Is the Big Buddy propane heater by Mr. Heater truly a safe indoor heater?

dont know the brand per se,,but is it vented or unvented?..if unvented [no vent pipe to carry exaust gases outside]..then its important that the area to be heated is large enough that the air in the room wont be used up so quickly that the exhaust gases aculate to an unsafe level or even cause carbon monoxide to aculate....the instructions probably contain the safe operating parameters......also important to have a carbon monoxide detecter in the same room [ opposite side] as the heater just in case something isnt right...preferabley the type that has a display of how much monoxide is in the air,,otherwise you wont know its aculating until its approaching a harmful level......i'm uming your local codes allow for your type heater to be used in the type of home you are in,,,might be good to get a combination "carbon monoxide" and "combustable gas" detecter since propane is heavier than air and will aculate from the floor up if there is a leak.....dan