This comment may or may not be applicable, but the butane sold by EADS was crap when I lived in Boulder. Ditto Walmart. I only used it in lighters, and only once. It's so gunky that it clogs small lines. I had a hell of a time getting it out of my lighters. The cleanest butane is a brand called Colibri but it's very expensive. Vector is a more affordable brand that also works well. I smoked a tobacco pipe for many years, so I think I've tried every brand of butane.

Incidentally, a nice pipe lighter is good accessory for pot smokers. The built-in tamper and horizontal flame make smoking a mite more pleasant.