a dispenser for dispensing , liquid substances or substances in the form of cream or paste , comprising a pump in which in addition to the non - return valve , the elastic structure for returning the piston into its rest position following the operation of the dispensing knob are also of plastics material , and consist of a skirt which deforms elastically when the knob is pressed . to make the dispenser completely salvageable , all its constituent elements are of one and the same plastics material , which is of a type from which both substantially rigid pieces and substantially elastically deformable pieces can be formed . such a plastics material is for example polyethylene .