FIELD: chemical industry, more particularly use of nitroxyl inhibitors in combination with oxygen to prevent premature polymerization of aromatic vinyl monomers. SUBSTANCE: present invention describes composition which prevents premature polymerization of vinyl aromatic compound during its distillation or purification, said composition comprises vinyl aromatic compound and effective inhibiting amount of stable hindered nitroxyl compound. In order to increase inhibiting activity of compositions, claimed composition comprises nitroxyl compound in combination with effective amount or oxygen of air. Present invention also describes method of inhibiting premature vinyl aromatic compound during its distillation of purification in the presence of stable hindered nitroxyl compound in effective amount. In order to increase inhibiting activity, nitroxyl compound is used in combination with effective amount of oxygen or air. EFFECT: highly efficient use of nitroxyl inhibitors. 16 cl, 16 ex, 3 tbl
