I have been carrying acid in the field for over 40 years in small screw top bottles like the one at:
http://minerox.com/index.cfm?fuseaction=product.display&product_ID=1372They can be found at any geology, mining, rock hound, etc. shop.
I have never lost a top (while carrying

) or had a leak. Most of the time I carry them in a belt case or in the pocket of a belt case, but I often carry them in a pocket or pack.
Respectfully,
Jerry