Pyrocatechol

Repeated dose toxicity: dermal

Administrative data

Endpoint:

short-term repeated dose toxicity: dermal

Type of information:

experimental study

Adequacy of study:

disregarded due to major methodological deficiencies

Reliability:

3 (not reliable)

Rationale for reliability incl. deficiencies:

significant methodological deficiencies

Remarks:

The test was not performed according to recognised standardised guidelines. Not enough details for assessment.

Data source

Reference

Reference Type:

publication

Title:

Depigmentation of skin with 4-isopropylcatechol, mercaptoamines, and other compounds.

Author:

Bleehen S.S., Pathak M.A., Hori Y., Fitzpatrick T.B.

Year:

1968

Bibliographic source:

The Journal of Investigative Dermatology, 50 (2), 103-117.

Materials and methods

Principles of method if other than guideline:

Depigmentation study

GLP compliance:

no

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Pyrocatechol

EC Number:

204-427-5

EC Name:

Pyrocatechol

Cas Number:

120-80-9

Molecular formula:

C6H6O2

IUPAC Name:

pyrocatechol

Details on test material:

no data

Test animals

Species:

guinea pig

Strain:

other: Black

Sex:

not specified

Administration / exposure

Type of coverage:

not specified

Vehicle:

other: vanishing creams

Details on exposure:

The control area referred to in this publication included unepilated and epilated skin of black guinea pigs. Three different unscented vanishing creams, differing in the pH and the type of emulsifier, were used as placebo. The effects of these mixtures were evaluated in 6 animals. The bases were applicated once daily, five times a week, for a month on the wax-depilated backs of these animals.
Catechol was applied daily, on the wax-depilated backs and the unepilated skin of the ear of black guinea pigs, in concentrations ranging from 1% to 10%. The compounds were applied once daily, five times a week, for periods up to one month. At weekly intervals, the back of each animal was epilated, and the effect of the compound was assessed for the degree of resulting depigmentation and any irritation of the skin.  To evaluate the morphologic changes and the reactivity of the melanocytes 11 animals were tested.

Analytical verification of doses or concentrations:

not specified

Duration of treatment / exposure:

1 month

Frequency of treatment:

5 times a week

Doses / concentrations

Remarks:

Doses / Concentrations:
1%, 3%, 5% 7% and 10% in creams
Basis:
no data

No. of animals per sex per dose:

11 animals treated for the study.

Control animals:

no

Results and discussion

Results of examinations

Details on results:

Absence of depigmentation and irritation at 1%, definite but weak action at 3%, characterised by small spots or speckles of depigmentation, definite but moderate action at 5%, characterised by an uniform hypopigmentation, and a very strong (complete) depigmentation at 7 and 10%.
Catechol was irritating at 7 and 10%.

Effect levels

1

Dose descriptor:

NOAEL

Effect level:

1 other: %

Sex:

not specified

Basis for effect level:

other: Depigmentation

2

Dose descriptor:

LOAEL

Effect level:

3 other: %

Sex:

not specified

Basis for effect level:

other: Depigmentation

Target system / organ toxicity

Critical effects observed:

not specified