29 Biosafety Manual work area to avoid walking around with contaminated sharps. Care must be taken not to overfill sharps containers. They are considered full when they are 2/3 filled. The Sharps and BiohazardousWasteProcedure details proper disposal methods. • Non-disposable sharps are placed in a hard-walled container for transport and decontamination. • Do no handle broken glassware directly. Remove using a brush and dustpan, tongs, or forceps. • Use proper PPE. Blending, Grinding, Sonicating, Lyophilizing, and Freezing The greatest risk when using any of these devices is the creation of aerosols. • Blenders, grinders, sonicators, lyophilizers, etc. must be operated in a biosafety cabinet whenever possible. Shields or covers must be used whenever possible to minimize aerosols and splatters. • Safety blenders should be used. Safety blenders are designed to prevent leakage from the bottom of the blender jar and to withstand sterilization by autoclaving. They also provide a cooling jacket to avoid biological inactivation. • Avoiding glass blender jars prevents breakage. If a glass jar must be used, it must be covered with a polypropylene jar to contain the glass in case of breakage. • A towel moistened with disinfectant must be placed over the top of the blender while operating. This practice can be adapted to grinders and sonicators as well. • Aerosols must be allowed to settle for five minutes before opening the blender jar (or grinder or sonicator container). • Lyophilizer vacuum-pump exhaust must be filtered through HEPA filters or vented into a biosafety cabinet. • Polypropylene tubes should be used in place of glass ampoules for storing biohazardous material in liquid nitrogen. Ampoules can explode, causing eye injuries and exposure to the biohazardous material. • Use proper PPE. Open Flames When sterilizing inoculating loops in an open flame, aerosols that may contain viable microorganisms can be created. Open flames are also an obvious fire hazard.