Total fluorescence of aqueous phenylacetic acid system at neutral pH has been evaluated as low-dose -ray chemical dosimeter, using the fluorescence accessory of a UV-Vis spectrophotometer. The useful working range of the system is from 4 to 70 Gy. The postirradiation stability of the dosimeter response has been studied at different pH's, storage temperatures and light conditions. The post-irradiation stability of the dosimeter decreases with an increase in storage temperature. The stability is not affected in diffuse sunlight but it is very unstable in direct sunlight.