Not everyone is going to carry a CPR mask on their belt or on their person 24/7, so a more feasible option is the small foldable face shield. It's sort of like a food baggie with a center section which allows for air to pass one way & does not allow for fluids to pass the other way. These are much more convenient to carry in a wallet, a pocket, a car's glove box, etc. Get one and always have it handy.