Abstract: A funnel-like tapered containment vessel of flexible sheet material has its smaller end portion normally closed by a valve and its other end portion open to define a mouth. Such vessel has a large flat lip that can be positioned under the source of a leak of hazardous liquid such that the liquid falls on the lip and is conveyed into the vessel. The open end portion of the vessel has an inflatable cuff including a top arcuate part which, when inflated, holds the upper portion of the mouth of the vessel open. The cuff includes a separate bottom part extending around the margin of the lip and inflatable to form a raised rim to prevent runoff. The normally closed valved end portion of the vessel can be connected to a collapsible collection container such as by a hose having quick-connecting end fittings.