Just give the place a call like I did. You might be surprised as to what they will say. There is usually a 1800 # on the bags.
I just decided to call one day just to play it safe. Again not saying that they all are like this but this place told me they use the same equipment with cedar products they make and yes there can be some Pcs in the mix..

At least they were honest. As far as how many Parts per bag they think were in there they could not honestly say.
Just a wierd thing I found out and you can as well..