Use of this information is subject to copyright laws and may require the permission of the owner of the information, as described in the ECHA Legal Notice.
EC number: 813-180-8
CAS number: 5856-32-6
The objective of this study was to
evaluate the potential of the test substance, 12-hydroxystearic acid, to
induce delayed contact hypersensitivity in guinea pigs according to the
maximization method of Magnusson and Kligman and to OECD Guideline 406
(17th July 1992) and Commission Regulation (EC) (No. 440/2008, B.6, 30
May 2008). This study was conducted in compliance with the principles of
Good Laboratory Practice.
A preliminary test was first performed
in order to determine the test item concentrations to be used in the
In the main test, 30 guinea pigs were
allocated to 2 groups: a control group of 5 males and 5 females and a
treated group of 10 males and 10 females.
On Day 1, three pairs of intradermal
injections were performed in the interscapular region of animals:
Complete Adjuvant (FCA) diluted to 50% (v/v) with 0.9% NaCl,
item at the concentration of 2.5% in corn oil (treated group) or vehicle
alone (control group),
item at the concentration of 2.5% in a mixture FCA/0.9% NaCl
(50/50, w/w) (treated group) or vehicle at the concentration of 50%
(w/v) in FCA/0.9% NaCl (50/50, v/v) (control group).
As in the preliminary test, the
highest well-tolerated concentration was shown to be slightly irritant
after topical application, 0.5 mL of sodium lauryl sulfate at 10% (w/w)
in vaseline was applied to the induction site on Day 7 in order to
induce a local irritation.
On Day 8, a filter paper
(approximately 8 cm2) was fully-loaded with the test item at
the concentration of 10% (w/w) in corn oil, and then applied to the
clipped interscapular region, over the intradermal injection sites. The
filter paper was held in place by means of an occlusive dressing for 48
h. The presence of local irritation was checked (but not scored). The
control group animals received an application of the vehicle under the
same experimental conditions.
The induction phase was followed by a
14 day rest period.
On Day 22, all animals of both groups
were challenged by a cutaneous application of the test item at the
concentration of 2.5% (w/w) in corn oil to the right flank. The chamber
was held in contact with the skin by an occlusive dressing for 24 h. The
vehicle was applied to the left flank under the same experimental
Cutaneous reactions were evaluated
before treatment and 24, 48 and 72 h after removal of the dressing.
Each animal was observed at least once
a day for mortality and clinical signs during the treatment and
observation periods. Bodyweight was recorded on Day 1 and at the end of
each observation period.
Upon completion of the observation
period, the animals were sacrificed then discarded without macroscopic post-mortem
examination. For all animals, skin samples of the challenged
application sites were preserved. No microscopic examination was
Results can be summarised as follows:
Mortality, clinical signs and
No unscheduled deaths occurred during
the main test.
No clinical signs indicative of
systemic toxicity were observed in any animals.
The bodyweight change of the treated
animals was similar to that of controls.
At the 24 h reading, after the
challenge application, no cutaneous reaction was observed on the
left flank of control animals (vehicle application). Discrete or
moderate erythema were noted on the right flank (test item-treated) of
5/10 control animals.
In the test item-treated group, at the
24 h reading, a discrete erythema was noted on the left flank (vehicle
treated) of one male only. A discrete or moderate erythema was noted on
the right flank (test item‑treated) of 7/20 animals.
At the 48 h reading, a discrete or
moderate erythema was observed on the left flank of 4/10 control animals
(vehicle application). Discrete or moderate erythema were noted on the
right flank (test substance‑treated) of 6/10 control animals.
In the test substance-treated group,
at the 48 h reading, a discrete erythema was noted on the left flank
(vehicle treated) of 6/20 animals. A discrete or moderate erythema was
noted on the right flank (test substance‑treated) of 9/20 animals.
The increase in the incidence and
severity of cutaneous reactions on both flanks was correlated with the
shaving of the flanks after the 24 h reading.
At the 72 h reading, a discrete
erythema was observed on the left flank (vehicle application) of only
three males of the control group. Discrete or moderate erythema was
noted on the right flank (test substance‑treated) of the same males.
In the test substance-treated group,
at the 72 h reading, a discrete or moderate erythema was noted on the
left flank (vehicle treated) of 5/20 animals. A discrete erythema
sometimes associated with dryness of the skin was noted on the right
flank (test substance-treated) of 6/20 animals.
At each observation time, dryness of
the skin was observed in both group, associated with erythema or not.
It was not possible to determine the
incidence of sensitisation responses in the induced test
substance-treated group as:
the 24 h observation, the shaving of the flanks elicited cutaneous
reactions on the left flank (vehicle treated) of all animals,
skin reactions seen on the right flank (test substance-treated) of the
control group animals were indicative of skin irritation since none of
these animals were exposed to the test substance prior to the topical
The concentration of the test
substance selected for the topical challenge was too high.
Following these observations, it was
therefore not possible to give a clear conclusion on this study.
The potential of the test substance to
induce delayed contact hypersensitivity in guinea pigs remained doubtful.
In order to conclude on the dermal
sensitization potential of the test substance, a further study should be
carried out using a lower concentration for the challenge application.
Information on Registered Substances comes from registration dossiers which have been assigned a registration number. The assignment of a registration number does however not guarantee that the information in the dossier is correct or that the dossier is compliant with Regulation (EC) No 1907/2006 (the REACH Regulation). This information has not been reviewed or verified by the Agency or any other authority. The content is subject to change without prior notice.Reproduction or further distribution of this information may be subject to copyright protection. Use of the information without obtaining the permission from the owner(s) of the respective information might violate the rights of the owner.
På den här webbplatsen används kakor. Syftet är att optimera din upplevelse av den.
Welcome to the ECHA website. This site is not fully supported in Internet Explorer 7 (and earlier versions). Please upgrade your Internet Explorer to a newer version.
Do not show this message again