Is a Slow Cooker Safe?
Yes, the slow cooker, a countertop electrical appliance, cooks foods slowly at a low temperature—generally between 170° and 280° F. The low heat helps less expensive, leaner cuts of meat become tender and shrink less.
The direct heat from the pot, lengthy cooking and steam created within the tightly-covered container combine to destroy bacteria and make the slow cooker a safe process for cooking foods.
Source: Food Safety and Inspection Service (FSIS)