A water- and solvent-free release agent for use in the production of articles of polyurethane foam contains one or more polyenes as the main constituent and also in addition if required a consistency adjuster, an antioxidant, accelerators and/or stabilizers. To apply water- and solvent-free release agents to the surfaces of polyurethane-foam moulding dies the misting or atomization of the release agent is effected with a device with an electrostatic charge, by which the release agent particles are given an electrostatic charge when passing through the exit nozzle.