Most techniques described since the 18th century for the preparation of recent mammal specimens have included preservation of skin, osteological material and parts stored in fluids. Users of collection must be aware of the chemicals and materials employed, which could have an adverse effect either on their research or on their safety. A survey of methods and materials was conducted by examining specimens and literature of the past 2 centuries. The summary is intended to serve as a guide for evaluating the usefulness of specimens for specific research purposes, and for taking precautions when hazardous substances may be present. Over 150 references, appendix with a list of materials.