One of the nerdy, but very important, parts of the FDA tobacco product regulatory process is the list of “Hazardous and Potentially Hazardous Compounds” (HPHC) list that FDA released in 2012. This list contains 93 bad chemicals — mostly carcinogens — that FDA identified as important when assessing the risks of tobacco products.
It has become the de facto standard for whether new products might be less risky.
While everything on the list belongs there, it is badly out of date because it is based on cigarettes and e-cigarettes and other new products are not just cigarettes less bad stuff, they are different in ways that expose users to different risks.
In addition, there is already strong evidence that e-cigarettes increase the risk of cardiovascular and pulmonary disease, and many toxins that cause these diseases are not on the current HPHC list.
FDA proposed updating the HPHC list in 2019 by adding 19 compounds to the list that goes beyond carcinogens and reflects important toxins in new products, such as propylene glycol. As summarized in a public comment my UCSF colleagues and I submitted at the time, these additions were well-justified. (We also suggested some additions.)
Unfortunately, FDA never finished the process and released the new list.
In the last three years, the existing list has become more out-of-date.
Fortunately, unlike many proposed FDA rules that attracts hundreds of thousands of public comments (thanks to industry PR efforts), the proposed new list only attracted 40 public comments (including ours). Reviewing these comments and releasing a finalized new list should not be that hard for FDA.
But, because of the central role that the HPHC list plays in development of regulations and review of PMTA applications for authorization of new products, FDA needs to finish the job and release the updated list so that everyone — including industry — can start using it.