Looking up, my guess is you are using HEET product that removes water from gasoline (aka "dry gas") that used to be methanol but I think now is isopropyl alcohol? DON'T use a typical HDPE Nalgene bottle; HDPE is supposed to be safe with isopropyl alcohol, but turned mine brittle, dropped on floor and cracks everywhere (very abnormal for HDPE) holding 90% iso for 6 months in my first aid kit. After emptying I squeezed bottle, entire bottle turned to spiderweb of cracks. Very weird because bottle that alcohol comes in from store, says HDPE on bottom, same as Nalgene bottle.