Harmful and Potentially Harmful Constituents (HPHCs)
The Food, Drug and Cosmetic Act (FD&C Act) requires tobacco manufacturers and importers to report the levels of harmful and potentially harmful constituents (HPHCs) found in their tobacco products and tobacco smoke and/or aerosol. HPHCs are chemicals or chemical compounds that cause or could cause harm to users or non-users of tobacco products.
FDA must publish HPHC quantities in each brand and subbrand of tobacco product, in a way that people find understandable and not misleading. FDA continues to research the best ways to communicate about:
- the dangers posed by chemicals and chemical compounds in tobacco products and smoke and/or aerosol and
- how to present HPHC levels in each brand and sub-brand of tobacco product so that they are clear and understandable.
In the meantime, FDA created three videos to lay the foundation for this important public health goal by exploring the chemicals in tobacco in three stages of cigarettes, from plant to product to puff. FDA also includes messages about HPHCs in its public health education.
HPHC List
FDA published a preliminary list of 93 HPHCs in March 2012, and updated the list with an additional 18 HPHCs in April 2026. The HPHC list focuses on chemicals that are linked to the five most serious health effects of tobacco use:
- Cancer
- Cardiovascular disease
- Respiratory effects
- Reproductive problems
- Addiction
FDA continues to review relevant science to determine whether to add additional constituents to the list.
FDA is currently requesting comments on three proposed additions to the HPHC list: pulegone, furfuryl alcohol, and methyl eugenol. These constituents are often added to e-liquid formulations as flavoring ingredients, but may also be present in other tobacco products, such as cigarettes and smokeless tobacco. Public comments must be submitted by 11:59 p.m. ET on May 26, 2026, to ensure they are considered by FDA.
List of the Chemicals and Chemical Compounds Identified by FDA as Harmful and Potentially Harmful Constituents in Tobacco Products and Tobacco Smoke and/or Aerosol
| Constituent | Reason for inclusion on HPHC list |
|---|---|
| Acetaldehyde | Carcinogen, Respiratory Toxicant, Addictive |
| Acetamide | Carcinogen |
| Acetic Acid | Respiratory Toxicant |
| Acetoin (also known as 3-hydroxy-2-butanone) | Respiratory Toxicant |
| Acetone | Respiratory Toxicant |
| Acetyl Propionyl (also known as 2,3-pentanedione) | Respiratory Toxicant |
| Acrolein | Respiratory Toxicant, Cardiovascular Toxicant |
| Acrylamide | Carcinogen |
| Acrylonitrile | Carcinogen, Respiratory Toxicant |
| Aflatoxin B1 | Carcinogen |
| 4-Aminobiphenyl | Carcinogen |
| 1-Aminonaphthalene | Carcinogen |
| 2-Aminonaphthalene | Carcinogen |
| Ammonia | Respiratory Toxicant |
| Anabasine | Addictive |
| o-Anisidine | Carcinogen |
| Arsenic | Carcinogen, Cardiovascular Toxicant, Reproductive or Developmental Toxicant |
| A-α-C (2-Amino-9H-pyrido[2,3-b]indole) | Carcinogen |
| Benz[a]anthracene | Carcinogen, Cardiovascular Toxicant |
| Benz[j]aceanthrylene | Carcinogen |
| Benzene | Carcinogen, Cardiovascular Toxicant, Reproductive or Developmental Toxicant |
| Benzo[b]fluoranthene | Carcinogen, Cardiovascular Toxicant |
| Benzo[k]fluoranthene | Carcinogen, Cardiovascular Toxicant |
| Benzo[b]furan | Carcinogen |
| Benzo[a]pyrene | Carcinogen |
| Benzo[c]phenanthrene | Carcinogen |
| Benzyl Acetate | Respiratory Toxicant |
| Beryllium | Carcinogen |
| 1,3-Butadiene | Carcinogen, Respiratory Toxicant, Reproductive or Developmental Toxicant |
| Butyraldehyde | Respiratory Toxicant |
| Cadmium | Carcinogen, Respiratory Toxicant, Reproductive or Developmental Toxicant |
| Caffeic acid | Carcinogen |
| Carbon monoxide | Reproductive or Developmental Toxicant |
| Catechol | Carcinogen |
