The Chemotechnique haptens (incorrectly named allergens from old tradition) can be applied to all types of patch test plasters. However, the test chamber of choice should be made of inert polyethylene plastic. Chemotechnique offers three types of inert test chamber systems, IQ Ultimate™, IQ Ultra™ and IQ Chamber. The IQ Chamber introduced in 1993 is still available.The use of polyethylene plastic is recommended to avoid side reactions caused by material such as aluminum metal. Aluminum can elicit allergic reactions to the material of the test chamber itself as well as catalyze reactions of the test preparation and also absorb the haptens to the surface of the metal.