UV-C sensitive composition and dosimeter

2The invention is a UV sensitive composition that undergoes a color change upon exposure to a predetermined dosage of UV-C radiation. The UV-C sensitive composition comprises a halogenated polymer, such as polyvinylidene chloride, that produces an acid upon exposure to UV radiation, and a pH sensitive dye. Upon exposure to UV-C radiation, the halogenated polymer undergoes degradation and produces HCl. The pH sensitive dye changes color as a result in an increase in HCl in the system. The composition may also include an acid scavenging composition and/or a diluent to control the amount of HCl produced in the system. The amount of HCl liberated from UV-C exposure may be selectively controlled so that a color change may be produced at a desired UV-C dosage. In some embodiments, the composition may be used to indicate a UV-C dosage from about 100 to 1600 mJ/cm.