If you have ever owned or used any kitchenware, you have likely seen logos somewhere on the kitchenware item that designates it as 'dishwasher safe,' 'oven safe,' 'microwave safe' or the like. Understanding the meaning of these designations is key to extending the longevity of your kitchenware items.
Dishwashers and Kitchenware
Using a dishwasher is a common way of making washing dishes easier and more convenient. Dishwashers vary depending on make and model, but many use a heating element to warm water and soak dishes; they then use a garden sprinkler-like device to rinse off the dishes. Using a dishwasher can therefore save you lots of effort in washing dishes by hand. Because of their use of pressurised, heated water and agitation, however, dishwashers can damage some specific kinds of dishes and other kitchenware.
When a piece of kitchenware is stamped with a 'dishwasher safe' logo, it means, quite plainly, that it is safe to wash the item in a dishwasher. To put it another way, the logo means that the materials used to build the piece of kitchenware are unlikely to be damaged, scarred, or otherwise marred by the heat, pressure and agitation of being washed in a dishwasher.
As noted, the materials used in some kitchenware items are more likely to be damaged by a dishwasher. Plastic utensils and other items that have not been treated to handle intense heat could potentially melt in the high temperatures used by a dishwasher. Travel mugs are sometimes made with an internal or external metal layer that can easily be damaged by the intense agitation used in a dishwasher. Travel mugs are also commonly built with a pocket of air between the internal and external layers that aids in keep beverages warm; if water seeps into this air pocket, it can give the mug an unpleasant mildewy smell until the water eventually evaporates. Ceramic materials can also be easily damaged in a dishwasher due to their fragility when exposed to high temperatures.
For the most part, if a piece of kitchenware is stamped with a 'dishwasher safe' logo, you can generally assume you can wash it numerous times in the dishwasher with no ill effects. A dishwasher-safe item, however, still could be damaged in a dishwasher under certain conditions. If a kitchen item is not labelled with an indication of whether it is dishwasher safe or not, assume that it is not rather than risk damaging it by washing it in a dishwasher.