Under US law almost everything that was in common use before a certain date is “grandfathered in” and exempt from certain regulations.
The term to search for more information is GRAS, “Generally Recognized As Safe”.
It is extraordinarily difficult to get a GRAS substance regulated; for example aspirin would not be approved today.
Alcohol is even more special because it is not regulated as either a food or a drug, and because unlike artificial sweeteners, there are no ready substitutes. (Multiple artificial sweeteners have come and gone from the marketplace due to safety concerns.)
It’s also worth noting that it’s possible to over react to potential carcinogens. Here in California so many businesses have signs on their doors warning of potential carcinogen exposure that the signs are just ignored. (Yeah, I could avoid going to the supermarket because there’s a potential mild carcinogen in the cleaning solution they use on their floors. But almost nobody is going to care )
Latest Answers