They kind of already do that. Not sawdust but just take a look at the list of ingredients in most of the food you buy. A lot of those ingredients are banned in most countries and pose health hazards for consumers, yet we still use them. We need not only tougher regulations, but to also properly fund the FDA so they can inspect properly. Of course companies lobby heavily against that, and with our current administration, there is a bigger chance they kill of the FDA than that happening.