Meaning of "Proposition 65" warning listed on some of the products:

Proposition 65 is a statewide initiative passed in 1986 known as The Safe Drinking Water and Toxic Enforcement Act of 1986. This legislation was designed to address public concern about exposure to toxic chemicals. Proposition 65 requires that a list of chemicals which are known to cause cancer or reproductive harm be published by the Governor of California. Proposition 65 imposes certain controls over the listed chemicals, and is intended to allow California's consumers to make informed choices about the products they purchase.

The Governor of California's list contains over 700 naturally occurring and synthetic chemicals. Heavy metals are listed and are the grounds upon which Proposition 65 is being brought to bear on Chinese herbal medicine. Proposition 65 requires California businesses to provide a "clear and reasonable" warning before exposing anyone to a listed chemical. The warning reads: "WARNING: This product contains chemicals known to the State of California to cause cancer and/or birth defects or other reproductive harm." Proposition 65 applies to companies which operate in, or sell products into California. Even if a company has its own standards for heavy metals, it still must comply with the Proposition 65 warning requirements.

Comparison of the Prop 65 Standards vs National Standards

Lead is a naturally occurring element that is found in the environment, including soil. According to the EPA, natural levels of lead in soil can range between 50 parts per million (ppm) and 400 ppm. Human-spread lead contamination widens this range, of course, with reports of over 10,000 ppm in certain types of areas, such as industrial facilities. 

International standards for lead in dietary supplements and food are often set at no more than 5 ppm. The Prop 65 Safe Harbor Maximum Allowable Dose Level for lead is 0.5 micrograms per day, meaning that a person may not be exposed to lead above this amount, by any product, without a Prop 65 warning. Setting aside the difficulties of translating this exposure level to a concentration level in a specific product, applying this standard to herbs and supplements means that lead content levels would need to be many times lower than federal levels in order for a product to be sold without a Prop 65 warning. Above the Safe Harbor Levels, a Prop 65 warning must be given to avoid lawsuits and potential liability.

When grown in soil with a relatively “low” lead content (500 ppm), spinach and radishes can have lead levels that exceed 3 ppm, while beets and carrots can exceed 6 ppm. Also, herbs may contain over 90% water by weight, so lead levels in dried herbs can be up to 10 times higher than their fresh counterparts. In addition, it is difficult to get root crops entirely free of the soil they are grown in. Under these circumstances, it is easy to see how it might be difficult to keep lead levels low in natural herbal products and especially in herbal root products.

 For comparison

Lead Prop 65 warning required at 0.5 micrograms/serving and higher
FDA tolerable daily intake level
Adults: 75 micrograms
Children: 6 micrograms

A 4oz. serving of nuts, Brussel sprouts, or spinach can deliver up to 10 micrograms of naturally occurring lead. Indeed, virtually all foods contain lead and other heavy metals. In a study by the European Food Safety Authority the estimated mean lifetime dietary exposure from all sources to lead was estimated to be almost 50 micrograms per day in the overall European adult population. This is 100 times the Prop 65 limit. As you can see the potential amount of lead exposure from herbs and spices is at most a small amount of the total exposure to lead for the average person.

When manufacturing herbal products, it is often impossible to meet Safe Harbor levels. When Safe Harbor levels cannot be met Terrazure applies the appropriate Prop 65 warning to its labels.