Grifols' Misterium is a modular concept cleanroom designed for mixing sterile preparations and preparing other compounds that require cleanroom conditions. The air is treated and pressure controlled using a HEPA filter to allow for the preparation of cytostatics and biohazardous products. The rooms comply with USP Chapter <797> for sterile compounding. Each modular cleanroom is configured and installed according to the pharmacy's specifications, and units can be installed in an existing facility without disrupting day-to-day activities.