3-amino-2-chlor-6-methylphenol

Additional toxicological data

Administrative data

Endpoint:

additional toxicological information

Type of information:

experimental study

Adequacy of study:

other information

Study period:

04.03.2011 - 16.02.2012

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: OECD 428: Skin Absorption: In Vitro Method

GLP compliance:

yes (incl. QA statement)

Test material

Specific details on test material used for the study:

Unlabelled test material:
3-amino-2-chloro-6-methylphenol

Radiolabelled test material:
Name: [14C]-labelled test substance (test item)
Chemical name: 5-Amino-6-chloro-o-cresol, [U-^14C]-phenol
Molecular mass: 159.6 g/mol at 2294 MBq/mmol
Purity: 99 % (HPLC)
Appearance: Pale pink solid

Applicant's summary and conclusion

Executive summary:

The test substance, A094, is intended to be used as an ingredient in hair dye formulations.  As part of the safety evaluation of this ingredient, a study was required to assess the extent of its dermal bioavailability following topical application of three formulations, with radiodiluted [¹⁴C]-A094 concentrations of 1, 2 and 3% (w/w), to excised dermatomed pig skin.  Immediately prior to application, the formulations were mixed 1:1 (w/w) with developer without hydrogen peroxide (Test Preparations 1, 3 and 5) and with developer with hydrogen peroxide (6%, w/w) (Test Preparations 2, 4 and 6).  The final applied concentration of A094 in Test Preparations 1 and 2 was 0.5% (w/w).  The concentration of A094 in Test Preparations 3 and 4 was (1.0%, w/w).  The concentration of A094 in Test Preparations 5 and 6 was 1.5% (w/w).  The skin surface was washed at 30 min, for each test preparation, to reflect the in-use conditions.  The skin was again washed at 24 h post dose as a final wash off before test run termination.

Previously frozen dermatomed pig skin (12 replicates per test run of 4 individual pigs in total) was mounted into static diffusion cells containing receptor fluid (phosphate buffered saline, ca 10 mL) in the receptor chamber. The skin surface temperature was maintained at 32°±1°C throughout the experiment. An electrical resistance barrier integrity test was performed and any pig skin sample exhibiting a resistance <4 kΩ was excluded from subsequent dermal bioavailability measurements.

The hair dye formulation was applied at an application volume of ca 20 mg/cm², to dermatomed pig skin mounted into static diffusion cells in vitro.

Dermal bioavailability was assessed by collecting receptor fluid aliquots at 0.5, 1, 2, 4, 6 and 24 h post dose. At 30 min post dose, for both test preparations, exposure was terminated by washing the skin surface with a mild shampoo solution and drying the skin surface with tissue paper (tissue swabs). At 24 h post dose, the washing procedure was repeated. The skin was then removed from the static diffusion cells, dried and divided into exposed and unexposed skin. The stratum corneum was removed from the exposed skin with 20 successive

D-Squame® discs. The exposed and unexposed skin was solubilised with Solvable® tissue solubiliser.  Bulk receptor fluid was removed from the receptor chamber and retained for future interest.  All samples were analysed by liquid scintillation counting.