Best containers to make and store CDS in?

What are the best containers to store and make CDS in? I know metal can not be used and the lids can not have rubber. I made CDS in a ball latch jar with a silicone gasget and stored it in the fridge in te same jar for a few days and then transfered it to a ball mason jar with a plastic lid. It has lost potency in a couple weeks, according to test strips. Also, I could smell it when I opened my fridge, so I figuted I must be loosing the gas.