2,4,6-tris(dimethylaminomethyl)phenol

Endpoint summary

Description of key information

In a maximisation test according to Magnusson and Kligman (OECD 406) with guinea pigs only mild skin sensitisation was noted which is not sufficient for classification (SafePharm, 1995).

Based on the results of sighting tests, concentrations 0.05 percent w/v for the intradermal induction, 25 percent v/v for the topical induction, and 2 percent and 1 percent v/v for the topical challenge were used. Two animals exhibited very slight erythema at the 2 percent v/v challenge site at the 24-hour observation.

No skin reactions were noted at the 48-hour observation. The test material produced an 11 percent (2/19) sensitization rate. No classification according CLP regulation is necessary because the positive response limit of 30 % is not met.

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records

Reference

Reference 1

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1995-09-04 to 1995-10-05

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

GLP compliance:

yes

Type of study:

guinea pig maximisation test

Justification for non-LLNA method:

A skin sensitization test according to OECD 406 has already excisted since 1995 and is sufficient for evaluation of the skin sensitisation potential of the test substance.

Species:

guinea pig

Strain:

Dunkin-Hartley

Sex:

male

Details on test animals and environmental conditions:

TEST ANIMALS: 
- Strain: Dunkin Hartley guinea pig
- Source: David Hall Limited, Burton-on-Trent, Staffordshire, UK
- Sex: male
- Age: approx. 8 - 11 weeks
- Weight at study initiation: 306 - 401 g
- Acclimatisation: at least 5 days

ENVIRONMENTAL CONDITIONS
- Housing: single or in pairs
- Temperature (°C): 21 - 22 °C
- Humidity (%): 52 - 64 %
- Air changes (per hr): 15 times/hour
- Photoperiod (hrs dark / hrs light): 12 hours
- Diet: Free access (Guinea Pig FD1 Diet, Special Diets Services Limited, Witham, Essex, UK)
- Water: Free access to tap water

Route:

intradermal and epicutaneous

Vehicle:

water

Concentration / amount:

Based on the results of sighting tests, the following concentrations of test item in distilled water were used:
0.05% w/v for the intradermal induction
25% v/v for the topical induction, and
2% and 1% v/v for the topical challenge.

Route:

epicutaneous, occlusive

Vehicle:

water

Concentration / amount:

Based on the results of sighting tests, the following concentrations of test item in distilled water were used:
0.05% w/v for the intradermal induction
25% v/v for the topical induction, and
2% and 1% v/v for the topical challenge.

No. of animals per dose:

Twenty test and ten control animals were used for the main study.

Details on study design:

RANGE FINDING TESTS:
- Selection of Concentration for lntradermal lnduction
Six concentrations of test material were investigated (0.01 %, 0.05%, 0.1 %, 0.5%, 1 % and 5% w/v in distilled water). A total of six guinea pigs were used, each guinea pig receiving four 0.1 ml injections of scale
- Selection of Concentration for Topical lnduction
Two guinea pigs (intradermally injected with Freund's Complete Adjuvant thirteen days earlier) were treated with the undiluted test material and three preparations of the test material (75%, 50% and
25% v/v in distilled water). Applications were made to the clipped flanks under occlusive dressings for an exposure period of 48 hours.
- Selection of Concentration for Topical Challenge
Four preparations of the test material (25%, 10 %, 5% and 2% v/v in distilled water) were applied to the clipped flanks of two guinea pigs under occlusive dressings for an exposure period of 24 hours.


MAIN STUDY
For the purpose of this study the test material was freshly prepared as follows:
lntradermal Induction : 0.05% w/v in distilled water
0.05% w/v in a mixture of Freund's Complete Adjuvant plus distilled water (1:1)
Topical Induction : 25% v/v in distilled water
Topical Challenge : 2% and 1 % v/v in distilled water

- Induction schedule:    
Day 0: Injections  
A row of three injections (0.1 ml each) was made on each side of the mid-line. The injections were:
 a) Freund's Complete Adjuvant plus distilled water in the ratio 1 : 1
b) a 0.05% w/v formulation of the test material in distilled water
c) a 0.05% w/v formulation of the test material in a 1 :1 preparation of Freund's Complete Adjuvant plus distilled water.

Day 2: Assessment for dermal irritation   
Day 7: 48 hours occlusive patch with 0.5 ml of 100 % test substance on  clipped injection sites (control animals: vehicle)   
Day 9: Removal of patch and residual test substance, assessment for  dermal irritation
controls: vehicle instead of test substance
- Challenge schedule:    
Day 21: Two 24 hours occlusive patches (each 0.15 ml) with     (a) 2 % test substance and     (b) vehicle alone on one clipped flank   
Day 22: Removal of patches and residual test substance   
Days 23 and 24: Assessment for challenge reaction 24 and 48 hours after  patch removal

Challenge controls:

The topical applications followed the same procedure as for the test animals except that the vehicle alone was applied to the filter paper.
Skin reactions were quantified as for the test animals.

Positive control substance(s):

no

Key result

Reading:

1st reading

Hours after challenge:

24

Dose level:

2 percent v/v challenge site

No. with + reactions:

2

Total no. in group:

19

Clinical observations:

Two animals exhibited very slight erythema at the 2 percent v/v challenge site at the 24-hour observation. No skin reactions were noted at the 48-hour observation.

Remarks on result:

other: see Remark

Remarks:

Reading: 1st reading. . Hours after challenge: 24.0. Dose level: 2 percent v/v challenge site. No with. + reactions: 2.0. Total no. in groups: 19.0. Clinical observations: Two animals exhibited very slight erythema at the 2 percent v/v challenge site at the 24-hour observation. No skin reactions were noted at the 48-hour observation..

Bodyweight gains of guinea pigs in the test group, between Day 0 and Day 24, were comparable to those observed in the control group animals over the same period.

Conclusions:

Test item has a mild sensitization potential.

Executive summary:

The study was performed to assess the contact sensitisation potential of the test material (Safepharm Standard Method Number OECD 6). Test item was tested for skin sensitization in albino guinea pigs using the Magnusson-Kligman method as per OECD Guideline 406.

 

Twenty test and ten control animals were used for the main study.

 

Based on the results of sighting tests, concentrations 0.05 percent w/v for the intradermal induction, 25 percent v/v for the topical induction, and 2 percent and 1 percent v/v for the topical challenge were used. Two animals exhibited very slight erythema at the 2 percent v/v challenge site at the 24-hour observation.

No skin reactions were noted at the 48-hour observation. The test material produced an 11 percent (2/19) sensitization rate and was classified as a mild sensitizer to guinea pig skin.

Reference 2

Endpoint:

skin sensitisation: in vitro

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

other:

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

Based on the results of the in vivo skin sensitisation study the test item has a mild skin sensitization potential which is not sufficient for classification and labelling according to CLP regulation.

(Remark: The test material produced an 11 percent (2/19) sensitization rate. No classification according CLP regulation is necessary because the positive response limit of 30 % is not met.)