Propane gas is neither toxic nor injurious to you, should you be exposed to it in small quantities. However, should a leak occur, the accumulation of propane gas can become dangerous. Because propane is heavier than air, it tends to settle in the lowest available place. Very small amounts of propane are required to create a flammable mixture of gas and air. In the limited space of a recreation vehicle, for instance, very little propane is needed to create a hazardous situation.
Propane requires a large volume of air to burn properly.
In fact, 23.5 cubic feet of air is needed to burn just one cubic foot of propane. With adequate ventilation, an operating burner gives off a number of harmless products such as carbon dioxide and water vapour however, a propane appliance starved of oxygen can quickly produce dangerous amounts of carbon monoxide. For safety's sake, use your propane appliance only for the purpose for which it was designed. Don't, for example, use a stove as a space heater. Carbon monoxide is both colourless and odourless.