Animal toxicity tests are crude, subjectively assessed and the results can vary depending upon the species, age, sex and condition of individual animals. One international study that examined the results of rat and mouse LD50 (Lethal Dose 50%) tests for 50 chemicals found that these tests were able to predict toxicity in humans with only 65% accuracy.
(1) (see page 17) Dr Robert Sharpe, research chemist, states, “The LD50 for digitoxin in rats is 670 times that in cats, whilst for the antifungal substance antimycin, the LD50 in chickens is 30-80 times greater than in pigeons and mallards. The LD50 of thiourea in the wild Norway rat is 450 times greater than in the Hopkin’s strain of rat.” (2)
Manufacturers are simply asked to conduct whatever tests are appropriate, in their opinion, to establish that their cosmetics or household products are safe. Even the environmental conditions in a laboratory can affect results.
The LD50 results for the same chemical can vary widely between different laboratories. It is hardly surprising then to learn that results from animal tests are often difficult to apply to humans. Many substances tested safely on animals have proven to be dangerous to humans and vice versa.
The Real Reasons
Animal tests were crudely developed as long ago as the 1920s and became commonplace in the 1940s. Scientists are familiar and comfortable with the animal-based techniques they have been using for years. It is always difficult to change the status quo. Companies continue to test on animals for legal protection.
Animal testing is designed to protect a manufacturer against legal claims by consumers. The irony is that the defence “we have safety-tested our products on animals” only becomes relevant when that testing fails to detect a potentially dangerous substance and a consumer is injured.
There is no actual legal requirement for animal testing. Manufacturers are simply asked to conduct whatever tests are appropriate, in their opinion, to establish that their cosmetics or household products are safe. The use of animals in laboratories is supported by a very large and powerful industry.
It includes contract testing laboratories, the suppliers of cages, equipment, animals, and infrastructure. Alternatives to animal testing Today, many cosmetic and household product companies have turned their backs on animal testing and begun taking advantage of the many sophisticated non-animal test methods available, which range from cell and tissue cultures to computerised “structure-activity relationship” models. Human cell culture tests have been found to predict toxicity in humans with much greater accuracy than animal tests.
(1) R. Roggeband et al., “Eye Irritation Responses in Rabbit and Man After Single Applications of Equal Volumes of Undiluted Model Liquid Detergent Products,” Food and Chemical Toxicology, 38 (2000): 727-734. (2) Dr Robert Sharpe, “The Cruel Deception”.
Chemical toxicity (poisoning) testing on animals involves subjecting animals to different levels of potentially toxic substances via different routes of exposure in order to assess how and in which way they are affected.Many products are tested to see if they will cause damage to the skin or eyes.
This approach to chemical testing, which uses animals and is mainly observational, subjective and descriptive, is extremely crude. Animal tests tell us little about why a substance is toxic, as the results tend to demonstrate effects rather than causes of toxicity. The test results are difficult to extrapolate from laboratory conditions to real life exposure of humans.
Their credibility is based on established use rather than proven predictive value. Most standard animal tests were developed decades ago and have either never been validated, or have actually failed retrospective validation (for example, the Draize eye test, the Lethal Dose 50% test and carcinogenicity).