A broad dental toxicology screening program has been initiated to develop suitable testing methods for new dental materials or products which presently are not considered as drugs. In the report presented here, 42 materials or products have been included in an acute toxicity screening program for the evaluation of irritancy properties. Depending upon the state of the material or product, one or more testing procedures were employed. These included: (1) implantation in rabbit muscle, (2) a tissue culture test, (3) an intradermal test in rabbits, (4) an eye test in rabbits, and (5) a dermal test in rabbits. With the limited number of materials or products, the most suitable method of testing solids was the implantation method and tissue culture. Tissue culture appeared to be the only useful method for powders while tissue culture and an intradermal test the most suitable method for liquids. Other materials and products will be included using these test procedures to note if one or two might eventually be selected as a preferred method of “irritancy” testing when a large number of materials or products are to be screened for a dental or medical application. The final evaluation of safety for a dental material or product must of course be based upon its intended use.