5

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: negative control. Dose level: 30%. No with. + reactions: 0.0. Total no. in groups: 5.0.

Results 4

Reading:

1st reading

Hours after challenge:

24

Group:

positive control

Dose level:

3% DNCB

No. with + reactions:

15

Total no. in group:

15

Applicant's summary and conclusion

Interpretation of results:

not sensitising

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

Giv 82-4130 (Florhydral) is considered to possess no skin sensitizing (contact allergenic) potential in albino guinea pigs.

Executive summary:

A total of 30 male and female outbred Himalayan spotted animals were used. Animals were divided into two groups: test group = 10 males and 10 females; control group = 5 males and 5 females. Animals were 7-8 weeks old and weighed 433-478 grams (males) and 456-499 grams (females). Ethanol was used as a vehicle for the intradermal and epicutaneoues applications. Animals were housed individually in Makrolon type-3 cages. Temperature of the animal room was 22 +/- 3 C with a relative humidity of 40-70% and a 12 hour light/dark cycle, music during the light period. There were 10-15 air changes per hour. Animals received food and water ad libitum. Intradermal injections were made for the first portion of the induction phase of the study. An area of dorsal skin from the scapular region (approximately 6 x 8 cm) was clipped free of hair. Three pairs of intradermal injections (0.1 ml/site) were made at the border of a 4 x 4 cm area in the clipped region as follows: Test group - 1) Freund's complete adjuvant 50:50 with ethanol, 2) test material diluted to 0.5% with ethanol, 3) test material diluted to 0.5% by emulsion in a 50:50 mixture of Freund's complete adjuvant and ethanol; Control group - 1) Freund's complete adjuvant 50:50 with ethanol, 2) Vehicle (ethanol), 3) Freund's complete adjuvant 50:50 with ethanol. On day 7 of the study and approximately 24 hours prior to the epidermal application, the scapular area (approximately 6 x 8 cm) was clipped free of hair. Patches of filter paper (4 x 4 cm) were saturated with 50% test material in ethanol and applied over the injection sites of the test animals. Patches were covered by a strip of aluminum foil and firmly secured by elastic plaster wrapped around the trunk and covered with impervious adhesive tape. Dressings remained in place for approximately 48 hours. The animals of the control group were treated as described above except with the vehicle (ethanol) only. The test and control group animals were challenged 2 weeks after the epidermal induction application. Hair was clipped from a 5 x 5 cm area on the left and right flank of each animal. Two patches (2 x 2 cm) of filter paper were saturated with a) non-irritant concentrations of test material in ethanol, b) with the vehicle only and applied to the a) left flank and b) right flank using the same method as for the epidermal application. The dressings remained in place for 24 hours after which time they were removed. Sites were assessed for erythema and edema immediately, 24, and 48 hours after removal of the dressing, using the following numerical scoring system according to Draize: Erythema and eschar formation: 0 = no erythema, 1 = very slight erythema (barely perceptible), 2 = well-defined erythema, 3 = moderate to severe erythema, 4 = severe erythema (beet redness) to slight eschar formation (injuries in depth); Edema formation: 0 = no edema, 1 = very slight edema (barely perceptible), 2 = slight edema (edges of area well-defined by definite raising), 3 = moderate edema (raised approximately 1 millimeter), 4 = severe edema (raised more than 1 millimeter and extending beyond the area of exposure). The control animals were treated in the same way as the test animals. In addition, observations were made daily for viability/mortality and systemic/local symptoms. Animals were weighed at acclimatization start, start of applicaiton and termination of test. No necropsies were performed

A separate positve control study was conducted with Dinitro-chloro-benzol (DNCB) in Dunkin-Hartley guinea pigs. Induction was 5% DNCB in ethanol and challenge was 3% DNCB in ethanol.

OECD Guidelines for Testing of Chemicals, Section 4: Health Effects No. 406, "Skin Sensitization", adopted May 12, 1981. Directive 84/449, EEC B.6. "Acute Toxicity - Skin Sensitization".

1/20 animals showed positive reations at the 24 hour reading which cleared by the 48 hour reading. Under the conditions of the study, 30% benzenepropanal, .beta.-methyl-3-(1-methylethyl) in ethanol is considered to possess no skin sensitizing potential in guinea pigs. No positive results were observed in the vehicle control group. No second challenge was performed. The positive control 3% DNCB in ethanol showed strong skin sensitizing potential in the guinea pigs.