All Double Walled Stainless, no matter the manufacturer, are not dishwasher safe. You must clean them by hand, and this includes taking the rubber seal/ring off of the lid and cleaning as well. If you don't clean the lid occasionally mold will grow on the seal and this could make you possibly ill. Again that does matter if it is a Polar Camel, or SubliCool from us or any other name brand. All double walled thermal tumblers/drinkware are made the same way and many are made in the same manufacturing facilities as the other brands.