The California Office of Environmental Health Hazard Assessment (OEHHA) added Aloe vera, non-decolorized whole leaf extract and Goldenseal root powder to the list of chemicals known to the State to cause cancer under Proposition 65, effective December 4, 2015. Proposition 65, also known as the Safe Drinking Water and Toxic Enforcement Act of 1986, requires the governor of California to publish a list of chemicals "known to the State to cause cancer or reproductive toxicity." The law mandates, in part, that no person may knowingly expose any individual to a significant amount of a listed chemical without first providing a "clear and reasonable warning" to such individual.

The basis for the listing of Aloe vera, non-decolorized whole leaf extract and Goldenseal root powder, according to OEHHA, is their classification in Group 2B (possibly carcinogenic to humans) by the World Health Organization’s International Agency for Research on Cancer (IARC). (See “Agents classified by the IARC Monographs, Volumes 1-112" (IARC, 2015)).

Whole leaf extract of Aloe vera is the liquid portion of the Aloe vera leaf, and is a natural constituent of the Aloe barbadensis Miller plant. It is not the same as Aloe vera decolorized whole leaf extract, Aloe vera gel, Aloe vera gel extract, or Aloe vera latex, which are not included in the listing. Goldenseal root powder is the powdered dried roots and underground stems of goldenseal plants.