I have seen that Harbor Freight sell a llttle adapter for refilling the small disposable bottles from a larger 20 or 30 pound bottle.
It would be quite a $ saving (although they charge $20 for the little adapter!) and I have been tempted, but have resisted so far because of what I have read about it not being legal to transport them - though how anyone would ever know is beyond me!
Im not really sure what the hazard would be - other than maybe it is possible to overfill a bottle?
Brian & Connie Mitchell
2005 Classic 30'
Hensley Arrow / Centramatics
2008 GMC Sierra SLT 2500HD,4x4,Crew Cab, Diesel, Leer cap.