Inhaling propane gas has different symptoms depending on how much of the gas is inhaled. Respiratory protection is not needed while working with limited amounts of propane gas.
Propane gas does not have an effect on breathing by itself, but displaces oxygen from the air making it hard to breathe. If enough oxygen is displaced, a person could asphyxiate.
If the exposure to propane gas is minimal, there are little to no symptoms if inhaled. If oxygen is displaced from the air because of high quantities of propane gas, symptoms that are present are rapid heart rate, clumsiness and fatigue. The longer the exposure occurs, the less oxygen will be present, and symptoms such as vomiting, convulsions and even death can occur.