What's the shelf life of these? It's filtered water but depending on your supplier it might not be good for that long.

What is everybody going on about micro plastics here? Plastic is mostly inert and unless there is softeners leaking into the water, even if there were some micro plastics floating in the water, in which way would that be worse than sand dust? The body has to deal with micro particles since forever and these particles are supposed to be about as inert as sand. 

 You'll find that many people on the internet don't know what they are talking about.