National Toxicology Program

National Toxicology Program

Dermal Test Method Evaluations

Regulatory agencies require testing of 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.

Performance Standards for In Vitro Test Methods for Skin Corrosion

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 performance standards can be used to evaluate the reliability and accuracy of other unvalidated test methods that are based on similar scientific principles and that measure or predict the same biological or toxic effect.

EpiDermTM, EPISKINTM and Rat Skin Transcutaneous Electrical Resistance Assays

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 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.

Corrositex® Assay

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.

Harmonization With International Regulations

The Pipeline and Hazardous Materials Safety Administration of the Department of Transportation, an ICCVAM member agency, announced amendments to the Hazardous Materials Regulations in January 2011. These revisions will maintain alignment with international standards by incorporating various amendments, including changes to proper shipping names, hazard classes, packing groups, special provisions, packaging authorizations, air transport limited quantities, and vessel stowage requirements. These revisions are necessary to harmonize the Hazardous Materials Regulations with recent changes made to the International Maritime Dangerous Goods Code, the International Civil Aviation Organization's Technical Instructions for the Safe Transport of Dangerous Goods by Air, and the United Nations Recommendations on the Transport of Dangerous Goods--Model Regulations.
View final rule announced in Federal Register, January 19, 2011

NTP is located at the National Institute of Environmental Health Sciences, part of the National Institutes of Health.