The air we breathe is comprised of less than 1% argon. Basically, for 1 trailer of argon we produce, we produce 20 trailers of oxygen. In a perfect world, we could sell our products in the same proportion that we make it. Unfortunately, it is quite common for argon demand to outpace oxygen and nitrogen, causing us to vent the excess product back in to the atmosphere. We list this as a separate charge as it fluctuates depending on the demand.