Experiments on Animals are scientifically unacceptable - Part 4

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The Draize Test - An Example for the Anatomic, Physiological and Chemical Differences between Animals and Humans.

This is the fourth and final part of a thoroughly elaborated paper documenting that animal experiments are not only unscientific but dangerous to the patient and consumer since these experiments are used to draw false conclusions. Taking the Draize test as an example in which rabbit eyes are used to test irritating chemical substances, Dr.Hartinger proves without a doubt how unnecessary such tests are and how dangerous the effects of such tests are to humans.

The Draize Test

One of the oldest compatibility tests, many times considered inappropriate for humans but still widely used today despite of far better alternative methods, is the Draize test on rabbit eyes.

It was developed in 1944 by John M.Draize, then a toxicologist with the Food and Drug Administration (FDA) in the U.S., to coarsely determine toxic industrial chemicals at workplaces. For this test, usually six albino rabbits are fixed in restraining devices and the substance to be tested is applied into one eyelid of each; painkillers are not administered. After 1, 24, 48 and 72 hours up to 21 days the damages caused to the eye are checked visually and classified on a 4 or 6 step scale.

This contact with highly concentrated, caustic chemical substances results in deep and severe damages to the eye, often in blindness and even death of the animal. It is known that the otherwise rather mute animals often cry out from pain!

Even Draize himself stated that his test was involving quite some problems and not meeting scientific requirements. The chemicals often had an effect in humans completely different from what would be expected according to animal test results. In 1972, Darrol S. Weil and Robert A. Scala, renowned Varbegie Mellon University toxicologists, therefore distributed test substances for comparative result evaluation to 24 different university and state laboratories. The result was a disaster. This method to evaluate the degree of eye irritation in humans which had then been used for 30 years and is still in use today regularly showed different up to completely contrasting results when using the same animal species (26).

The reason for these uselessly varying results from animal to animals mainly lie in the subjectivity of the visual evaluation of the clinical findings and a scale not applied according to uniform guidelines although this doesn't explain the enormous differences in effect up to 100%. That these results cannot be extrapolated to humans has its reasons in the following anatomic, physiological and chemical differences between animals and humans:

1. The rabbit eye has no lacrimal glands as in humans and the pain threshold from damages to the eye is far higher in rabbits. For these two reasons, a rabbit's eye is not cleaned by lacrimal fluid as it is in humans.
2. Contrary to humans, the rabbit eye is provided with a nictitating membrane the reaction of which to the substances used widely varies even from animal to animal.
3. The rabbit's nictitating membrane removes the applied substance in a different way and better than in humans.
4. As a reaction to certain substances a human's outer cornea layer produces so-called vacuoles, but not so the animal.
5. The anterior basal membrane of a human eye is six times thicker.
6. The cornea in a rabbit's eye takes up 25% of the eye surface, in humans only 7%.
7. With 7.1 to 7.3 the pH value of the human lacrimal fluid is significantly lower than that of a rabbit with 8.6.

That Draize test results don't point to the application risk in humans is proven through the surprising professional and legal evaluation of the test results: With the typical test set-up using six rabbits the tested substance is only classified as an irritant if at least two of the animals show irritations to the eye. If, however, only one animal out of six shows symptoms the substance is not considered an irritant!

A great number of substances don't pass the Draize test but are marketed anyway. The cosmetics company Clairol distributes a product although irritations up to permanent damages have been documented. The label reads as follows:

»Caution, this product may not be used to dye eyelashes or eyebrows as this may result in going blind! We recommend immediate medical attention!«

Obviously the risk of product liability is thus legally avoided!

Many producers therefore no longer use or never have used animal experiments. They prefer active ingredients and additives to their products that are known to be and classified as nonharmful. The FDA has a list of these GRAS substances (27).

I may ask for your understanding regarding all these details on test methods based on animal experiments. They are, however, necessary to be able to recognize the many sides of the animal experiment ideology, the practical impossibility of result forecast and extrapolation, the rarely addressed legal background and the trends of the supporters.

