Is it greener to refinish old flooring that has been chemically treated, or to replace it with green flooring?

Older flooring probably has most of the lacquers or waxes already gone. While some might have oil based stains, these have probably evaporated over time. While I would not burn them in my fireplace because what was left will pollute and you are not doing any good, I think dust from incomplete cleaning over the years is the greatest risk to human health.

I would not rush out to replace the old product with the new, because there is no net gain. When I decided to replace, I would employ great care however in the old floor’s disposal.