Alcohol Concentration of Breath. The alcohol concentration of breath shall be reported as grams of alcohol per 210 liters of breath (gram/210 liters). Alcohol Concentration of Blood. The alcohol concentration of blood shall be reported as grams of alcohol per 100 milliliters of blood (gram/100 milliliters). Uncertainty. For breath tests for alcohol content, the accepted scientific uncertainty in measurement is plus or minus 0.005 gram/210 liters or 10 percent of the average of measurements, whichever is greater. For blood tests for alcohol content, the accepted scientific uncertainty in measurement is plus or minus 0.005 gram/100 milliliters or 10 percent of the average of measurements, whichever is greater.