Regarding Alternative Methods

It is more than unsatisfactory to only determine that there are so considerable, unpredictable differences between humans and animals concerning effect and compatibility, and incomprehensible that only lately, under the pressure of animal activists for scientific, consumer-related and animal protection reasons alternative methods that provide safe forecasts and extrapolability are investigated with surprising reservedness.

But of what use are the alternative methods elaborated so far, recognized by scientists for a long time to be better, safer and even more precise for humans? They are not used because their validation is being delayed now for years although no single animal experiment has ever been validated. Also, even if approved by law, they are allowed in addition to animal experiments, but there is no requirement for their exclusive use. With the actual still unclear civil right situation whether alternative methods will release the producer in the same way from his responsibility as do animal experiments, and considering the manufacturer's sales interests to other countries, toxicity tests will continue to be widely performed using animals and the LD50 test or its variations. This fact also is clearly known and law offers sufficient possibilities in this respect (28).

These are generally recognized facts which in terms of a balanced consumer information are, however, hardly ever published. This only incomplete insight in the many sides of the problems related to the animal experiment ideology is mean to show that animal activists aren't irrational idealists or even terrorists as heard recently. And this is not about condemning science but about revealing the abuse done in its name - to protect humans, the animals and the environment.

The responsibles' failure lies in the objective-oriented unilateral interpretation of not yet completely resolved biological-phesiological-pathological processes, in the interest based interrelation of politics, economy and science and in the overestimation of the specific knowledge and objectivity of many so-called experts. Without personal liability they promise safety by calculating noncalculating facts of life processes while the application risk is switched to the consumer in an irresponsible manner.

Whoever engages in educating animal and human protection considers all parts of creation as a unity to be protected as a whole with an integrity not to be damaged or destroyed through profit oriented individuals. In his/her PR work, s/he accepts being discredited by those who consider our fellow earthlings and the environment to be mere exploitation objects.

If those supporting animal experiments are right in that humans »are an integrated part of the animal kingdom« and that all the biological reactions found in humans may equally be found in animals because humans are nothing but a further development of the animals, as Darwin said in his evolution theory, then this would be a complete contradiction to the unpredictable differences in effect and compatibility. It is unacceptable to laconically take notice of this fact and accept it by simply shifting the risk to the consumer, and it proves insufficient basic knowledge and misinterpretation.

As long as these contradictions are not resolved and result in severe damages to the consumer because of doubtful theoretical experimental bases, only substances and medications proven non-harmful should be approved. But this will be impossible relying on animal experiments!

Scientists, the economy and authorities are therefore required to elaborate safe test methods using matter insusceptible to pain and to finally introduce and use the alternative methods already existing found by scientists to be more precise. Since experience teaches us that those responsible will not show enough compassion to do without their previous unjustified privileges, a ban of animal experiments in economy and science must be demanded until human and animal health and well-being, for reasons of awareness, are considered superior to economic interests.

More and more news about environmental destruction, toxic damages and animal species extinction are only the tip of the iceberg of a yet unknown dimension and should warn us that such scientifically sanctioned and promoted behavior with an indoctrinated lifestyle will not only make us sick but also destroy any base of our lives.

For ethical and scientific reasons and in the interest of all humans, our fellow earthlings, and the environment the described conditions and consequences of this irresponsible animal experiment ideology should result in a critical assessment of the current situation and in the required rethinking process before it is too late. The pessimistic idea of a known poet better not come true, that for many there will be only one remedy: disaster.

If 150 years ago human medicine research based on the said natural science criteria has chosen animal experiments according to Claude Bernard and his argument: »why think when you can experiment«, then it is high time in the interest of humans and animals to replace such a medicine and attitude that is based on animal experiments and lack of thinking by thinking and doing without animal experiments.

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Übersetzung: © 2003 Beatrice Plamper