I was wondering, does anyone know what kind of wood shavings Premium Pak (out of California, i believe) is?

I seen a huge white bag of it at the feed store, yet it just states that it is "premium wood shavings." The person working there that day had no clue what kind it was, just that they use it for their small rodents.

During fall and winter, I always give my snakes aspen shavings to warm up in. Yes, they have other heat sources, too, so they definitely are not freezing, but they really like curling up under their substrate during winter. Especially my corn snake. During summer, they don't seem to like going in their bedding much at all, so I just use newspaper.

I was thinking of buying the big bag of Premium Pak, since it would last me quite awhile and I could store it in the freezer so nothing gets into it. But, I can't find any information on it!! I don't want to harm my snakes in any way. The person at the store let me sniff it, and it doesn't even really have any smell at all. I got to touch it, and it felt almost like light shreds of paper, but of course it looks like wood shavings. It felt really comfortable. I just don't know if it's safe, so I told them I'd have to pass until I found out what type of wood it was.

Any help would be greatly appreciated!