Abstract: A microbial decontamination unit (A) has a door (B) which is hingedly mounted (90) to the housing. When the door is opened, the operator has access to a decontamination chamber (22), a mixing chamber (10) for receiving an anti-microbial solution concentrate, and other anti-microbial solution circulation paths (18). A mechanical locking mechanism (D) selectively locks the door member against a gasket (92) to assure that the anti-microbial solution does not leak between the door and the housing. The latch mechanism includes a hook member (54) that defines a circular bearing surface (52) that is rotatably received on a circular cam member (50). The circular cam member (50) is eccentrically mounted on a shaft (40). Rotation of the shaft and cam member moves a latch engaging surface (56) of the hook member into and out of engagement with a latch member (58) along an axis of travel (76).