In a prior post, it was noted that OEHHA, the agency that oversees the administration of Proposition 65, had begun the highly controversial process of listing caffeine as a reproductive toxicant. As noted then, the listing (if it happens) will achieve a bizarre result. Because caffeine is a naturally occurring "food" substance, coffee will not have carry a Prop. 65 warning even though the level of caffeine in coffee is much higher than in soft drinks, tea, and chocolate. Caffeinated soft drinks, in contrast, will have to carry the warning because caffeine is added to soft drinks, even though the caffeine level in most soft drinks is much less than in coffee; like coffee, tea and chocolate will likely be exempt since their caffeine is also "naturally occurring". This type of labeling may result in substantial consumer confusion, to be kind. See http://www.oehha.ca.gov/prop65/public_meetings/pdf/MacInnis_Dart2.pdf.
The ultimate absurdity of this dichotomy is also shown by a prior post which noted that a recent study showed that caffeine was linked quantitatively to miscarriages no matter what the source (coffee, caffeinated soda, tea, or hot chocolate). The two doctors on OEHHA's advisory committee both voted "no" re further action (the final vote was 4-3 in favor of moving forward) because apparently the medical community does not consider low caffeine intake to be a meaningful risk.
Be that as it may, OEHHA has decided to move forward. It will prepare what are called Hazard Identification Documents describing the strength of the scientific information supporting the possible listing. Interested parties should submit comments and data by August 26. See http://www.oehha.ca.gov/prop65/CRNR_notices/state_listing/data_callin/crnr062708.html. A September, 2007 OEHHA summary of the data about caffeine and its adverse effects can be found at http://www.oehha.ca.gov/prop65/CRNR_notices/state_listing/pdf/dart090707_5.pdf.