They're usually just as safe as your household stove. You might argue that they are safer because an electric range needs twice the power (a 240V outlet), whereas countertop options require a 120V outlet. Their use is what can make them less safe. It's a bad idea to "expand" your stove and add a countertop cooktop burner, but place it next to the sink. You're putting your electrical components at risk. It's asking for an accident or a simple fire. These can also cause burns if placed on hot stoves in the kitchen. Avoid using these items on high breakfast bars or slim counters. Last, safety is important: If your countertop burner uses butane gas as its fuel, make sure you have enough ventilation. These burners are less safe during winter because people won't open their windows to let the cold in.