This double filtered balance system is a Class I biological safety cabinet that contains airborne particulates and powders, providing user protection during hazardous drug compounding or pharmaceutical manipulation. It is designed to meet the USP requirements for non-sterile hazardous compounding. This system exhausts air through two levels of HEPA filtration, returning it safely to the lab. Both filters are 100 % scannable, and can be replaced using a true bag-in/bag-out system. No outside ducting is required.