In an electrical switching device which includes insulating parts subjected to the influence of electric arcs, the insulating parts are formed of mouldings having a binder which consists essentially of a mixture of a linear acrylate polymer and a monomeric acrylate compound which is polyethylene glycol dimethacrylate or a polyethylene glycol diacrylate converted into polymerized form. The binder may contain an additive resin containing ethylenically unsaturated groups in the monomeric acrylate compound in a quantity of at most 25 percent of the total weight of linear acrylate polymer, monomeric acrylate and additive resin. The binder may also contain a powdered filler or a fibrous reinforcing material.