Considering the furor raised about using animals for testing, are there alternatives to using such testing? What are the main tests that use animals and alternatives that would achieve similar results? There is a lot of controversy about using animals to test cosmetics. Animal rights organizations feel that it is unnecessary and uncalled for. The Food and Drug Administration have no law that cosmetics have to be tested on animals.
The main reason cosmetic companies continue to use animals to test their products instead of the alternatives is because they are afraid of getting laws suites. The alternatives to animal testing have not yet been validated, therefore if they were taken to court they may not win the case if these alternatives were used. If companies would recognize the consistency and validity of these products then maybe animal testing will not be needed. Two of the main tests that companies use are the Draize Test and the Irritancy Test. These tests are not needed because there are other tests that don’t use animals and give the same if not better results.
The Draize Test is used to measure the harmfulness of the ingredients that are in cosmetics and household products. The test involves dripping the substance into a rabbit’s eye and recording the results. Scientists use rabbits because they have large eyes and no tear ducts to wash away the chemical. Reactions vary from slight irritation to ulceration and complete blindness.
The rabbits are restrained to keep from clawing their eyes. All of the animals are usually killed at the end of the test, or “recycled” into toxicity tests. R. Sharpe writes in his book, The Cruel Deception: The Use of Animals in Medical Research, the Draize Test should not be used because there are a number of differences between the human eye and the rabbit eye. Rabbits have a third eyelid, they have less tear fluid to wash away irritants, they have a more alkaline eye (humans have a pH of 7.1-7.3, rabbits have a pH of 8.2), and rabbits have a thinner cornea.
Overall the Draize Test overestimates how irritating a product is to the human eye because rabbits eyes are more sensitive than the human eye (Freeberg). This test is also invalid because of the differences in the way the damage is evaluated. In a study performed by Carnegie University of Pittsburgh twelve substances were sent to twenty-four different laboratories. The results that came back for the same substances ranged from mild to severe reactions. Since the test itself is so unreliable companies should look into some alternatives.
An alternative to using animals to test how harmful an ingredient is to the eye is a method called Eytex. Eytex uses a vegetable protein taken from jack beans. This clear protein gel turns clear when it comes in contact with irritating substances. This process is more accurate than the Draize Test is because the “damage” is measured by a spectrophotometer and not estimated by a person. The Eytex Test agrees well with the Draize Test, although the results should be compared to human eye irritation. Until better methods come along this test could be used instead of animals.
The second column shows how closely related Eytex results agreed with Draize Test results, the third column shows what percentage of irritants were identified by Eytex, and the last column shows the number of substances were tested. There is also close agreement between laboratories on the results. One study showed 90% agreement between six different laboratories and ten substances (Kelly). Another study sent sixty substances to twelve different laboratories. In nine of thirteen categories of substances there was 100% agreement between the laboratories. There was 83%-93% agreement between the other four categories (Kelly). This shows that there is more agreement between laboratories in the Eytex Test than the Draize Test.
Another type of test that is used to establish the irritancy of a product is the Skin Irritancy Test. This test measures how a substance irritates the skin. Patches are shaved off the backs of rabbits and slightly abraded to make them more sensitive. The substance is placed on the bare skin and covered with gauze for four hours. Researchers look for signs of redness, inflammation, weeping or scabs (Animal Liberation). These tests have been shown to be invalid.
In one study household products were tested on rabbits, guinea pigs and humans. Only four of the substances were non-irritating to all of the subjects. Twelve were more irritating in one or more of the species and three were less irritating in one or both of the animals than in humans (Nixon). In another study twelve substances were tested on human and rabbit skin, the results were similar only for the two most irritating substances. The remaining ten were irritating to the rabbits but not the humans (Phillips). This shows that rabbits’ skin is also more sensitive than humans.
There are a number of alternatives to this test. They include reconstructed human epidermis, the Microphisometer, and computer modeling. Reconstructed human epidermis is a multi-layered human skin grown in the laboratory and can be used to test skin irritancy. There are different ways to measure the damage an irritating substance causes. Cells can be examined under a microscope, membrane damage can be assessed by leakage of enzymes, or inflammation can be determined by release of interleukins (Animal Liberation).
Whichever method is used, the results can be measured accurately, unlike the skin irritancy tests done on animals where observers estimate the degree of swelling or redness. Results from this test have so far agreed well with animal studies, although ideally they should be compared to human information (Ponec). The microphysiometer is an instrument that detects small changes in the pH of the pH of the cell culture nutrient fluid (changes in lactate, CO2 production). When the microphysiometer measured how munch of a product it took to depress the metabolic rate of human skin by 50% there was very good agreement with animal tests as shown in the table below (Parce).
Chemical Animal Irritancy Microphysiometer
- 1 mild 0.1
- 2 mild 0.5
- 3 moderate-mild 0.7
- 4 moderate-mild 0.8
- 5 moderate-mild 0.9
- 6 moderate 1.7
- 7 severe-moderate 3.9
- 8 severe 4.1
The table shows that the Microphysiometer test rated the irritancy of the eight chemicals in the same order as the animal tests, with the same kind of increase. The final alternative to using animals for skin irritancy testing is computer modeling. Expert computer systems are used to predict the irritancy of new substances based on what is already known about substances with a similar chemical structure. This approach is called Quantitative Structure-Activity Relationship. (Animal Liberation). This system is very reliable. A New York company called Health Designs shows that computer modeling distinguished severe irritants from others in 91.5% of the cases. It distinguished non-irritants from others in 93% of the cases (Sharpe).
Animal testing has brought about many discoveries and cures for many diseases, but in the case of household products and cosmetics animals are not needed. There are many alternatives that are being used, and should be used by all companies. Steps need to be taken to validate these alternatives so cosmetic companies will have no dought about using these alternative methods instead of using animals. Steps can be taken toward ending animal testing for cosmetics by refusing to buy anything that was tested on animals and writing to the companies insisting that they end the testing. No one person can do it alone, but together as a whole it can come to an end.
- Sharp R, The Cruel Deception: The use of Animals in Medical Research, Wellinborough: Thorsons Publishing Group, 1988
- Freeberg F, Griffith J, Bruce R & Bay P, “Correlation of animal test methods with human experience for household products”, Journal of Toxicology – Cutaneous Toxicology, 184, vol 1 (53-64)
- Philips L, Steinberg M, Maibach H & Akars W, “A comparison of rabbit and human skin response to certain irritants”, Toxicology and applied Pharmacology, 1972, vol 21 (369-382)
- Nixon G, Tyson C & Wertz W, “Interspecies comparisons of skin irritancy”, Toxicology and applied Pharmacology, 1975, vol 31 (481-490)
- Kelly C, “An in vitro method of predicting ocular safety”, Drug and Cosmetic Industry, September 1988 (54-64)
- Ponce M, “Reconstructed human epidermis in vitro: an alternative to animal testing”, Alta, 1995, vol 23 (97-110)