General safety guidelines are listed for employees of mail centers. Other safe mail handling and safety precautions are listed under the following categories: basic steps to follow when handling mail at work or home and "red flags" for the identification of suspicious letters or packages. Guidelines are provided for what to do if one notices any suspicious or unusual substance on letters or packages, what to do if one suspects that they touched a surface with or were exposed to an unknown substance or powder, and what to do if one notices an unattended letter or package. Information on ricin pertains to its characteristics, where it is found, how it is used, how exposure occurs, whether ricin poisoning can be spread through human contact, and its toxic effects. Also discussed are the dosage required to make a person sick, signs of exposure, and what to do if exposure occurs. Similar information is presented for anthrax. Information on mail bombs pertains to the outward signs that a package may contain a bomb. Also included are a list of questions to ask of a person who phones in a bomb threat and factors to note in the caller's voice, background sounds, and the threat language used by the caller. Other components of this report are a mail center security checklist and information on the work and division locations of the U.S. Postal Inspection Service.