Organic Vapor/Acid Gas Cart. (6003). The 6000 Series Respirator is a NIOSH/MSHA approved half-mask respirator that is adaptable to a wide range of respiratory protection. Its low maintenance, comfortable design allows greater worker flexibility by the use of five different type cartridges and two types of pre-filters for a variety of work environments. Cartridges are simply twisted on or off of the facepiece for easy replacement which allows the facepiece to be used over and over. Supplied with a storage bag.