α,α'-propylenedinitrilodi-o-cresol

Endpoint summary

Description of key information

In a skin sensitization test (BASF, 1959), tt was concluded that the test substance is a skin sensitizer.

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:

1959

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Qualifier:

according to guideline

Guideline:

other: Guinea Pig patch test

Principles of method if other than guideline:

Areas (ca. 25 cm2) on the right and left flank of the guinea pig are shaved and then greased. After 24 hours, the left flank is degreased with ether. A total of ca. 0.1 ml of the test material (20 % solution in acetone) is then applied in three consecutive applications. This application is repeated daily for 10 days, if necessary with larger amounts, until clear signs of irritation are observed on the treated skin area. Treatment is then discontinued until the signs of irritation have subsided (11 days). Both the left and right flank is then shaved again. The previosuly untreated right flank is then degreased with ether 24 hours later and treated once with a 2 % solution (in acetone) of the test substance. The skin reaction is scored 8, 12 and 24 hours after application.

GLP compliance:

no

Type of study:

patch test

Justification for non-LLNA method:

Historical, In vivo study which was conducted before 1st June 2008

Species:

guinea pig

Strain:

not specified

Sex:

not specified

Details on test animals and environmental conditions:

no data

Route:

epicutaneous, open

Vehicle:

other: acetone

Concentration / amount:

20% test substance in acetone

Day(s)/duration:

10

Adequacy of induction:

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

Route:

epicutaneous, open

Vehicle:

other: acetone

Concentration / amount:

2% test substance in acetone

Day(s)/duration:

10

Adequacy of challenge:

highest non-irritant concentration

No. of animals per dose:

10

Details on study design:

Areas (ca. 25 cm2) on the right and left flank of the guinea pig are shaved and then greased. After 24 hours, the left flank is degreased with ether. A total of ca. 0.1 ml of the test material (20 % solution in acetone) is then applied in three consecutive applications. This application is repeated daily for 10 days, if necessary with larger amounts, until clear signs of irritation are observed on the treated skin area. Treatment is then discontinued until the signs of irritation have subsided (11 days). Both the left and right flank is then shaved again. The previosuly untreated right flank is then degreased with ether 24 hours later and treated once with a 2 % solution (in acetone) of the test substance. The skin reaction is scored 8, 12 and 24 hours after application.

Challenge controls:

no data

Positive control substance(s):

not specified

Key result

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

2 %

No. with + reactions:

9

Total no. in group:

10

Clinical observations:

erythema

Remarks on result:

positive indication of skin sensitisation

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Dose level:

2 %

No. with + reactions:

0

Total no. in group:

3

Remarks on result:

no indication of skin sensitisation

Reading:

1st reading

Group:

positive control

Remarks on result:

not measured/tested

Interpretation of results:

sensitising

Remarks:

Migrated information

Conclusions:

Based on the available data, the test substance is considered a Skin sensitiser according to Regulation (EC) No 1272/2008 (CLP).

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (sensitising)

Additional information:

In a skin sensitization test (BASF, 1959), areas (ca. 25 cm2) on the right and left flank of ten guinea pig are shaved and then greased. After 24 hours, the left flank is degreased with ether. A total of ca. 0.1 ml of the test material (20 % solution in acetone) is then applied in three consecutive applications. This application is repeated daily for 10 days, if necessary with larger amounts, until clear signs of irritation are observed on the treated skin area. Treatment is then discontinued until the signs of irritation have subsided (11 days). Both the left and right flank is then shaved again. The previosuly untreated right flank is then degreased with ether 24 hours later and treated once with a 2 % solution (in acetone) of the test substance. The skin reaction is scored 8, 12 and 24 hours after application. In addition, three control animals are also challenged in a similar manner. 9 out of 10 guinea pigs displayed erythema, whereas none of the control animals showed any signs of irritation. It was therefore concluded that the test substance is a skin sensitizer.

In a skin sensitization test (BASF, 1967), areas (ca. 25 cm2) on the right and left flank of ten guinea pig are shaved and then greased. After 4 hours, the left flank is degreased with ether. The test material (20 % solution in acetone) is then applied in three consecutive applications. This application is repeated daily for 10 days (5 days/week), if necessary with larger amounts, until clear signs of irritation are observed on the treated skin area. Treatment is then discontinued until the signs of irritation have subsided (13 days). Both the left and right flank is then shaved again. The previosuly untreated right flank is then degreased with ether 4 hours later and treated once with a 2 % solution (in acetone) of the test substance. The skin reaction is scored 12 hours after application. In addition, three control animals are also challenged in a similar manner. 10 out of 10 guinea pigs displayed erythema, whereas none of the control animals showed any signs of irritation. It was therefore concluded that the test substance is a skin sensitizer.

Further available limited data in guinea pigs (TSCAT, OTS0571642) also showed that the test substance is a skin sensitizer.

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

According to the findings of the available studies, the test substance has to be classified as Skin sensitisation Cat. 1 (CLP). A subcategorization into 1A and 1B is not possible based on the available data.