Come Clean: Skin Irritation and Corrosion Tests FAQs

The Physicians Committee

Come Clean: Skin Irritation and Corrosion Tests FAQs

Come Clean: Skin Irritation and Corrosion Tests FAQs | Come Clean: Skin Irritation and Corrosion Tests Resources for Companies | Commonly Conducted Animal Tests | Come Clean Home

What are the problems with animal testing for cosmetic products?

Millions of guinea pigs, rabbits, rats, and mice continue to be used and killed just to bring the latest variety of lotion or anti-wrinkle skin cream “breakthrough” to store shelves. Animals used in toxicology tests often experience unrelieved pain and distress as a result of confinement in laboratory cages, handling, and exposure to chemical substances. The doses in animal tests are chosen to specifically elicit a toxic effect, so they are almost always 100 to more than 1,000 times higher than the dose to which humans will ever be exposed. Not only is this cruel, scientifically such large doses often overwhelm the animals' systems, making effects seen in the studies not necessarily applicable to human exposure situations.

Each species reacts to cosmetics and cosmetic ingredients differently. Effects seen in animals during tests, such as skin lesions, diarrhea, convulsions, difficulty breathing, or tumor development, aren’t directly applicable to humans, because of metabolic, genomic, and organ system differences between species. Responses often vary greatly between individuals, sexes, and strains of animals. Animal tests are also time consuming and costly, making it difficult to fully test the many different ingredients and formulations developed by the personal care industry.

Why focus on skin irritation and corrosion tests?

While no cosmetic product is required by law to be tested on animals, many cosmetic companies choose to do so. In 2012, PCRM began a survey of U.S. companies that produce cosmetics and personal care products. PCRM requests these companies certify that they do not use or commission animal tests for skin irritation and corrosion for any of their products or the ingredients in them. Nonanimal test methods provide companies with more accurate data on how humans would respond to a product or ingredient versus an animal test. PCRM is focusing on these two skin tests because nonanimal methods exist that have been scientifically an internationally validated by numerous laboratories. This will allow companies to quickly and easily implement the nonanimal methods if they are not already using them.

Are skin irritation and corrosion tests required by law for cosmetic or personal care products?

No. The Food and Drug Administration, which regulates cosmetics and personal care products, requires that companies determine the safety of their products but does not specify that animal testing be conducted. In fact, in 2009 a European Union law went into effect that bans animals from being used for these tests on EU soil. It also bans products from being sold in the EU if these tests were conducted on animals anywhere in the world.

How do animal tests give misleading results? And how are animals currently used in skin testing?

Thomas Hartung, M.D., Ph.D., speaks on the problems of outdated technology in toxicology.

Animal tests are performed using very high doses of chemicals to maximize the likelihood that there will be an effect. This results in misleading information. Humans would never be exposed to such high levels of a chemical in the environment or in the products they use. These misleading results often lead to more animal testing in order to determine whether the animal data is relevant to humans.

Additionally, the skin test—known as the Draize skin test—relies on a very subjective scoring method that can yield inconsistent results even within the same laboratory. John Draize developed the Draize skin test in the 1940s, and the method has been used since without any scientific validation studies. The protocol requires that the animals, usually young adult albino rabbits, are restrained and fully conscious, then the test substance is applied to their shaved skin for a set amount of time (usually four hours). The animal is observed for effects such as rash, inflammation, lesions, or any other signs of skin damage for up to 14 days. The animals are usually killed after the test. No painkillers are provided.

What are some alternatives to the Draize rabbit skin test?

There are several in vitro (cell culture) models available to cosmetic companies right now. These alternatives have undergone rigorous international scientific validation, they are: Corrositex, CellSystem EST1000, SkinEthic, EpiDerm, LabCyte EPI-MODEL24, and EpiSkin. Any of these models can be used instead of an animal test for the types of substances to which it applies.

One of the methods to assess skin corrosion in vitro is Corrositex. Corrositex utilizes a protein membrane instead of skin and is so sophisticated that it can detect the rate at which a chemical would go through the skin, something the rabbit test fails to do.


EpiDerm insert being dosed with a solid test substance.

Photos courtesy of MatTek.

Five reconstructed human epidermis (RhE) models have been validated to assess skin corrosion or irritation: SkinEthic, EpiDerm, CellSystem EST1000, LabCyte EPI-MODEL24, and EpiSkin. These constructs are created from skin cells from plastic surgery leftovers. Scientists grow the cells in vitro and develop multilayered tissues, which are then ready to test the cosmetic ingredients or products for skin irritation. The results of in vitro skin studies are measurable, which is another advantage over the rabbit test, in which rabbits’ injuries are assessed subjectively.

Are there ethical implications in animal testing for cosmetics?

Yes. Despite the questionable information provided by animal tests, millions of animals suffer unalleviated pain and death as a result of testing for these products.

Additionally, the fact remains that there is no scientific reason to conduct the skin irritation and corrosion tests in any animal for cosmetic and personal care products. Numerous nonanimal test methods have been scientifically validated which show that in vitro skin is more predictive of human skin. Given the option between an animal test and a nonanimal test, a nonanimal test should always be conducted—it’s that simple.