| Chlorinated dioxins/furans | Carcinogen, Reproductive or Developmental Toxicant |
| Chromium | Carcinogen, Respiratory Toxicant, Reproductive or Developmental Toxicant |
| Chrysene | Carcinogen, Cardiovascular Toxicant |
| Cobalt | Carcinogen, Cardiovascular Toxicant |
| Coumarin | Banned in food |
| Cresols (o-, m-, and p-cresol) | Carcinogen, Respiratory Toxicant |
| Crotonaldehyde | Carcinogen |
| Cyclopenta[c,d]pyrene | Carcinogen |
| Diacetyl | Respiratory Toxicant |
| Dibenz[a,h]anthracene | Carcinogen |
| Dibenzo[a,e]pyrene | Carcinogen |
| Dibenzo[a,h]pyrene | Carcinogen |
| Dibenzo[a,i]pyrene | Carcinogen |
| Dibenzo[a,l]pyrene | Carcinogen |
| Diethylene Glycol | Poisonous Chemical |
| 2,6-Dimethylaniline | Carcinogen |
| Ethyl Acetate | Respiratory Toxicant |
| Ethyl carbamate (urethane) | Carcinogen, Reproductive or Developmental Toxicant |
| Ethylbenzene | Carcinogen |
| Ethylene Glycol | Respiratory Toxicant, Reproductive or Developmental Toxicant |
| Ethylene oxide | Carcinogen, Respiratory Toxicant, Reproductive or Developmental Toxicant |
| Formaldehyde | Carcinogen, Respiratory Toxicant |
| Furan | Carcinogen |
| Furfural | Respiratory Toxicant |
| Glu-P-1 (2-Amino-6-methyldipyrido[1,2-a:3',2'-d]imidazole) | Carcinogen |
| Glu-P-2 (2-Aminodipyrido[1,2-a:3',2'-d]imidazole) | Carcinogen |
| Glycerol | Respiratory Toxicant |
| Glycidol | Carcinogen |
| Hydrazine | Carcinogen, Respiratory Toxicant |
| Hydrogen cyanide | Respiratory Toxicant, Cardiovascular Toxicant |
| Indeno[1,2,3-cd]pyrene | Carcinogen |
| IQ (2-Amino-3-methylimidazo[4,5-f]quinoline) | Carcinogen |
| Isoamyl Acetate | Respiratory Toxicant |
| Isobutyl Acetate | Respiratory Toxicant |
| Isoprene | Carcinogen |
| Lead | Carcinogen, Cardiovascular Toxicant, Reproductive or Developmental Toxicant |
| MeA-α-C (2-Amino-3-methyl)-9H-pyrido[2,3-b]indole) | Carcinogen |
| Mercury | Carcinogen, Reproductive or Developmental Toxicant |
| Methyl Acetate | Respiratory Toxicant |
| Methyl ethyl ketone | Respiratory Toxicant |
| 5-Methylchrysene | Carcinogen |
| 4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) | Carcinogen |
| Naphthalene | Carcinogen, Respiratory Toxicant |
| n-Butanol | Respiratory Toxicant |
| Nickel | Carcinogen, Respiratory Toxicant |
| Nicotine | Reproductive or Developmental Toxicant, Addictive |
| Nitrobenzene | Carcinogen, Respiratory Toxicant, Reproductive or Developmental Toxicant |
| Nitromethane | Carcinogen |
| 2-Nitropropane | Carcinogen |
| N-Nitrosodiethanolamine (NDELA) | Carcinogen |
| N-Nitrosodiethylamine | Carcinogen |
| N-Nitrosodimethylamine (NDMA) | Carcinogen |
| N-Nitrosomethylethylamine | Carcinogen |
| N-Nitrosomorpholine (NMOR) | Carcinogen |
| N-Nitrosonornicotine (NNN) | Carcinogen |
| N-Nitrosopiperidine (NPIP) | Carcinogen |
| N-Nitrosopyrrolidine (NPYR) | Carcinogen |
| N-Nitrososarcosine (NSAR) | Carcinogen |
| Nornicotine | Addictive |
| Phenol | Respiratory Toxicant, Cardiovascular Toxicant |
| PhIP (2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine) | Carcinogen |
| Polonium-210 | Carcinogen |
| Propionic Acid | Respiratory Toxicant |
| Propionaldehyde | Respiratory Toxicant, Cardiovascular Toxicant |
| Propylene Glycol | Respiratory Toxicant |
| Propylene oxide | Carcinogen, Respiratory Toxicant |
| Quinoline | Carcinogen |
| Selenium | Respiratory Toxicant |
| Styrene | Carcinogen |
| o-Toluidine | Carcinogen |
| Toluene | Respiratory Toxicant, Reproductive or Developmental Toxicant |
| Trp-P-1 (3-Amino-1,4-dimethyl-5H-pyrido[4,3-b]indole) | Carcinogen |
| Trp-P-2 (1-Methyl-3-amino-5H-pyrido[4,3-b]indole) | Carcinogen |
| Uranium-235 | Carcinogen, Respiratory Toxicant |
| Uranium-238 | Carcinogen, Respiratory Toxicant |
| Vinyl acetate | Carcinogen, Respiratory Toxicant |
| Vinyl chloride | Carcinogen |