On April 23, 2015, California's Office of Environmental Health Hazard Assessment (OEHHA) announced its intent to list Aloe vera whole leaf extract and goldenseal root powder as carcinogens on its list of Chemicals Known to the State to Cause Cancer or Reproductive Toxicity (Proposition 65 list), pursuant to the Safe Drinking Water and Toxic Enforcement Act of 1986 (commonly known as Proposition 65). Once the chemicals are listed, a product that will expose individuals to either of these chemicals must bear a warning that the product contains a chemical known to the state of California to cause cancer.
Basis for Listing
OEHHA cites a mechanism called the "Labor Code Mechanism" as its basis for listing these two ingredients. As a matter of background, Proposition 65 contains a provision requiring that the Proposition 65 list of chemicals includes all substances identified in Labor Code Section 6382(b)(1). This section of the Labor Code identifies substances listed as human or animal carcinogens by the International Agency for Research on Cancer (IARC) as presumptive hazards. Therefore, under Proposition 65, all substances identified by the IARC as human or animal carcinogens must be added to the Proposition 65 list.
In 2013, IARC published conclusions after its review of relevant studies relating to the carcinogenicity of Aloe vera whole leaf extract and goldenseal root powder in Volume 108 of the IARC Monographs.1 IARC classified both ingredients as Group 2B chemicals ("possibly carcinogenic to humans"), based on its findings that there was "sufficient evidence of carcinogenicity in experimental animals." Notably, the only studies cited in the IARC Monograph regarding Aloe vera whole leaf extract involved oral administration of Aloe vera whole leaf extract to rats via drinking water.2
Scope of the Notice
The Notice of Intent to List (the notice), lays out specific limitations as to the species and the parts of the plant that OEHHA intends to list.
For Aloe vera, OEHHA stresses that this notice does not apply generally to all aloe varieties but applies only to the Aloe vera species, which is also known by the Latin name Aloe barbadensis Miller and the common names Barbados aloe, Mediterranean aloe, True aloe, and Curaçao aloe. In addition, this notice does not apply to all parts or products derived from the Aloe vera plant; rather, this notice applies only to the whole leaf extract, which is sometimes commonly referred to as whole leaf juice or just aloe juice. The notice specifically states that "Aloe vera whole leaf extract is not the same as Aloe vera decolorized whole leaf extract, Aloe vera gel, Aloe vera gel extract, or Aloe vera latex," which would not be covered by the listing of Aloe vera whole leaf extract.
With regard to goldenseal root powder, the notice specifies that this listing applies to the species Hydrastis canadensis, which is also known by the common names orangeroot, Indian turmeric, and curcuma. The notice specifies that "goldenseal root powder is the powdered dried roots and underground stems of goldenseal plants. Goldenseal root powder is a natural constituent of the goldenseal plant." OEHHA also clarifies that this listing does not apply to turmeric (Curcuma longa).
Opportunity to Comment
OEHHA is providing an opportunity for public comment on these listings. However, OEHHA has severely limited the scope of comments that will be considered by the agency. Because the ingredients are being listed pursuant to the Labor Code Mechanism, which automatically requires the listing of all ingredients identified as carcinogens by IARC, OEHHA states in the notice that comments must be limited to whether IARC has identified the specific chemical as a known or potential human or animal carcinogen. The agency states that it "cannot consider arguments concerning the weight or quality of the evidence considered by IARC" when classifying the chemicals.
Comments must be received by OEHHA by 5:00 p.m. on Tuesday, May 26, 2015. Comments can be submitted in either electronic or paper format. We note that with past chemicals listed via the Labor Code mechanism, the time period between the notice of intent to list and the actual listing on the Proposition 65 list has been relatively short.
 Gross, Y. et al., Carcinogenicity of some drugs and herbal products, 14 THE LANCENT ONCOLOGY 807 (2013).
 Id. at 808.