Isononyl acetate

Endpoint summary

Description of key information

Skin sensitization:

A Human maximisation test was carried out in 26 volunteers to determine skin sensitization potential caused by the chemicalIsononyl acetate (CAS No: 40379-24-6). Each subject was treated with 4% of Isononyl acetate in petrolatum dermally and later observed for any signs of contact allergy. None of the volunteer showed any signs of contact sensitization. Hence the chemical Isononyl acetate (CAS No: 40379-24-6) wasconsidered to be not sensitizing to the skin of human volunteers and can be classified under the category ˋ Not Classified’ as per CLP regulation.

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:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Justification for type of information:

Data is from peer reviewed journal.

Qualifier:

according to guideline

Guideline:

other: as mentioned below

Principles of method if other than guideline:

A Human maximisation test was carried out in 26 volunteers to determine skin sensitization potential caused by the chemical Isononyl acetate (CAS No: 40379-24-6).

GLP compliance:

not specified

Type of study:

other: Human maximisation test

Justification for non-LLNA method:

not specified

Specific details on test material used for the study:

- Name of test material (IUPAC name): - 3,5,5-trimethylhexyl acetate
-Common name: Isononyl acetate
- Molecular formula : C11H22O2
- Molecular weight : 186.293 g/mol
- Smiles notation : C(C)(=O)OCCCCCCC(C)C
- InChl : 1S/C11H22O2/c1-10(2)8-6-4-5-7-9-13-11(3)12/h10H,4-9H2,1-3H3
- Substance type: Organic
- Physical state: Liquid

Species:

other: Human

Strain:

other: Not applicable

Sex:

not specified

Details on test animals and environmental conditions:

not specified

Route:

intradermal and epicutaneous

Vehicle:

petrolatum

Concentration / amount:

4%

Day(s)/duration:

not specified

Adequacy of induction:

not specified

No.:

#1

Route:

epicutaneous, occlusive

Vehicle:

petrolatum

Concentration / amount:

4%

Day(s)/duration:

not specified

Adequacy of challenge:

not specified

No. of animals per dose:

26

Details on study design:

No data available

Challenge controls:

No data available

Positive control substance(s):

not specified

Key result

Reading:

1st reading

Group:

test chemical

Dose level:

4%

No. with + reactions:

0

Total no. in group:

26

Clinical observations:

No signs of sensitization were observed.

Remarks on result:

no indication of skin sensitisation

Cellular proliferation data / Observations:

No signs of sensitization were observed.

Interpretation of results:

other: not sensitizing

Conclusions:

The test material Isononyl acetate (CAS No: 40379-24-6) was considered to be not sensitizing to the skin of human volunteers.

Executive summary:

A Human maximisation test was carried out in 26 volunteers to determine skin sensitization potential caused by the chemical Isononyl acetate (CAS No: 40379-24-6).

 

Each subject was treated with 4% of Isononyl acetate in petrolatum dermally and later observed for any signs of contact allergy.

 

None of the volunteer showed any signs of contact sensitization. Hence the chemical Isononyl acetate (CAS No: 40379-24-6) was considered to be not sensitizing to theskin of human volunteers.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

Skin sensitization

Various studieshas been investigated for the test chemicalIsononyl acetate (CAS No: 40379-24-6)to observe the potential for skin sensitization to a greater or lesser extent. The studies are based on in vivo experiments in guinea pigs and humans for target chemicalIsononyl acetate (CAS No: 40379-24-6) and its structurally similar read across substancesIsoamyl salicylate(CAS No: 87-20-7) and Isoamyl Propionate (CAS No: 105-68-0).The predicted data usingQSAR toolbox and Danish QSAR databasethe has also been compared with the experimental data and summarized as below;

 

A maximization tests of target chemical Isononyl acetate (CAS No: 40379-24-6) were carried out by D. L. J. Opdyke (1979) on human volunteers. The first study was conducted on 26 volunteers. The material was tested at a concentration of 4% in petrolatum and did not produce any sensitization reactions. In a second maximization test, carried out on 25 volunteers, the material was tested at a concentration of 4% in petrolatum and produced one sensitization reaction among the 25 subjects tested. An additional maximization test was carried out on 24 volunteers, using a concentration of 4% in petrolatum and produced no sensitization reactions. Since skin sensitizing effects were not observed in treated volunteers, the chemical Isononyl acetate (CAS No: 40379-24-6) was considered to be not sensitizing.

