There are different types of Halon. The types of halon are what determines how toxic each one is however if memory serves me correctly none of them are designed for humans to be breathing. . Halon was designed to be used in confined spaces, such as computer rooms, and IT rooms, and was intended for electronic equipment fires as the agent does not ruin the equipment if it is needed. I am not sure how well it will work outside. If there is any kind of wind the agent will disperse quickly and be useless. Halon has been replaced by agents that do the same thing as halon, but do not effect the ozone. I am not sure if you can get halon refilled in all states and I am certain that the cost would be huge if you can. Just be careful with it if it is needed. Good Luck, Dave