We can never be too certain of anything, but I believe that the carcinogenic claims are based on a faulty study from the 60s that was later largely disproven in

We can never be too certain of anything, but I believe that the carcinogenic claims are based on a faulty study from the 60s that was later largely disproven in the late 70s, but the FDA never changed their guidance. I don't have the drive to find the studies in question right now (sorry :( ), but I think it came down to the mice they tested having particular metabolizers that humans do not. That, and they gave them very high concentrated doses, because for some reason they were all about that method. I certainly don't ingest things that way :)