March 6, 2013
Advanced alternative, non-animal testing approaches represent the very latest techniques that science has to offer to ensure the safety of new cosmetic products and ingredients. The term "alternative" in the context of animal testing is used to describe any change from present procedures that will result in:
- the replacement of animals,
- a reduction in the numbers used, or
- a refinement of techniques to alleviate or minimize potential pain, distress, and/or suffering.
This is known as the "3Rs" principle.
Some simple animal tests can be replaced by a single cell culture alternative using a 1:1 approach. For example, the "3T3 Neutral Red Uptake" test using mouse cells has been accepted as a replacement for the use of animals to detect sunlight-induced "photo"-toxicity, and 3-dimensional reconstructed human skin models such as EpiDerm™ can replace rabbits in testing for skin corrosion and skin irritation.
However, replacement of more complex tests that take account of potential effects on the whole body requires an "integrated testing strategy" approach using combinations of molecular, genetic, cell and tissue tests together with computer modeling to extrapolate toxic effects seen at the cell level to a whole-body scenario.
Another replacement approach is to "waive" the requirement to conduct new animal testing because, e.g., the levels of anticipated human exposure to a chemical are below what is considered a significant health risk, or because information on a similar chemical can be used to predict the likely effects of the chemical in question.
Validation & regulatory acceptance
Government authorities and companies will accept alternative testing methods only after they have been scientifically "validated," i.e., shown to be relevant for their intended purpose (e.g., identifying chemicals that can irritate the skin or eyes) and able to produce consistent results within and between laboratories. Criteria and processes for test method validation have been developed by regional Centres for the Validation of Alternative Methods (CVAMs) in Europe, the United States, Japan, Korea and Brazil, and at the global level through the Organization for Economic Cooperation and Development (OECD).
The process of validation and regulatory acceptance is slow and expensive—sometimes requiring more than 10 years and millions of dollars for a single alternative method. However, once an alternative method has been accepted as an official OECD Test Guideline, all OECD member countries (currently numbering 34) and adherents to its policy on "mutual acceptance of data" are required to accept the results of the test without question.
The road to full replacement
Imagine a world where lab rats are replaced by lab robots, with high-tech computer models instead of lethal tests on animals. It's not science fiction—it's the vision of "21st century toxicology" articulated the U.S. National Research Council and echoed by science leaders from around the world.
Instead of observing signs of severe sickness or death in chemically overdosed animals, a totally new approach to safety testing is being developed based on an understanding of how chemicals can disrupt normal functions in the human body at the cellular level.
To accomplish this, scientists divide the human body according to its various cell types (brain, skin, lung, liver, etc), and each of these cell types is then individually tested in tissue culture systems. Then, to reconstruct the whole body scenario again, cutting-edge computer models are used to relate the results of numerous different cell and genetic tests to expected real-world conditions for a living, breathing human being.
This sophisticated new approach has the potential to produce results that are more relevant to humans in much less time and at lower cost than is possible with animal testing. And with better information comes improved human health and consumer protection—a win-win for everyone.