The effect of UV radiation on the spectral properties of aqueous solutions of 2,6-di(hydroxymethyl)-4-methylphenol has been studied. Excilamps based on working molecules: KrCl (222 nm), XeBr (283 nm), and XeCl (308 nm) were used as UV radiation sources. The degree of photodegradation depends on the irradiation time, concentration of the examined compound, and characteristics of the excilamp used for irradiation.