Many of the bagged shavings on the market today are made up of by-product. Saw mills generate waste when they process wood. Whether it is from circular saws,
planers, band saws, or sanders, this is considered to be by- product. It is basically waste and there is no guarantee as to what type of wood it is. It may be mostly pine, but contain other
species as well. Unfortunately this means hardwood or even treated wood may be mixed in with it. There are situations where chemicals that are used in the mills such as glue resins, stains, wood
fillers, paint, or sealants are present but you can't see it. It really is not worth the risk when using this for animals that you actually care about! Normally by-product is higher in moisture
content and contains a lot of dust. This is the reason that some bags weigh so much, but usually have a low expansion rate. Most companies that have by-product blame the lack of material on the
housing market and this is why. Their plants usually consist of a bagger and a big pile of by-product.
This is an example of typical by-product.