Preserve kitchen and tableware are dishwasher, microwave, and freezer safe. When using a dishwasher, we recommend a low-temperature setting in order to avoid exposing the products to the heating coil that heats up during the drying cycle. However, we have tested Preserve products in commercial washers that run at around 180 degrees, with no ill effects.  Most home washers run at around 120 degrees, so you should be able to run Preserve products through your dishwasher without any problems.
In regards to microwave use, Preserve's kitchen and tableware have been tested for microwave durability and will not break, crack, warp or get too hot when used to reheat food in the microwave to a comfortable eating temperature. The strength of microwaves varies, so please follow your manufacturer’s instructions to determine the appropriate times and power levels to reheat food in your microwave.  Preserve plastics can melt or warp when used to cook food in the microwave.
Preserve products are also freezer safe. However, please be aware that like all plastics, polypropylene can become brittle at very cold temperatures.  The container can crack or break if dropped or bumped hard when frozen.