The silver standard BAC might be considered less affected by biases, at least in terms of those described above, as an estimate of the gold standard BAC. The accuracy of the breathalyzer has been shown to be quite good and, with accurate assessment of the time between injury and arrival (and excluding those drinking after the injury), an approximation of the BAC at the time of injury can be constructed. However, estimation of the rate of elimination of ethanol from the body using the Widmark zero-order kinetic model would typically assume that the patient was in the descending portion of their BAC curve in order to estimate BAC at time of injury. This may be a very poor estimate of that BAC if the BAC curve is still in ascension at the time of injury, in which case the BAC at time of injury may be even lower than that at the time of assessment. In addition, if the time from last drink until the BAC measure was long enough such that the BAC reading was to fall to 0,
