1,1'-[methylenebis(oxy)]dibutane

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2002

Report date:

2002

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of study:

guinea pig maximisation test

Justification for non-LLNA method:

Study report was available before entry into force of REACH regulation

Test material

Test material information

Constituent 1

Reference substance name:

1,1'-[methylenebis(oxy)]dibutane

EC Number:

219-909-0

EC Name:

1,1'-[methylenebis(oxy)]dibutane

Cas Number:

2568-90-3

Molecular formula:

C9H20O2

IUPAC Name:

1-(butoxymethoxy)butane

Details on test material:

- Name of test material (as cited in study report): Butylal
- Physical state: Colourless liquid
- Analytical purity: > 99.99%
- Impurities (identity and concentrations): Formaldehyde (0.0038% w/w), water (not detected), n butanol (not detected).
- Composition of test material, percentage of components: Formaldehyde (0.0038% w/w), water (not detected), n butanol (not detected), butylal (>99.99% w/w)
- Lot/batch No.: E971205
- Expiration date of the lot/batch: No expiry date
- Storage condition of test material: at room temperature and protected from light

In vivo test system

Test animals

Species:

guinea pig

Strain:

Dunkin-Hartley

Sex:

male/female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Charles River France, 76410 Saint-Aubin-lès-Elbeuf, France
- Age at study initiation: three months
- Weight at study initiation: 388 ± 16 g for the males and 362 ± 15 g for the females
- Housing: housed individually in polycarbonate cages (48 cm x 27 cm x 20 cm) equipped with a polypropylene
bottle. Dust-free sawdust was provided as litter (SICSA, 92142 Alfortville, France).
- Diet (e.g. ad libitum): free access to "106 pelleted diet" (UAR, 91360 Villemoisson-sur-Orge, France).
- Water (e.g. ad libitum): Drinking water filtered by a F.G. Millipore membrane (0.22 micron) was provided ad libitum.
- Acclimation period: at least 5 days before the beginning of the study

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21 ± 2°C
- Humidity (%): 30 to 70%
- Air changes (per hr): approximately 12 cycles/hour of filtered, non-recycled air
- Photoperiod (hrs dark / hrs light): 12 h/12 h

IN-LIFE DATES: From: 19/02/1998 To: 30/03/1998

Study design: in vivo (non-LLNA)

Induction

Induction 1

Route:

intradermal and epicutaneous

Vehicle:

paraffin oil

Induction 2

Concentration / amount:

10% (w/w) intradermal route
100% cutaneous route

Challenge

Challenge 1

Route:

epicutaneous, occlusive

Vehicle:

paraffin oil

Challenge 2

Concentration / amount:

10% (w/w) intradermal route
100% cutaneous route

No. of animals per dose:

10 males and 10 females

Details on study design:

RANGE FINDING TESTS:

By intradermal route:
. 24 hours before treatment, the dorsal region of the animals was clipped,
. intradermal administrations of the test substance formulation (0.1 ml) at different
concentrations were performed in the interscapular region,
. cutaneous reactions were evaluated approximately 24, 48 hours and 6 days after the
injections.

By cutaneous route:
. 24 hours before treatment, both flank regions of the animals were clipped,
. 0.5 ml of the undiluted test substance or test substance formulation at the chosen
concentrations were placed on a dry gauze pad (approximately 4 cm2) which was then applied
to the skin and held in place by an occlusive dressing for 24 hours,
. cutaneous reactions were evaluated approximately 24 and 48 hours after removal of the
dressings.

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: intradermal: 1 (6 injections). Cutaneous: 1
- Exposure period: cutaneous: 48 hrs
- Test groups: cutaneous: application of 0.5 ml of the undiluted test substance. Intradermal: Three injections of 0.1 ml were made into each side of the interscapular region
- Control group: application of 0.5 ml of the vehicle. intradermal: Three injections of 0.1 ml were made into each side of the interscapular region
- Site: Interscapular area
- Frequency of applications: -
- Duration: -
- Concentrations: 10% (intradermal) and 100% (cutaneous)

B. CHALLENGE EXPOSURE
- No. of exposures: 1
- Day(s) of challenge: on day 22
- Exposure period: 24 hrs
- Test groups: both (control and test)
- Control group: -
- Site: 0.5 ml of the undiluted test substance to the posterior right flank, and 0.5 ml of the vehicle to the posterior left flank.
- Concentrations: 100 %
- Evaluation (hr after challenge): 24

OTHER:

Challenge controls:

On day 22, the animals of both groups received an application of 0.5 ml of the undiluted
test substance to the posterior right flank, and 0.5 ml of the vehicle to the posterior left flank.
This application was performed using a 1 ml plastic syringe (0.01 ml graduations,
Térumo: CML, 77140 Nemours, France). The test substance or the vehicle was placed on a dry
gauze pad (Coopérative Pharmaceutique Française, 77000 Melun, France), which was then
applied to a 4 cm2 (2 cm x 2 cm) clipped area of the skin.
The pad was held in contact with the skin for 24 hours by means of an occlusive, hypoallergenic
dressing (Laboratoires de Pansements et d'Hygiène, 21300 Chenove, France) and an adhesive
anallergenic waterproof plaster (Laboratoire des Professions Médicales, 92240 Malakoff,
France).
On removal of the dressing, no residual test substance was observed.

