I always wash my fabrics when they come into the house. I drop them off on the washer until I can get them done.
I have two reasons for this.
1. The sizing put on them at the factory makes my eyes water. If I'm working on a quilt for a long time, it really gets to me.
2. The best reason of all....I was in a local quilt shop and saw a customer pick her nose and wipe it on a bolt of fabric. Never, ever, leave home without hand-sanitizer and don't forget to use it!!