National Toxicology Program

National Toxicology Program

Scientific Review of Phenolpthalein

CASRN 77-09-8
Status: Listed in the Report on Carcinogens (RoC)

Primary Uses or Exposures: Phenolphthalein in 1% alcoholic solution is used as a visual indicator in titrations of mineral and organic acids and most alkalies. It has also been used as an over-the-counter laxative.

Background Document

Public Comments


Note on Accessibility: Persons with disabilities or using assistive technology may find some documents are not fully accessible. For assistance, contact Central Data Management or call 919-541-3419 and identify the documents/pages for which access is required. We will assist you in accessing the content of these files. NIEHS has helpful information on accessibility.

NTP is located at the National Institute of Environmental Health Sciences, part of the National Institutes of Health.