A detailed study was performed to develop the dosimetric characteristics of commercial low-density polyethylene film (LDPE), which is, by far, the most commonly used plastic for food and for many other-purpose packaging film, to be used as a film dosimeter for large-dose gamma-radiation dosimetry. The useful dose range extends up to 880 kGy. Correlations were established between the absorbed dose of gamma-radiation and the radiation-induced changes in LDPE measured using Fourier transform infrared (FTIR) and ultraviolet (UV) spectrophotometry. The results showed a significant dependence of the response on the selected readout tool of measurements whether FTIR (at 1716 cm(-1)) or UV (at 220 and 270 nm) as well as on the quantity used for calculation. The radiation-chemical yield of the ketonic carbonyl group produced in irradiated LDPE film was found to be 0.7 mu mol/J. The assessment of the random uncertainty associated with the measurement of the dose response and the effect of relative humidity during irradiation on the dosimeter performance as well as the postirradiation stability at different storage conditions are discussed.