In most circumstances, you would be correct. But, we made provisions for insuring purity. We tried freezing them in the tunnel, and shipping them in refrigerated trailers. Also, we let some of them melt, after freezing, and shipped them by hermetically sealed tankers. They were unloaded through a 6" valve, which gave us perfect 6" cylinders. Very lttle sawing or machine work. That's how we got the 99% purity. With the EPA restrictions on groundwater contamination, you can't be too careful.

Thanks!!!

Wilco in Tennessee.