Infectious hazards of the high speed blendor and their elimination by a new design.

The high speed blendor or mixer has become an indispensible instrument in many biological laboratories. Since it was originally designed as a household appliance, no attention was given to the normally harmless aerosol which is created during its operation, nor was any minor leakage from the bearing considered to be important. However, when the blendor is used to cut up highly infectious tissue, the aerosol, and leakage from around the rapidly rotating drive shaft, become very dangerous to the operator. This has been so obvious that various precautionary practices have been initiated by different laboratories (Shepard, May, and Topping, 1945; Smadel, 1951; Sulkin and Pike, 1951). Preliminary to designing a leakproof mixing bowl, an investigation was carried out to determine the cause and extent of the escaping aerosol.