Tris(2,4-ditert-butylphenyl) phosphite

Endpoint summary

Description of key information

The substance was not sensitising in guinea gips. 

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:

1979-05-28 - 1979-07-24

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Deviations:

yes

Remarks:

Light period of 10 hours light. incomplete series of induction in test and control groups.

GLP compliance:

no

Type of study:

Maurer optimisation test

Justification for non-LLNA method:

Currently no LLNA study is available for assessment. Guinea Pig optimization tests like the Maurer optimization test has been carried out as an animal test to predict human sensitization for over a decade and is recommended by international test guidelines.

Species:

guinea pig

Strain:

other: Pirbright white

Sex:

male/female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Bantin and Kingman Ltd. Grimston, Hull, England
- Weight at study initiation: 380 - 500 g
- Housing: individually in Macrolon cages, type 3
- Diet (e.g. ad libitum): ad libitum, standard guinea pig pellets (NAFAG, No. 830, Gossau SG)
- Water (e.g. ad libitum): ad libitum

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 ± 2
- Humidity (%): 55 ± 10
- Photoperiod (hrs dark / hrs light): 14 / 10

Route:

intradermal

Vehicle:

other: 70 % propylene glycol in saline (induction and challenge) and Petrolatum (rechallenge)

Concentration / amount:

0.1%

No.:

#1

Route:

intradermal

Vehicle:

other: 70 % propylene glycol in saline (induction and challenge) and Petrolatum (rechallenge)

Concentration / amount:

0.1%

Day(s)/duration:

on Day 35, duration 24h

No.:

#2

Route:

epicutaneous, occlusive

Vehicle:

other: 70 % propylene glycol in saline (induction and challenge) and Petrolatum (rechallenge)

Concentration / amount:

0.1%

Day(s)/duration:

On day 45; duration 24h

No. of animals per dose:

10 males and 10 females

Details on study design:

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: 10
- Exposure period: -
- Test groups: test substance + vehicle (first week) and test substance + vehicle:FCA (1:1) (second and third week)
- Control group: vehicle
- Site: right flank and back
- Frequency of applications: every second day (except weekends)
- Duration: 0-21 d- Concentrations: 0.1 %

B. CHALLENGE EXPOSURE
- No. of exposures: 2
- Day(s) of challenge: 35 and 45
- Exposure period: -
- Test groups: test substance
- Control group: test substance
- Site: left flank
- Concentrations: 0.1 %
- Evaluation (hr after challenge): 24

Positive control substance(s):

no

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Dose level:

0.1%

No. with + reactions:

3

Total no. in group:

19

Clinical observations:

one animal (male) died

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

0.1 %

No. with + reactions:

10

Total no. in group:

19

Clinical observations:

one animal (male) died

Reading:

rechallenge

Hours after challenge:

24

Group:

negative control

Dose level:

0.1%

No. with + reactions:

0

Total no. in group:

19

Clinical observations:

none

Reading:

rechallenge

Hours after challenge:

24

Group:

test chemical

Dose level:

0.1 %

No. with + reactions:

0

Total no. in group:

18

Clinical observations:

one animal (female) died

Interpretation of results:

GHS criteria not met

Remarks:

Migrated information

Conclusions:

The test substance was found to be devoid of skin-sensitizing (contact allergenic) potential in albino guinea-pigs.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

Test substance was evaluated for its sensitizing potential in Guinea Pigs in the Maurer Optimization test (Ciba 1979). The study was performed prior to GLP requirements, but is reported in adequate detail for assessment. The protocol used is similar to OECD testing guideline 406. It uses an intracutaneous sensitization procedure similar to the method recommended in the "Appraisal of the Safety of Chemicals in Foods, Drugs and Cosmetics" (1959), the US Association of Food and Drug Officials (AFDO). During the induction period the animals received one injection every second day (except weekends) to a total of 10 intracutaneous injections of a freshly prepared 0.1 % suspension in propylene glycol 70 %. One control group was treated with the vehicle alone ("negative control"). Fourteen days after the last sensitizing injection, a challenge injection of 0.1 ml of a freshly prepared 0.1 % suspension in propylene glycol 70 % was administered into the skin of the left flank. Twenty-four hours after each injection during the first week of the induction period and 24 hours after the challenge injection the reactions were recorded. Ten days after the intracutaneous challenge injection a subirritant dose of the test compound was applied epicutaneously under occlusive dressings which were left in place for 24 hours. The substance was found to be non-sensitizing.

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

The available experimental test data are reliable and suitable for classification purposes under Regulation 1272/2008. As a result the substance is not considered to be classified as a skin sensitizer under Regulation (EC) No. 1272/2008. Experimental data regarding respiratory sensitization is not available. Considering the absence of a skin sensitizing potential, a hazard of respiratory sensitization is not expected.