National Toxicology Program

(CAS# 77-09-8)

• 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.
• Nominated by: NIEHS
• Basis for Nomination: NTP Bioassay (TR-465) that reported clear evidence of carcinogenicity in experimental animal groups
• Current Status: Listed in the RoC as reasonably anticipated to be a human carcinogen since the 9th RoC (2000)