Air conditioning refrigerant hazard
This practice is becoming more common in the United States. There have been numerous cases reported of teens and even adults being hospitalized due to huffing freon, as well as many deaths. (Try googling freon huffing)
When deeply inhaled, freon can cut off vital oxygen supply to ones cells and lungs. Purposely inhaling these fumes to get high can be extremely dangerous, possibly even fatal the very first time one tries it. Abuse of freon inhalation can lead to organ damage.
Freon can be easily removed from a homes outdoor AC unit (I wont say how here for fear of giving someone with the wrong intentions the knowledge). But this growing trend among teenagers in particular is alarming. Generally they will remove the freon gas into a plastic bag, and then huff the gas out of the bag to achieve a high.
If your homes air conditioning system is frequently running low on freon yet there is no evidence of a system leak, it could be that someone is purposely removing the refrigerant from your system in order to huff it.
Symptoms of mild to moderate freon poisoning include irritation of the eyes, ears and throat, headache, nausea, vomiting, frostbite (when used in liquid form), coughing, chemical burns to the skin, and dizziness. If you suspect someone is suffering from freon poisoning, call 911 immediately.
So what can homeowners do? For about $30-40 locking caps can be installed on the refrigerant services ports, requiring a special key to unlock. Although not 100% fool proof, these locking caps will help create a deterrent and make it much more difficult for anyone to purposely remove the freon from the system.
When used properly and as intended, refrigerants are completely safe. A refrigerant leak in a well ventilated area generally will cause no harm. But when misused intentionally, it can be lethal.