Is it okay to use this small animal bedding if it's been sitting out this long?

Probably about a month ago I bought everything I needed for a rat, but I decided I would wait to get him. I was so excited when I got the stuff, though, that I put it all together and set up his cage and everything. The bedding has just been sitting in there since, nothing else has been in the cage though. Do I need to throw that bedding out still? I would think so, because of dust particles, and I definitely don't want to harm my new ratty :] Also, I have sort of a..situation. My dad doesn't want me to get another animal but my mom doesn't care. I can have it as long as he's hidden and if my dad finds out, then she has nothing to do with it. She suggested I keep him in my closet? Is this even okay? The only time he'll actually be in the closet though, is real late at night until I wake up early in the morning, since my dad works during the day. And the weekends whenever he's around (which he barely is.) I have a light in my closet, ya know, so he won't get cold or anything. And it's not too cramped in there. )But I'm still not sure. If it will harm him, then I definitely won't do it. Just need a second opinion.