Abstract: A self-cleaning asbestos collection system comprises a covered hopper, and enclosed housing, and a slide gate valve. The slide valve has a valve gate that is operable between a latched position in sealing contact with the hopper mouth and an unlatched position. An over center lock in the latching mechanism assures positive latching. A second mechanism is operable when the valve gate is unlatched to reciprocate the valve gate between positions wherein it covers and uncovers the housing mouth. The housing has a spout under the hopper mouth. As asbestos bag is installed over the spout for receiving material flowing through the hopper mouth and the slide gate valve without contaminating the atmosphere. Water nozzles installed inside the housing make the asbestos collection system self-cleaning.