A biological safety cabinet modified for bedding disposal was tested to determine the cabinet's ability to protect operators and experiments from aerosol exposure during routine microbiological and cage cleaning procedures. Stringent test conditions were provided by modifications of standardized protocols in addition to simulated cage dumping procedures, both of which utilized bacterial aerosols as challenges. Results of standardized test procedures (with no operator present) indicated good performance in protecting both operators and experiments. Procedures involving the dumping (by an operator) of contaminated bedding within the unit showed that the cabinet was able to contain 99.96% or greater of the total particles generated.