Reaction mass of N,N-dimethyldecan-1-amide and N,N-dimethyloctanamide

Endpoint summary

Description of key information

Skin sensitisation was investigated in a skin sensitisation guinea pig study (Buehler protocol; mixture of dimethylamides). The scores obtained from the study led to no classification for skin sensitisation according to GHS.

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

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study according to Buehler protocol which satisfies the citeria of toxic control act (40 CFR) and the OECD Guideline, GLP, well documented

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Version / remarks:

Conducted to general conditions satisfying the OECD Guideline

GLP compliance:

yes

Type of study:

Buehler test

Justification for non-LLNA method:

Study is from before LLNA test guidelines. Besides, it is clearly demonstrated that irritants and surfactants are more likely to give rise to false positives in the LLNA. Consequently, in the evaluation of such substances for sensitizing properties the LLNA test is not an appropriate assay and would not represent an optimum use of test animals.

Species:

guinea pig

Strain:

Hartley

Sex:

male/female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: approved supplier
- Weight: 374-623g
- Housing: wire mesh suspension cages
- Diet (e.g. ad libitum): ad libitum, PURINA GUINEA PIG CHOW
- Water (e.g. ad libitum): ad libitum
- Acclimation period: at least four days


ENVIRONMENTAL CONDITIONS
- Photoperiod (hrs dark / hrs light): 12h each

Route:

epicutaneous, occlusive

Vehicle:

other: 80/20 ethanol/dest water; acetone

Concentration / amount:

Pilot: 100% (without vehicle), 50%, 25%, 10%, 5%, 2.5%, 1%, 0.5% (partly in 80/20 ethanol/dest water)
Main study Induction: 5% (in 80/20 ethanol/dest water)
Challenge: 2.5% (in acetone)

Route:

epicutaneous, occlusive

Vehicle:

other: 80/20 ethanol/dest water; acetone

Concentration / amount:

Pilot: 100% (without vehicle), 50%, 25%, 10%, 5%, 2.5%, 1%, 0.5% (partly in 80/20 ethanol/dest water)
Main study Induction: 5% (in 80/20 ethanol/dest water)
Challenge: 2.5% (in acetone)

No. of animals per dose:

Main study test group: 10 males and 10 females
Main study control group: 5 males and 5 females

Details on study design:

RANGE FINDING TESTS:
Primary irritation 8 male and 8 female animals were used.

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: 3
- Exposure period: 6h
- Frequency of applications: once a week
- Concentrations: 5%

B. CHALLENGE EXPOSURE
- No. of exposures: 1
- Day(s) of challenge: two weeks after last induction exposure
- Exposure period: 6h
- Test groups: 10 animals per gender
- Control group: 5 animals per gender
- Concentrations: 2.5%
- Evaluation (hr after challenge): 24hr

Challenge controls:

5 animals per gender were used as control, no positive control is reported

Positive control substance(s):

no

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

2.5%

No. with + reactions:

0

Total no. in group:

20

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 2.5%. No with. + reactions: 0.0. Total no. in groups: 20.0.

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

2.5%

No. with + reactions:

0

Total no. in group:

20

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: test group. Dose level: 2.5%. No with. + reactions: 0.0. Total no. in groups: 20.0.

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Dose level:

2.5%

No. with + reactions:

0

Total no. in group:

10

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: negative control. Dose level: 2.5%. No with. + reactions: 0.0. Total no. in groups: 10.0.

Reading:

2nd reading

Hours after challenge:

48

Group:

negative control

Dose level:

2.5%

No. with + reactions:

0

Total no. in group:

10

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: negative control. Dose level: 2.5%. No with. + reactions: 0.0. Total no. in groups: 10.0.

Interpretation of results:

not sensitising

Remarks:

Migrated information

Conclusions:

Only grade ± reactions comparable to the controls were observed. The test substance is considered to be not skin sensitising.

Executive summary:

The potential of the registered substance, as a 5% w/v formulation in 80% ethanol/20% distilled water, to produce delayed contact hypersensitivity in guinea pigs was evaluated using an adaptation of the method of Ritz and Buehler*.

Following primary challenge, there were no grades of 1 produced in the test or control animals. The incidence of grade + responses in the test group (14 of 20) was compared to that of the naive control group (7 of 10). The incidence and severity of these responses in the test group were essentially comparable to those produced by the naive control group indicating that sensitization had not been induced.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

There are valid in vivo data for the assessment of the skin sensitising potential of the registered substance. A study for skin sensitisation using an adaptation of the method of Ritz and Buehler* (Stepan 1990, J.J Kreuzmann) is available.The test substance was used as 5% w/v formulation in 80% ethanol/20% distilled water for induction and as 2.5% formulation in acetone for challenge and epicutanueous occlusive applied to 20 guinea pig. There were no grades of 1 produced in the test or control animals. The incidence of grade + responses in the test group (14 of 20) was compared to that of the naive control group (7 of 10). The incidence and severity of these responses in the test group were essentially comparable to those produced by the naive control group indicating that sensitization had not been induced. Therefore the mixture was classified as not sensitising.

* Study according to Buehler protocol which satisfies the criteria of toxic control act (40 CFR) and the OECD Guideline, GLP.

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

Skin sensitisation:

Skin sensitisation was investigated in a skin sensitisation guinea pig study (buehler protocol; mixture of dimethylamides): The scores obtained from the study led to no classification for skin sensitisation according to GHS (Regulation (EU) 1272/2008) and also to no classification according to EU-criteria DSD (67/548/EEC).

Respiratory sensitisation:

There are no data available for a classification as a sensitizer to respiratory system.

Labelling skin/respiratory sensitisation:

GHS: no classification

DSD: no classification