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Regulatory agencies test
substances for acute skin corrosivity (burns/permanent scarring) and irritation
(reversible skin damage) hazards. Results of these tests are used to label
chemicals so that consumers and workers can take appropriate precautions. Test
results are also used to determine appropriate packaging to minimize potentially
dangerous spills and appropriate procedures to safely handle spills that may
occur during transport.
When conducted on animals, a
test for acute skin corrosivity may cause significant pain and distress. ICCVAM
has conducted independent scientific peer reviews of the usefulness and
limitations of four non-animal (in vitro) corrosivity test methods for
use as alternatives to the in vivo rabbit skin test. Based on these
reviews, ICCVAM recommended that all four methods could be used as part of a
weight-of-evidence approach in an integrated testing scheme for dermal
corrosion/irritation. In this approach, positive in vitro corrosivity
responses do not generally require further testing, and can be used for
classification and labeling without animal testing. ICCVAM is currently involved
in the development of OECD test guidelines for similar methods to be used for
identifying potential skin irritants. Descriptions of these activities and links
to more information can be found below.
Test guidelines by the Organisation for Economic Co-operation and
Development (OECD) are currently under development for the use of in vitro
human skin model systems like EpiDermTM, EpiSkinTM for the identification
of substances with the potential to cause skin irritation. ICCVAM and its Dermal
Corrosivity and Irritation Working Group are participating in the development
of these test guidelines.
At the request of the U.S. EPA, ICCVAM established performance standards for
in vitro test methods for skin corrosion. These performance standards were
based on four in vitro test methods evaluated by ICCVAM for the identification of
substances with the potential to cause skin corrosion. These perforrnance standards
can be used to evaluate the reliability and accuracy of other test methods that are
based on similar scientific principles and that measure or predict the same biological
or toxic effect.
The European Centre for the Evaluation of Alternative Methods (ECVAM) conducted
validation studies of three in vitro methods for dermal corrosivity testing,
EpiDerm, EpiSkin and the rat skin transcutaneous electrical resistance (TER) assay.
ECVAM concluded that these methods were able to distinguish between corrosive and
non-corrosive chemicals for all of the chemical classes considered. In 2000,
subsequent to the ECVAM recommendation, the European Union accepted these methods
for corrosivity testing.
In 2001, ICCVAM conducted an evaluation of the ECVAM studies and all other available
data on these assays, and recommended that they may be used for assessing the dermal
corrosion potential of chemicals in a weight-of-evidence approach in an integrated
testing scheme.
An ICCVAM-sponsored independent Peer Review Panel ("Panel") met in January 1999
to evaluate the Corrositex assay for the identification of potential dermal corrosive
substances. The Panel concluded that for certain testing circumstances Corrositex
is useful as a stand-alone assay for evaluating the corrosivity of acids, bases,
and acid derivatives. In other testing circumstances, and for other chemical and
product classes, the Panel concluded that Corrositex may be used as part of a
tiered assessment strategy. The peer review panel also concluded that Corrositex
offers advantages with respect to animal welfare considerations.
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