The FDA is required to maintain a list of “Harmful and Potentially Harmful Constituents” (HPHC) in tobacco products. The original list was released in 2012 and was mostly toxicants in cigarette and other tobacco smoke and smokeless tobacco. In particular, this list did not include important compounds in e-cigarettes and other “new” tobacco products. In 2019, FDA proposed adding 19 compounds to the list that were in these products. Despite the fact that the proposal only attracted only 40 mostly supportive public comments (as opposed to nearly 200,000 on the proposed menthol ban), FDA did not finalize the updated list.
Until now.
On April 22, 2026, FDA announced that it had added 18 of the proposed new constituents to the HPHC list. FDA also proposed adding pulegone, furfuryl alcohol, and methyl eugenol that are often added to e-liquid formulations as flavoring ingredients and used in other tobacco products. (The FDA seems to be moving quickly on this proposal; public comments on these additions are due in just a month: May 26, 2026.)
FDA did not add the ethyl acetoacetate because it “does not meet any of the criteria for adding constituents to the HPHC list, including that NIOSH has not identified it as having adverse respiratory effects.” Public commenters should address this omission.
Nevertheless, the 18 added compounds are very important because, while not a formal product standard, the HPHC list provides a framework for assessing new products and reduced risk claims.
Significantly, the updated list includes propelyene glycol (PG) and vegetable glycerine (VG, listed as glycerol), the main solvents in e-liquids. As we detailed in our public comment supporting the FDA’s proposal to include PG and VG on the HPHC list, PG damages lungs and heating it up generates other toxins, including formaldehyde, acetaldehyde, and acrolein that are on the original HPHC list. In addition, PG/VG, while not carcinogens (tumor imitators) dramatically accelerate tumor growth and metastasis.
The question now is whether FDA will seriously use the updated HPHC list to reassess its permissive policy on e-cigarettes and heated tobacco products and other newer tobacco products based on the updated list and recognize that disease risk associated with e-cigarette use is nearly as high as smoking or continue its policy of assuming that they are much safer than cigarettes because they do not burn tobacco.
Stanton Glantz blog 