This all depends upon the coolant or oil that is being used in the machine during the cutting process. If a shop is using oil, most companies will segregate chips by the material type, i.e., stainless with stainless. Some places will spin their chips to get all the oil off of them before they recycle. If plastic is being machined, then often the plastic can be melted down again. Segregating chips by type and oils/coolants is a process. In order to recycle properly, these shops must have the room to keep chips separated. Water soluble chips cannot be mixed with oily chips. If you are running 12L14 steel and the next job is stainless, in order to properly recycle the chips, an operator would have to clean out the machine, remove the chip bucket or drum containing the steel chips and put a new one under the chip conveyor for the stainless chips that are being made on the next job. All these factors have to be considered when a company implements a proper and responsible recycling program.