2,4-dimethyl-4-phenyltetrahydrofuran

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

July 1980

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Remarks:

Good documented study, comparable to OECD Guideline 406 implemented in 1992, and conducted according to that describes by Magnusson B. and Kligman A.M. (1969), not GLP

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1980

Report date:

1980

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Deviations:

no

Principles of method if other than guideline:

Good documented study, comparable to OECD Guideline 406 implemented in 1992, and conducted according to that describes by Magnusson B. and Kligman A.M. (1969), not GLP

GLP compliance:

no

Type of study:

guinea pig maximisation test

Justification for non-LLNA method:

According to REACH regulation, in vivo skin sensitisation studies that were warried out or initiated before 10 May 2017 shall be considered appropriate to address this standard information requirement.

Test material

Test material information

Constituent 1

Reference substance name:

2,4-dimethyl-4-phenyltetrahydrofuran

EC Number:

279-967-8

EC Name:

2,4-dimethyl-4-phenyltetrahydrofuran

Cas Number:

82461-14-1

Molecular formula:

C12H16O

IUPAC Name:

2,4-dimethyl-4-phenyloxolane

Test material form:

liquid

In vivo test system

Test animals

Species:

guinea pig

Strain:

Hartley

Sex:

male

Details on test animals and environmental conditions:

TEST ANIMALS
- Male albino guinea pigs of outbred Hartley strain
- Weight: 300-400 g
- Source: Bantin and Kingman, Hull, Yorks
- Housing: Housed in grid-floor cages
- Diet: SGP from Labsure A.F. Limited, Poole, Dorset
- Water: no information
- Lighting cycle: artificial lighting conditions with a 12 hour photo-period

Study design: in vivo (non-LLNA)

Induction

Induction 1

Route:

intradermal

Vehicle:

water

Concentration / amount:

Three pairs of intradermal injections of 0.1 mL with:
- 5% (v/v) test item in water
- 5% (v/v) test item emulsified in FCA
- FCA alone

Day(s)/duration:

Not reported

Adequacy of induction:

other: Preliminary series of injections demonstrated that guinea pigs tolerated this level

Induction 2

Route:

epicutaneous, occlusive

Vehicle:

unchanged (no vehicle)

Concentration / amount:

topical application to the test substance as supplied

Day(s)/duration:

2 days

Adequacy of induction:

non-irritant substance, but skin pre-treated with 10% SDS

Challenge

No.:

#1

Route:

epicutaneous, occlusive

Vehicle:

unchanged (no vehicle)

Concentration / amount:

topical application of the test substance in the undiluted form

Day(s)/duration:

24 hours

Adequacy of challenge:

other: normally sub-irritating dose of the sample

No. of animals per dose:

12 males for treated group and 10 males for negative control group

Details on study design:

PRELIMINARY TESTS (see Table 1):
2 Guinea pigs were tested with a 5% and 1% (v/v) test item in liquid paraffin B.P.
Slight raised reactions were observed for each animal at all concentration.
The concentration of 5% (v/v) was defined as the tolerated concentration for intradermal induction.

MAIN STUDY
12 animals were used in the final assay, which was conducted in three stages as follows:

A. INDUCTION EXPOSURE (INTRADERMAL - PHASE A) See Table 2.
- The fur was removed from the shoulder region of each animal by using electric veterinary clippers, and three injections were made on each side within an area of 2 x 4 cm.
- 3 pairs of intradermal injections of 0.1 mL were performed in the treated group: 2 intradermal injections of Freund’s Complete Adjuvant alone; 2 intradermal injections of the test item in a vehicle (water) and 2 intradermal injections of a the test item emulsified in FCA.

The test substance was suspended at a concentration of 5% (v/v) in both the adjuvant and vehicle (water for Injections B.P.) since a preliminary series of injections demonstrated that guinea pigs tolerated this level.
Immediately before injection, an emulsion of FCA was prepared by gradually blending with an equal volume of Water for injections B.P. A sample of adjuvant containing the test material was similarly emulsified, and the suspension of the product in a vehicle was also prepared.

B. INDUCTION EXPOSURE (TOPICAL - PHASE B) See Table 3.
- Six days after the injections were made, the same area of skin was clipped and the site treated with 10% SLS in petrolatum to enhance sensitisation by provoking a mild inflammatory response.
- 24 hours later an occlusive bandage unit was prepared for each animal as follows: a 6 cm strip of plastic adhesive trap was applied, adhesive side uppermost, to one end of 25 cm length of elastic adhesive bandage (6.4 cm Elastoplast). A 2 x 4 cm of Whatman No.3 filter paper was then placed centrally on the plastic tape and loaded with the test item as supplied. Finally, this was applied to the prepared area of skin and the elastic bandage wound around the torso of the animal to achieve occlusion. The strip was removed after a contact period of 48 hours.

10 control animals were subjected to induction without exposure to the test material.

D. CHALLENGE EXPOSURE: Occluded topical application of a normally sub-irritating dose of the sample, followed by assessment of resultant reactions. See Table 4 and 5.
- The substance was applied in the undiluted form in this stage. This concentration failed to elicit any apparent response in 10 control animals which previously had been subjected to induction without exposure to the test material. Two weeks after the final induction phase, the fur was clipped from the flank of each guinea pig. Occlusive bandage units were prepared in a similar fashion as the Topical induction, except that the test material was applied to a 2 x 2 cm patch of filter paper, overlapped by a 4 cm strip of plastic adhesive tape. Complete occlusion was achieved by means of the elastic bandage as before, but the unit was removed after a contact period of 24 hours in this instance.