Positive control substance(s):

no

Results and discussion

In vivo (non-LLNA)

Results

Results 1

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

all

No. with + reactions:

0

Total no. in group:

20

Clinical observations:

none

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: all. No with. + reactions: 0.0. Total no. in groups: 20.0. Clinical observations: none.

Results 2

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

all

No. with + reactions:

3

Total no. in group:

20

Clinical observations:

erythema score of 1 for 3 animals

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: test group. Dose level: all. No with. + reactions: 3.0. Total no. in groups: 20.0. Clinical observations: erythema score of 1 for 3 animals.

Results 3

Reading:

other: 3rd reading

Hours after challenge:

72

Group:

test chemical

Dose level:

all

No. with + reactions:

3

Total no. in group:

20

Clinical observations:

dryness of the skin observed on 3 animals

Remarks on result:

other: Reading: other: 3rd reading. . Hours after challenge: 72.0. Group: test group. Dose level: all. No with. + reactions: 3.0. Total no. in groups: 20.0. Clinical observations: dryness of the skin observed on 3 animals.

Any other information on results incl. tables

No clinical signs and no mortality were observed during the study.

The body weight gain of the treated animals was normal when compared to that of the control animals

On day 10, after the cutaneous application of the induction period, signs of irritation were observed at the interscapular test site in the control and treated groups.

Applicant's summary and conclusion

Interpretation of results:

not sensitising

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

Under our experimental conditions and according to the maximization method of Magnusson and Kligman, the test substance BUTYLAL does not induce delayed contact hypersensitivity in guinea-pigs.

Executive summary:

At the request of Société Lambiotte, Bruxelles, Belgium, the potential of the test substance BUTYLAL to induce delayed contact hypersensitivity was evaluated in guinea-pigs according to the maximization method of Magnusson and Kligman and to OECD (No. 406, 17th July 1992) and EC (92/69/EEC, B6, 31st July 1992) guidelines. The study was conducted in compliance with the principles of Good Laboratory Practice Regulations.

Methods

Thirty guinea-pigs were allocated to two groups: a control group 1 (five males and five females) and a treated group 2 (ten males and ten females).

On day 1, intradermal injections of Freund's complete adjuvant mixed with the test substance (treated group) or the vehicle (control group) were performed in the interscapular region.

On day 7, the same region received a topical application of sodium lauryl sulfate in vaseline (10% w/w) in order to induce local irritation.

On day 8, this same test site received a cutaneous application of the test substance (treated group) or the vehicle (control group) and was then covered by an occlusive dressing for 48 hours.

On day 22, after a rest period of 12 days, all animals of the treated and control groups were challenged by a cutaneous application of the test substance to the right flank. The left flank served as control and received the vehicle only. Test substance and vehicle were maintained under an occlusive dressing for 24 hours. Skin reactions were evaluated approximately 24, 48 and 72 hours after removal of the dressing.

Test substance concentrations were as follows:

Induction (treated group)

⋅ intradermal injections: BUTYLAL at the concentration of 10% (w/w) in paraffin oil

⋅ topical application: BUTYLAL undiluted.

Challenge (all groups)

⋅ topical application: BUTYLAL undiluted.

At the end of the study, animals were killed without examination of internal organs.

No skin samples were taken from the challenge application sites.

The sensitivity of the guinea-pigs in CIT experimental conditions was checked with positive sensitizers DNCB and Mercaptobenzothiazole.

During the induction period, the reference substance DNCB was applied at the concentrations of 0.1% (w/w) (day 1) and 1% (w/w) (day 8). The reference substance Mercaptobenzothiazole was applied at the concentrations of 1% (w/w) (day 1) and 20% (w/w) (day 8).

For the challenge application, the reference substance DNCB was applied at the concentration of 1% (w/w). The reference substance Mercaptobenzothiazole was applied at the concentration of 20% (w/w).

The interpretation of results was carried out according to the classification criteria laid down in Council Directive 93/21/EEC (27th April 1993) adapting to technical progress for the eighteenth time Council Directive 67/548/EEC.

Results

No clinical signs and no deaths were noted during the study.

No well-defined cutaneous reactions were observed after the challenge application.

The species and strain which were used showed a satisfactory sensitization response in 90% animals treated with DNCB and in 30% animals treated with Mercaptobenzothiazole.

Conclusion

Under our experimental conditions and according to the maximization method of Magnusson and Kligman, the test substance BUTYLAL does not induce delayed contact hypersensitivity in guinea-pigs.

According to the classification criteria laid down in Commission Directive 93/21/EEC, the test substance should not be classified as sensitizing to the skin.