A UV dosimeter label made from films of polyvinyl alcohol and Swietenia mahagoni bark extract

In daily life, we are all exposed to ultraviolet (UV) radiation, which, in excessive doses, is very harmful to skin health. To measure UV intensity in everyday life, UV labels must be developed to determine the UV dose received in a simple and practical way. This paper reports on the development of a UV dosimeter label that is fabricated from polyvinyl alcohol (PVA) film and natural dye extract. The film labels were prepared by mixing extracts of Swietenia mahagoni and PVA with dye to 30% concentration. The film was characterized by using Fourier transform infrared spectrometry, UV-visible spectrometry, and colorimetry. The response of film labels to UV exposure was studied by exposing them to UV radiation at intensities of 0, 2, 3, 4, and 5 kJ/m². The effects of time and storage conditions on the color stability of the film labels were evaluated for seven days. After exposure to UV radiation, the film labels change color from brown before exposure to increasingly dark brown with increasing UV intensity. The results of this experiment show that film labels made of PVA and Swietenia mahagoni extract provide a sensitive measure of the intensity of UV radiation. (paper)