The skin sensitization potential of Isononyl acetate (CAS No: 40379-24-6) was estimated using OECD QSAR toolbox version 3.3 with log Pow as the primary descriptor. The substance Isononyl acetate (CAS No: 40379-24-6) was estimated to be not sensitizing to the skin of Dunkin-Hartley guinea pigs. Based on the estimated result Isononyl acetate (CAS No: 40379-24-6) failed to induce skin sanitization effects and hence is considered to be not sensitizing to Dunkin-Hartley guinea pigs.

 

According to Danish QSAR database , the skin sensitization effects were estimated by using four different models i.e, Battery, Leadscope, SciQSAR and CASE Ultra forchemical Isononyl acetate (CAS No: 40379-24-6). Based on estimation, no skin sensitization reactions were observed in guinea pigs and humans. Therefore,Isononyl acetate (CAS No: 40379-24-6) was considered to be not sensitizing.

 

The above results were supported by the experimental study conducted by A. Lapczynski, L. Jones, D. McGinty, S. Bhatia, C.S. Letizia, A.M. Api (2007) forstructurally similar read across substanceIsoamyl salicylate(CAS No: 87-20-7) in 5 guinea pigs by using Closed Epicutaneous Test (CET). During induction phase, the test material applied on the nape using Torii’s patch plaster and adhesive tape at concentration of 30% for 48 hours exposure period.Induction applications were made 3 times per week for two weeks. After a 2-week rest period, a 48-h occluded challenge application with 1% isoamyl salicylate was made to the clipped, shaved flank using Finn Chambers and adhesive tape. Skin was evaluated at 24 and 48 h after patch removal. Since no known skin reactions were observed, Isoamyl salicylate(CAS No: -87-20-7) can be concluded as non sensitizing to guinea pigs.

 

The above studies were further supported by an Open Epicutaneous Test (OET) performed on guinea pigs by G. Klecak (1985) for structurallysimilar read across substanceIsoamyl Propionate (CAS No: 105-68-0). On day 1 during induction, 0.1 ml of the 2-phenylethyl propanoate was applied at concentrations of 100%, 30%, 10%, 3%, 1%, or 0.3% in vehicle to an area measuring 8 cm2 on the clipped flank skin of the guinea pigs. The applications are repeated daily for 3 weeks or done 5 times weekly during 4 weeks, usually on the same skin sites. The application sites were left uncovered and the reactions, if continuous daily applications were performed, can be read 24 h after each application, or at the end of each week. To determine whether or not contact sensitization was induced, all groups of guinea pigs previously treated for 21 days, as well as 10 untreated, or only pretreated with the vehicle, controls are tested on days 21 and 35 on the contralateral flank with the test material. This test was performed by applying with a pipette 0.025 ml of each concentration to skin areas measuring 2 cm2. The reactions were read after 24, 48 and/or 72h. None of the treated guinea pigs showed any signs of skin sensitization at challenge concentration of 4%.Thus the chemical Isoamyl Propionate (CAS No: 105-68-0) was considered to be not sensitizing on skin of guinea pigs in an Open Epicutaneous Test (OET).

 

Based on the available data for the target chemical, supporting studies and read across substance,it can be concluded thatchemical Isononyl acetate (CAS No: 40379-24-6) is unable to cause skin sensitization and considered as not sensitizing.Comparing the above annotations with the criteria of CLP regulation, it can be classified under the category “Not Classified”.

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

The skin sensitization potential of test substance Isononyl acetate (CAS No: 40379-24-6) and its structurally similar read across substances Isoamyl salicylate (CAS No: 87-20-7) and Isoamyl Propionate (CAS No: 105-68-0) were observed in various studies. From the results obtained from these studies it is concluded that the chemical Isononyl acetate (CAS No: 40379-24-6) is not likely to cause skin sensitization and hence can be classified as non skin sensitizer.