Prop 65 Statement
In 1986, California voted to enact Proposition 65 (commonly referred to as Prop 65), a law that requires businesses to disclose warnings to Californians about significant exposures to chemicals that can cause birth defects, cancer, or harm to the reproductive system. The act’s official name is the “Safe Drinking Water and Toxic Enforcement Act of 1986.” The chemicals listed in Prop 65 can be either synthetic and released into the environment as a byproduct of various industries, or naturally occurring in the Earth’s crust and water supplies. The intention of Prop 65 is to enable Californians to make informed decisions about their exposures to chemicals. Examples of chemicals listed in Prop 65 include the heavy metals lead, cadmium, and arsenic, and acrylamide (a byproduct of frying, roasting, or grilling meats and plant foods). For reference, numerous commonly-consumed foods, including vegetables, fruits, rice, nuts, and seeds naturally contain lead, cadmium, and arsenic. Rice, in fact, is extraordinarily high in arsenic, a problem that has been brought to the attention of the medical community. (1)
There are two statutes in Prop 65: The first prohibits businesses from knowingly dispensing listed chemicals into drinking water sources or onto land where the chemicals can leach into drinking water sources. The second statute prohibits companies from knowingly exposing consumers to listed chemicals without providing a clear warning. The latter statute has significant implications for the supplement industry, as we will see shortly.
Prop 65 requires California to publish a comprehensive list of chemicals known to cause birth defects, cancer, or reproductive harm. This list is updated once a year, on average. Since it was first published in 1987, the index has grown to include upwards of 900 chemicals. Prop 65 strictly regulates chemicals that have demonstrated a 1/100,000 chance of causing cancer over 70 years or that are present at a level 1000 times below the threshold at which the chemical could cause reproductive harm.
Unintended Consequences of Prop 65: Vegetables and Herbs with Warning Labels?
The designated “safe” thresholds set by Prop 65 are very low, as indicated above. In many cases, they are lower than the EPA’s “safe limits” set for various chemicals. This feature of Prop 65 has several unintended consequences. For one, the low thresholds set by Prop 65 encompass many herbal products because herbs can absorb low levels of heavy metals and other chemicals from the soil as they grow. However, if we are to place Prop 65 warnings on herbal products, then we should, in all honesty, place warnings on organically-grown vegetables, too, since these foods can also absorb heavy metals and other Prop 65 listed chemicals from the soil. For example, a lb. of organic or conventionally grown carrots may contain approximately 1.95 mg of lead. (2) Fresh collard greens can contain up to 30 mcg of lead (50x higher than Prop 65 stipulates!), dry roasted mixed nuts up to 20 mcg of lead, Brussels sprouts up to 15 mcg of lead, sweet potatoes up to 16 mcg of lead, and spinach up to 15 mcg of lead. Clearly, even healthy, whole foods can constitute a significant source of lead exposure yet are not required to wear a Prop 65 warning! (3)
Prop 65 Labels on Other Natural Products
While we don’t have warning labels on our organic produce, Prop 65 warning labels are required on many herbal products, including those from reputable companies that routinely monitor and control the levels of metals in their products. Supplements containing certain nutrients, such as vitamin A (retinyl ester), may also require Prop 65 warnings, even though vitamin A has only been shown to be toxic at very high dosages of 100,000 IU per day over a six-month timeframe. Natural products other than herbs and vitamins, such as bentonite clay and zeolite, may also require Prop 65 warnings since these compounds are derived from mineral-rich rocks in the Earth’s crust that may contain trace amounts of heavy metals. However, a comparison of the lead level in bentonite clay, for example, and that found in old lead water pipes or lead paint chips, clearly demonstrates that the level found in bentonite clay magnitudes lower than the pipe and paint exposures. Quicksilver Scientific Ultra Binder contains bentonite clay, and each batch is tested for heavy metals by a third-party lab before we release the product. The specified limit for lead in Ultra Binder is less than or equal to 10 ppm. If a specific batch of Ultra Binder comes back with a lead level of 10 ppm and Ultra Binder is consumed as directed at a dose of 1 tsp per day (which weighs four grams), then 40 µg of lead may theoretically be consumed. (4, 5) The intake threshold set by Prop 65 for lead is 0.5 µg per day. This extremely low threshold necessitates that Ultra Binder carry a Prop 65 warning label. For reference, other sources of lead that constitute a far more significant exposure include water pipes and systems, chips from old lead paint, art supplies, colored glass kits, bullets, fishing sinkers, balance weights, radiation shields, lead-acid batteries, bearing alloys, contaminated herbal preparations and teas (as opposed to cGMP certified supplements such as those sold by Quicksilver Scientific), and certain ceramic glazes or pigments. Furthermore, the FDA upper limit for lead intake in adults is 12.5 µg, a less stringent threshold compared to that set by Prop 65.
Quicksilver rigorously tests each batch of Ultra Binder® for heavy metals by a third-party lab during the production process. The lab uses state-of-the-art inductively coupled plasma mass spectrometry (ICPMS) to ascertain the levels of heavy metals in each sample. The third-party lab specifies the following limits for arsenic, cadmium, lead, and mercury:
Concentration (in ppm)
≤ 5 ppm
≤ 1 ppm
≤ 10 ppm
≤ 1 ppm
Products Labeled with Prop 65 Warnings Are Not Universally Unsafe
The presence of a Prop 65 warning on a product does not automatically mean that the product will cause cancer or reproductive harm if it is used as directed. High-quality supplement companies take every measure to ensure their products’ safety, and Quicksilver Scientific is no exception. If you see a Prop 65 warning label on a supplement, it does not mean that the supplement is harmful when used as directed and indicates that the supplement company is compliant with the law.