Did you know that cashews raw in their shell contain urushiol, a toxin that causes a delayed allergic skin reaction similar to that caused by poison ivy. Roasting or steaming shelled cashews at high temperatures removes any urushiol that may have soaked through their shells and into the nuts, making them unsafe to consume.
This is why cashews are not sold in stores with their shells still intact, as well as why they’re typically sold roasted or otherwise heat-exposed. Even cashews labeled as raw in stores have been shelled and heat-treated, either through roasting or steaming, to remove urushiol residue. Raw, in this sense, indicates that they have had nothing else added to them, such as salt or flavoring.