1.1 ,The three test methods described herein are for measurement of water vapor transmission rates (WVTRs) of high-barrier multiple-unit containers (bottles), high-barrier single-unit containers (blisters), and quasi-barrier single-unit containers used for packaging pharmaceutical products. The containers are tested closed and sealed. These test methods can be used for all consumer-sized primary containers and bulk primary containers of a size limited only by the dimensions of the equipment and the weighing capacity and sensitivity of the balance.