EVALUATION OF REACTIONS
Any reaction produced in response to the challenge applications was evaluated 24 hours after removal of the occluded patch, since any irritation caused by the plastic tape would usually have subsided by this time and any allergic reactions would tend to be at a peak. The sites were further examined after an additional 24 hours. Three hours prior to the first reading the test site was clipped and the skin gently cleansed of excess chemical with ether. See additionnal tables below.

Challenge controls:

10 males for negative control group

Positive control substance(s):

no

Results and discussion

Positive control results:

Not reported

In vivo (non-LLNA)

Results

Results 1

Key result

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

100 %

No. with + reactions:

0

Total no. in group:

12

Clinical observations:

None

Remarks on result:

no indication of skin sensitisation

Results 2

Key result

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

100 %

No. with + reactions:

0

Total no. in group:

12

Clinical observations:

None

Remarks on result:

no indication of skin sensitisation

Results 3

Key result

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Dose level:

100 and 50 % in petrolatum

No. with + reactions:

0

Total no. in group:

10

Clinical observations:

None

Remarks on result:

no indication of skin sensitisation

Results 4

Key result

Reading:

2nd reading

Hours after challenge:

48

Group:

negative control

Dose level:

100 and 50% in petrolatum

No. with + reactions:

0

Total no. in group:

10

Clinical observations:

None

Remarks on result:

no indication of skin sensitisation

Results 5

Reading:

1st reading

Group:

positive control

Dose level:

not tested

No. with + reactions:

0

Total no. in group:

10

Remarks on result:

not measured/tested

Any other information on results incl. tables

No discernable skin reactions were observed following the challenge application of the test material. This represents a 0% frequency of response, therefore the product is considered to be a Grade 1 Weak Contact Allergen according to the Maximisation grading system.

 

Table 1. Preliminary investigation to determine tolerated concentrations for intradermal injection (induction phase A)

Guinea pig number	Concentration of test material	Reaction exhibited 7 days following injection
1	5.0 % v/v in liquid paraffin B.P.	Slight raised reaction
	1.0 % v/v in liquid paraffin B.P.	Slight raised reaction
2	5.0 % v/v in liquid paraffin B.P.	Slight raised reaction
	1.0 % v/v in liquid paraffin B.P.	Slight raised reaction

 

Table 2. Effects of intradermal injections (induction phase A) in final assay

Guinea pig number	Group	Reactions exhibited 7 days following injection
3	Test	1. Marked inflammatory reaction at Freund's Adjuvant's sites.
4
5
6
7		2. Slight inflammatory response at test material sites.
8
9
10		3. Marked inflammatory reaction at FCA/test material sites.
11
12
13
14

 

 

Table 3. Effects observed following occluded topical induction (Phase B) in final assay; using 10% SLS in petrolatum as inflammatory agent

Guinea pig number	Reactions exhibited on removal of occlusive units
3	Mild to moderate inflammatory (grade 1-2 according to scale).
4
5
6
7
8
9
10
11
12
13
14

 

Table 4. Determination of concentration for challenge phase (control group)

Guinea pig number	Concentration of test material	Reaction exhibited at
		24 hours	48 hours
15	As supplied	0	0
	50% petrolatum	0	0
16	As supplied	0	0
	50% petrolatum	0	0
17	As supplied	0	0
	50% petrolatum	0	0
18	As supplied	0	0
	50% petrolatum	0	0
19	As supplied	0	0
	50% petrolatum	0	0
20	As supplied	0	0
	50% petrolatum	0	0
21	As supplied	0	0
	50% petrolatum	0	0
22	As supplied	0	0
	50% petrolatum	0	0
23	As supplied	0	0
	50% petrolatum	0	0
24	As supplied	0	0
	50% petrolatum	0	0

 

Table 5. Reactions to challenge applications of test material in final assay (control group)

Guinea pig number	Concentration of test material	Reaction exhibited at
		24 hours	48 hours
3	As supplied	0	0
4	As supplied	0	0
5	As supplied	0	0
6	As supplied	0	0
7	As supplied	0	0
8	As supplied	0	0
9	As supplied	0	0
10	As supplied	0	0
11	As supplied	0	0
12	As supplied	0	0
13	As supplied	0	0
14	As supplied	0	0

Sensibilisation rate: 0%

Garde: I

Classification: Weak contact allergen - not classified under CLP and GHS

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

Under the test conditions, test substance is not classified as sensitiser according to the criteria of the Regulation EC No. 1272/2008 (CLP) and of the GHS.

Executive summary:

In a comparable Magnusson & Kligman maximisation study performed with similary to OECD Guideline 406, Guinea pigs were treated as follows:

After induction (intradermic injection at 5% and topical application at 100%) of 12 Guinea Pigs of treated group with the test substance, the challenge phase, under occlusive dressing for 24 hours, consisted to a single topical application of the test item at 100%. The test concentrations for the main study were determined from a preliminary study.

 

No discernable skin reactions were observed following the challenge application of the test material. This represents a 0% frequency of response, therefore the product is considered to be a Grade 1 Weak Contact Allergen according to the Maximisation grading system.

 

Under the test conditions, test substance is not classified as sensitiser according to the criteria of the Regulation EC No. 1272 /2008 (CLP) and of the GHS.

This study is considered as acceptable and satisfies the requirement for skin sensitisation endpoint.