Isopropyl benzoate

Endpoint summary

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records

Reference

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1999

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Experiment conducted prior to establishment of guideline; documentation is incomplete but conducted by a reputable industry laboratory.

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay)

Deviations:

no

GLP compliance:

yes

Type of study:

mouse local lymph node assay (LLNA)

Species:

mouse

Strain:

not specified

Sex:

not specified

Details on test animals and environmental conditions:

No environmental conditions data is provided in the study report.

Vehicle:

other: Acetone

Concentration:

3% w/v, 10% w/v and 30% w/v.

No. of animals per dose:

No details

Details on study design:

A sample of Isopropyl Benzoate was assessed for its skin sensitisation potential using the mouse Local Lymph Node Assay. The assay determines
the level of T lymphocyte proliferation in the lymph nodes drainage at the site of chemical application, by measuring the amount of radiolabelled thymidine incorporated into the dividing cells. The test substance was applied as 3%, 10% or 30% w/v preparations in Acetone.

Positive control substance(s):

not specified

Parameter:

SI

Remarks on result:

other: see table below

Parameter:

other: disintegrations per minute (DPM)

Remarks on result:

other: see table below

Concentration of Test Substance CPM / lymph node (xl0 -^2) CPM(counts per minute) Test/control ratio Acetone (control) 0.94 NA 3% w/v 1.42 l.51 10%w/v 2.20 2.34 30% w/v 3.76 4.00

Interpretation of results:

Category 1 (skin sensitising) based on GHS criteria

Remarks:

Migrated information

Conclusions:

IPB is a potential sensitizer in the conditions of the test.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (sensitising)

Additional information:

Isopropyl benzoate is positive in the LLNA, showing an EC3 value of 4.0 when 30% concentration was tested in mice. Stimulation index values were less than 3 when concentrations at or below 10% were tested. This study precedes refinement of the method and establishment of the guideline. In an assay using the Buehler protocol in guinea pigs, undiluted but not a 75% concentration of IPB resulted in sensitisation (15%) of the animals. These data are suggestive of IPB acting as a mild sensitiser in animals. Alkyl benzoate esters, at concentrations up to about 20%, have long been used safely in cosmetic product formulations without reports of dermal sensitisation.

Migrated from Short description of key information:
Isopropyl benzoate is positive in the LLNA and the Buehler protocol in guinea pigs.

Justification for selection of skin sensitisation endpoint:
experimental data

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information:

Migrated from Short description of key information:
No data

Justification for classification or non-classification

As isopropyl benzoate has been demonstrated to induce sensitisation in both the LLNA assay and the Buehler assay, the substance is considered a dermal sensitiser and is classified as Category 1 under Regulation EC No. 1272/2008.