Abstract: An enclosure provided with an air supply system, an exhaust system, and controls for manipulating the flow, temperature, dewpoint and relative humidity of the air within the enclosure are disclosed. The present invention aims to achieve with these components a system for containing chemical contaminants created during processing of silicon wafers during the chemical/mechanical, polishing/planarization processes involved in creating those wafers. The system prevents drying of the slurry used to process wafers by controlling the relative humidity within the enclosure via a humidifier, sensors and a controller that dynamically reacts to changes within the enclosure atmosphere. Preventing slurry drying is critical to maintaining high wafer throughput by reducing gouging and scraping of wafers and also by reducing equipment down time needed to clean dried slurry.