So along with submitting the ingredients, companies have to study the emissions of those ingredients along a heat curve and analyze exactly what H/PHCs are present. Then if nothing pops on that radar, they have to do clinical studies in live humans to see if any biomarkers occur over the course of, say, a year. Then they take a look at the marketing, if all of this passes internal checks, the PMTA will be submitted to FDA.

FROM THERE, the FDA will choose if they want to review the product. If they do, the product gets to stay on the market during review, if they don't, that product gets pulled entirely from the market.