There are still helium tanks in some stores which are pure helium.
Do not buy for self-deliverance (only balloon inflation) tanks which are marked HELIUM/AIR.
For instance, a supporter tells me that there are approximately 15 tanks of 100% helium at the below location, for those in need in the Philadelphia and suburban areas:
PARTY FAIR 169 Park Avenue, Willow Grove, PA 19090
Located in the shopping center directly off of Park Avenue, next to Kay Jewelers and Orange Theory Fitness stores.
Are full face CPAP masks effective and would they provide a better success rate for the 80/20 tank or is the helium amount too weak?
Face masks of all sorts are not recommended. They either blow off, or don’t fit properly — we all have differently shaped faces. Plus, the pressure of incoming gas may re-shape the face. In surgery, a doctor holds the face mask firmly down by hand. A plastic bag, tied at the neck, is the only way of successful, chosen self-deliverance to avoid further terminal suffering.