Espa?ol
PDFs by language
Our 24/7 cancer helpline provides information and answers for people dealing with cancer. We can connect you with trained cancer information specialists who will answer questions about a cancer diagnosis and provide guidance and a compassionate ear.
Chat live online
Select the Live Chat button at the bottom of the page
Call us at 1-800-227-2345
Available any time of day or night
Our highly trained specialists are available 24/7 via phone and on weekdays can assist through online chat. We connect patients, caregivers, and family members with essential services and resources at every step of their cancer journey. Ask us how you can get involved and support the fight against cancer. Some of the topics we can assist with include:
For medical questions, we encourage you to review our information with your doctor.
In general, the American Cancer Society does not determine if something causes cancer (that is, if it is a carcinogen). Instead, we rely on the determinations of other respected agencies, such as the International Agency for Research on Cancer (IARC, part of the World Health Organization) and the US National Toxicology Program (NTP).
The lists below are from IARC and NTP. More information on each of these known and probable human carcinogens can be found on their websites.
To learn more about these agencies and how they study and classify cancer causes, see Determining if Something Is a Carcinogen.
Learn more about the topics in this list in the IARC monographs at .
Learn more about the topics in this list in the NTP’s Report on Carcinogens at .
Learn more about the topics in this list in the IARC monographs at .
Learn more about the topics in this list in the NTP’s Report on Carcinogens at .
The American Cancer Society medical and editorial content team
Our team is made up of doctors and oncology certified nurses with deep knowledge of cancer care as well as editors and translators with extensive experience in medical writing.
Along with the American Cancer Society, other sources of information include:
International Agency for Research on Cancer (IARC)
Website:
IARC Carcinogen Monographs:
National Toxicology Program (NTP)
Website:
Report on Carcinogens:
Environmental Protection Agency (EPA)
Website:
Integrated Risk Information System:
Food and Drug Administration (FDA)
Website:
National Cancer Institute
Website:
Cancer Causes and Risk Factors:
National Institute for Occupational Safety and Health (NIOSH)
Website:
NIOSH Safety and Health Topic – Occupational Cancer:
NIOSH Carcinogen List:
*Inclusion on this list does not imply endorsement by the American Cancer Society.
No matter who you are, we can help. Contact us anytime, day or night, for information and support. Call us at 1-800-227-2345 or visit www.cancer.org.
International Agency for Research on Cancer (IARC). Agents Classified by the IARC Monographs, Volumes 1–132. 2022. Accessed at https://monographs.iarc.who.int/agents-classified-by-the-iarc/ on July 8, 2022.
International Agency for Research on Cancer (IARC). Preamble to the IARC Monographs. 2019. Accessed at https://monographs.iarc.fr/preamble-to-the-iarc-monographs/ on July 8, 2022.
US Department of Health and Human Services. Public Health Service, National Toxicology Program. 15th Report on Carcinogens. 2021. Accessed at https://ntp.niehs.nih.gov/whatwestudy/assessments/cancer/roc/index.html on July 8, 2022.
Last Revised: August 1, 2024
American Cancer Society medical information is copyrighted material. For reprint requests, please see our Content Usage Policy.
Sign up to stay up-to-date with news, valuable information, and ways to get involved with the American Cancer Society.
If this was helpful, donate to help fund patient support services, research, and cancer content updates.