Development of a radiation-sensitive indicator

A poly(vinyl alcohol) (PVA) film containing acid-sensitive dye (bromophenol red, BPR) and water soluble chlorine-containing substance [CCl3COONa or chloral hydrate (CCl3CH(OH)(2), 2,2,2-trichloroethan-1,1-diol)] may be useful as a radiation-sensitive indicator. The acid-sensitive dye in the film changes its color from violet to pale yellow by irradiation due to the consequent lowering of the pH of the film caused by the HCl generated from the radiolysis of the Cl-containing substance. This film can be used as a dosimeter in a relatively low dose range up to 5 kGy. This response range makes this film useful in some food irradiation, pasteurization and water purification applications. The effects of temperature and relative humidity during irradiation and post-irradiation storage on the response of the film are discussed. It is inexpensive, does not require toxic solvents in preparation and easy to prepare in a laboratory. Copyright (C) 1996 Elsevier Science Ltd