Growing Naturals’ Heavy Metals Management Program

LAST UPDATED January 2023

To: Our Valued Customers

From: Growing Naturals' Quality Team

The subject of lowering heavy metals in our rice and pea proteins has been a key initiative addressed by Growing Naturals since 2011. Although there is no such thing as being 100% metal-free (for ANY food), we have been committed to lowering its naturally occurring heavy metal levels year after year. Our goal is to lower the levels faster than any external trends, while relying upon the speed of current research and technology that still maintains the natural structure of our product. As a proud manufacturer of organic brown rice protein, we would like to provide you reassurance and safety in regards to the heavy metals in our rice protein supplements.

Why are there heavy metals in rice/pea protein? In short, metals occur naturally in ALL soils and thus get absorbed by any vegetation including rice plants (much like any other nutrients like calcium, iron and magnesium are absorbed). For further information, please see our article on "How did heavy metals get into my food/supplement?"

What are the levels of heavy metals in your rice/pea protein? We have always thoroughly tested all our products to ensure we do not release any product with high heavy metals. We do test each batch for heavy metals and our levels are very low. We are currently meeting the following criteria of heavy metals in our products:

Cadmium - (less than) < 0.30 ppm (parts per million)

Lead - (less than) < 0.25 ppm

Arsenic - (less than) < 0.20 ppm

Mercury - (less than) < 0.045 ppm

Although exact amounts vary from batch to batch, each metal will be below the above referenced levels. If you would like to know the exact level in your product, please email us and note the specific lot# printed on the bottom of your canister.

Why is Prop 65 on your rice/pea protein canisters? Prop 65 refers to a law enacted by the State of California for California residents only. The proposition was intended to protect California residents and the state’s drinking water sources from chemicals (including lead) known to cause cancer, birth defects, or other reproductive harm, and to inform citizens about exposures to such compounds via label warnings, no matter how infinitesimal or trace the exposure.

Because water is essential to life and may be consumed in copious amounts, the limit for chemical exposure in Prop65 was set extremely low. So low that amounts found naturally in healthy produce like spinach, avocado, nuts, etc. would be considerably higher than the established limit. And while such produce would warrant a Prop65 warning, they are exempt because of their status as whole fresh food.

Prop65 has since expanded to apply to any products sold in the state of California and warning signs are even commonly seen at every Starbucks.

While we, Growing Naturals, stand by the safety of our products, we had to place the labels on our rice protein canisters to abide by California law. In fact, we are so sure of its safety that all of our team members (and family members) consume this on a near daily basis.

How are you keeping metal levels down? We have worked closely with our supplier to influence the need for and identify geological areas that inherently have less naturally occurring heavy metals (vs. areas with higher levels due to historic volcanic activity, pollution etc.) for growing organic certified rice such as Cambodia and Vietnam. We have continuously tested products from raw material to protein powder at accredited laboratories, utilizing the newest and most reliable standards, to ensure accuracy and thus quality. Additionally, we have worked with a team of scientists to develop new procedures and technologies to limit the level of heavy metal at every stage, while still maintaining the natural status of the final protein powder.

Why don’t you source rice from the US? Unfortunately, the US does not produce enough Organic rice for us to use. According to the USDA, the US produces less than 2% of the world’s rice supply and about half of what it does produce is exported to other countries like Mexico and Japan (4). Out of the other half, only 6% is organically produced and about two-thirds are sold for consumption in its whole grain form (5). The remaining third is divvied up for processed foods, pet food and beer.

Do you test for tungsten? The United States Food and Drug Administration (FDA) has indicated that when tungsten is detected as an elemental impurity in pharmaceutical products it does not need to be subjected to a health risk assessment due its “low inherent toxicity” (1). Tungsten is a naturally occurring metal found in soil and concentrations in soil may range from less than 1 ppm to 83 ppm (2). Tungsten has not been classified by US Environmental Protection Agency as a carcinogenic chemical. Based on concerns from previous years related to tungsten in rice protein products, we tested multiple batches of our products with accredited labs. We did find a small amount of tungsten in one batch of rice protein only, but otherwise have found only trace amounts of tungsten in our rice protein powders.

Out of concern for our customers and our concern for safety as a whole, we had a toxicity study performed based on the highest levels of tungsten found in our rice protein powders. The results of the study performed on Growing Naturals Rice Protein showed that even at the maximum level of tungsten found, they are safe for daily consumption and will not cause any harmful effects. This study used data from the Agency for Toxic Substances and Disease Registry and used the No Observed Adverse Effect Level for tungsten based off the study of tungsten in drinking water (3). This study was based on an uncertainty factor of 100 times or more in magnitude so we are very confident our rice proteins are not a risk to safety.

Consumer Education: We believe consumers can make better decisions for their well-being by having a well-rounded education about the positives and negatives of heavy metals and rice proteins. In conjunction with our ingredient supplier, Growing Naturals is embarking on a consumer education program to help buyers make informed decisions. Our goal is to educate consumers about more beneficial plant-based alternatives to the dairy products tens of millions of people cannot utilize due to intolerances, allergies or health benefits.

Programs included: • Press releases distributed to general and niched media contacts. • A national consumer media tour and online education program, featuring Dr. Janet ( and other experts. • General educational articles and research available for sharing, which can be found on Visitors can go directly to for study-based information and for contributions from experts, including Growing Naturals’ in-house Registered Dietitian.

  1. 2013. International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use. Draft Consensus Guideline. Guideline for Elemental Impurities. Q3D. July 26, 2013.
  2. 2005. Toxicological Profile for Tungsten. Center for Disease Control and Prevention. Atlanta.
  3. Schroeder, H.A. and M. Mitchener. 1975. Life-term studies in rats: Effects of aluminum, barium, beryllium, and tungsten. Journal of Nutrition 105: 421-427
  4. Boriss, H. Rice profile. Agricultural Marketing Resource Center, US Department of Agriculture. July 2013. Available at:
  5. US rice domestic usage report: Milling Year 2011-2012. USA Rice Federation. Available at:

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