N-(tert-butyl)benzylamine

Endpoint summary

Description of key information

Nonsensitising in the Buehler assay

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records

Reference

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1987

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

Guideline study using concurrent standards of quality assurance standards

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Qualifier:

according to guideline

Guideline:

EU Method B.6 (Skin Sensitisation)

GLP compliance:

not specified

Type of study:

guinea pig maximisation test

Justification for non-LLNA method:

precedes establishement of LLNA

Species:

guinea pig

Strain:

Dunkin-Hartley

Sex:

female

Details on test animals and environmental conditions:

The animals were housed in suspended cages with wire mesh floors.
They had free access to tap water and a Vitamin C rich Guinea Pig diet. Hay was given once weekly.
Room Temperature: 21 deg C.
Humidity: 30-70%
15 air changes per hour
12 hours of artificial light in every 24 hour period.

Route:

intradermal and epicutaneous

Vehicle:

other: liquid paraffin

Concentration / amount:

1% (v/v) intradermal, with Freund's Complete Adjuvant
20% (v/v) topical

Day(s)/duration:

48 hours

Adequacy of induction:

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

No.:

#1

Route:

epicutaneous, occlusive

Vehicle:

other: liquid paraffin

Concentration / amount:

10% and 5%

Day(s)/duration:

24 hours

Adequacy of challenge:

highest non-irritant concentration

No. of animals per dose:

20 animals were used for induction
10 animals were used as control

Details on study design:

RANGE FINDING TESTS:

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: 2
- Exposure period: 7 days after intradermal injection with FCA
- Test groups: 20 animals
- Control group: 10 animals
- Site: Dorsal skin of scapula
- Frequency of applications: intradermal, 1 topical
- Duration: Topical exposure was 48 hr in duration
- Concentrations: 1% (v/v) intradermal; 20% (v/v) topical

B. CHALLENGE EXPOSURE
- No. of exposures: 1 (2 doses, one on right flank, one on left flank)
- Day(s) of challenge: 14 days after topical exposure
- Exposure period: 24 h
- Test groups:
- Control group: same but without test material
- Site: right and left flanks
- Concentrations: 10% and 5%
- Evaluation (hr after challenge): 24, 48 and 72 hr after removal of patch

A 4 x 6 cm area of dorsal skin on the scapular region of the guinea-pig was clipped free of hair with electric clippers. Three pairs of intradermal injections were made simultaneously into this area as discussed below:
1. Freund's complete adjuvant was diluted with anequal volume of water for irrigation.
2. N-Benzyl-tert-butylamine, 1% v/v in liquid paraffin.
3. N-Benzyl-tert-butylamine, 1% v/v in a 50/50 mixture of Freund’s complete adjuvant and liquid paraffin.

Topical application:
One week after the injections, the same 4 x 6 cm interscapular area was clipped and shaved free of hair. A 2 x 4 cm patch of Whatman No. 3 paper was saturated with N-benzyl-tert-butylamine, 20% v/v in liquid paraffin. The patch was placed on the skin and covered by a length of impermeable plastic adhesive tape {5 cm width “Blenderm”). This in turn was firmly secured by elastic adhesive bandage ("Elastoplast" 5 cm width) wound around the torso of the animal and fixed with “Sleek” impervious plastic adhesive tape. The dressing was left in place for 48 hours.
Control animals:
During the induction period the control animals were treated similarly to the test animals with the exception that the test compound was omitted from the intradermal injections and topical application.

Challenge:
The test and control animals were challenged topically two weeks after the induction period using N-benzyl-tert­butylamine, 10% and 5% v/v in liquid paraffin.
Hair was removed by clipping and then shaving from an area on the left flank of each guinea-pig. A 2x2 cm patch of Whatman No. 3 paper was saturated with approximately 0.2 ml of N-benzyl-tert-butylamine, 10% v/v in liquid paraffin and applied to an anterior site on the flank. N-Benzyl-tert-butylamine, 5% v/v in liquid paraffin was applied in a similar manner a posterior site. The patches were sealed to the flank for 24 hours under strips of “Blenderm” covered by “E lastoplast" wound around the trunk and secured with “Sleek".

Reading the challenge reactions:
The challenge sites were evaluated 24, 48 and 72 hours after removal of the patches. The numerical scores awarded to dermal reactions resulting from the challenge application were recorded.

Challenge controls:

without test material

Positive control substance(s):

not specified

Key result

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

10%

No. with + reactions:

2

Total no. in group:

20

Clinical observations:

Dermal reaction "more marked", definitive positive

Remarks on result:

positive indication of skin sensitisation

N-Benzyl-Tert-Butylamine produced evidence of delayed contact hypersensitivity in two animals. There was no evidence of delayed contact hypersensitivity seen in eighteen animals. The test substance is evaluated as not sensitising.

Interpretation of results:

GHS criteria not met

Conclusions:

In a maximization protocol in guinea pigs, the test substance was determined not to be sensitising. The criteria for classification for the sensitisation endpoint is not met.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

An in vivo study by the Buehler method in guinea pigs shows that the substance is nonsensitising. Criteria for classification is not met and the substance is not classified.