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.

We literally had to outlaw slavery. That should tell you everything you need to know about supposed self-regulation.

Elon Musk's original pitch for the underground hyperloop system / boring company included the claim that the dug out dirt would be repurposed as super building bricks, and that this would keep the projects at or under budget.

https://finance.yahoo.com/news/almost-7-years-ago-elon-145526694.html?guccounter=1

He literally did this, sold reformed, shitty dirt and called it a miraculous building material.