You may have noticed a Prop 65 warning panel on products containing Redmond Clay, such as Earthpaste. California requires this because Redmond Clay, like many natural products from the earth, contains some lead. You can learn more about Prop 65 here.
Humans and animals have been using natural bentonite clay for thousands of years, and it’s the base of a lot of Redmond Life products. As a natural product from the earth, clay contains trace amounts of earth-based elements, including lead. Because of this, the state of California requires that we include a Prop 65 statement on the label of any products containing Redmond Clay saying that the product may not be appropriate for some women and children.
When it comes to elements and the body, the amount and form of the element are key. Studies suggest that bentonite clay is structured in a way that is not absorbed by the body.
According to an FDA-funded study, "Apparently, very little, if any, bentonite is absorbed after oral administration and as much as 3 percent in the diet has no observable adverse effects on experimental animals . . . No adverse effects have been observed at dietary levels as high as 12 percent in experimental animals. The human therapeutic dose for diarrhea is about 250 to 1,000 mg per kg.” (See Evaluation of the Health Aspects of Bentonite and Clay (Kaolin) as Food Ingredients.)
Interestingly, there are studies showing that bentonite/montmorillonite clay has been found to "significantly reduce lead concentration of tissues in blood, brain, liver, bone, kidney and hair." See Effect of montmorillonite superfine composite on growth performance and tissue lead level in pigs.
Other studies (see a short list at the end of this article) show clay's ability to remove toxins such as lead, cadmium, aflatoxin, and others from the body. This is why some people concerned with lead and other environmental toxins seek out bentonite/montmorillonite clay and clay-containing products, even though there may be small amounts bound tightly to the natural clay.
We’re not saying that clay or clay-based products are right for everyone, just that there are many peer-reviewed studies on the potential benefits of clay. Clays have been used by humans and animals since the beginning, and continue to be studied for a variety of human and animal uses. As always, we want you to make the choice that's right for you when it comes to our clay-based products (and all of our products).
Effects of montmorillonite on Pb accumulation, oxidative stress, and DNA damage in tilapia (Oreochromis niloticus) exposed to dietary Pb–--Biological Trace Element Research 2010
Calcium montmorillonite clay reduces AFB1 and FB1 biomarkers in rats exposed to single and co-exposures of aflatoxin and fumonisin–Journal of applied Toxicology 2014
Montmorillonite ameliorates hyperthyroidism of rats and mice attributed to its adsorptive effect–European Journal of Pharmacology 2006
Montmorillonite adsorbs uric acid and increases the excretion of uric acid from the intestinal tract in mice–Journal of Pharmacy and Pharmacology 2009
Efficacy of dioctahedral smectite in treating patients of diarrhea-predominant irritable bowel syndrome–Journal of Gastroenterology and Hepatology 2007
Short-term safety evaluation of processed calcium montmorillonite clay (NovaSil) in humans–Food Additives and Contaminants 2005
Effects of montmorillonite on alleviating dietary Cd-induced oxidative damage in carp (Carassius auratus)--Biological Trace Element Research 2011