Molson/Coors or whatever they call themselves now, seems to pride themselves lately when it comes to their environmental responsibility.

I imagine if you called their 1-800 number, hopefully you could find out if the ink they use is toxic or not.

I personally wouldn't use it until I knew for sure. Not worth the risk. You may have access to plain cardboard elsewhere, without a lot of effort.

Please post on here if you get an answer from Coors.

If you do call them, ask also about other chemicals that may not be so great. I know that most 'beverage boxes' are also made with a sizing additive that keeps a broken can, condensation, etc. from making the box disolve. I don't think sizing is something you want in your soil.