Soylent FAQs

Why should we worry about lead and cadmium?

The California Office of Environmental Health and Human Hazard Administration (OEHHA) has listed cadmium and lead as chemicals known to cause birth defects or other reproductive harm.1

Lead exposure has been a significant public health issue for decades and is associated with neurological impairment, such as learning disabilities and lower IQ, even when ingested at low levels.3, 4, 5  “Pregnant women and young children with developing brains in particular should avoid any ingestion of lead” asserts Sean Palfrey, MD, professor of Pediatrics and Public Health at Boston University School of Medicine.

Chronic exposure to cadmium can cause kidney, liver, and bone damage in humans. Cadmium may also cause developmental problems, such as decreased birth weight, harm to neurobehavioral development, and male reproductive toxicity, all of which have been observed in animal studies.6, 7

Lead and cadmium accumulate in the body over time, increasing the total body burden of these heavy metals over decades. Ingesting even small amounts of these metals will add to existing body burdens and should be avoided.3, 4, 5, 6, 7. Since Soylent is marketed as a meal replacement, consumers may be chronically exposed to elevated levels of lead and cadmium.

Does Soylent contain lead and cadmium?

As You Sow commissioned an independent state-certified laboratory to conduct testing on samples of Soylent 1.5.  The results showed that lead and cadmium were present in each sample of Soylent 1.5 product that As You Sow submitted.

Proposition 65 requires that a warning be provided to consumers when lead and cadmium are present in a product.  Where defendants can demonstrate that their product does not expose consumers to these metals above the Safe Harbor Level set by the State of California, they are not required to warn. Assuming consumption of a single serving of Soylent 1.5 per day (as printed on product label (115 g)), in the samples that As You Sow tested, one serving of Soylent 1.5 would expose a consumer to a concentration of lead that is 7.6 to 25.3 times greater than California’s Safe Harbor level for reproductive health, and a concentration of cadmium that is 1.4 to 5.9 times greater than California’s Safe Harbor level for reproductive health. The Safe Harbor Level of Proposition 65 is also known as a “Maximum Allowable Dose Level” (MADL). For more info on California’s safe harbor levels, see The MADL for lead is set at 0.5µg/day and 4.1µg/day for cadmium.

Soylent’s Own Test Results

Soylent commissioned an independent lab (Covance) to test its Soylent 1.5 product. Its own test results show that the product contains a concentration of 0.0434 ppm of lead. At one serving of the product (115 grams), the product contains lead at a concentration that is 9.9 times greater than California Proposition 65’s Safe Harbor Level for reproductive health (0.5ug/day) and cadmium at a concentration that is 5.2 times greater than the daily safe harbor level for reproductive health (4.1 ug/day).

The lead concentration of 0.043 ppm in their tested Soylent 1.5 product, as reported by Soylent, is at least 4 times greater than the Codex Alimentarius Commission (formed by the Food and Agriculture Organization of the United Nations (FAO) and the World Health Organization (WHO)) recommendation of lead in infant formula of 0.01 ppm (Ref 13) (See section below entitled: “Doesn’t the government protect us from chemicals like lead and cadmium in the products we buy? “).

Note: these comparisons are based on consumption of just one serving per day, and do not take into account consumers consuming more than one serving per day.

What is Proposition 65 and how is As You Sow enforcing it?

California Safe Drinking Water and Toxic Enforcement Act of 1986 is a consumer-right-to-know law voted into existence in 1986 by California citizens. As stated in the law’s preamble, “The people of California find that hazardous chemicals pose a serious potential threat to their health and well-being. . . .”  The Act protects Californians by requiring companies to warn consumers if their product exposes them to chemicals known to cause cancer and/or birth defects or other reproductive harm. While the law applies to persons doing business in California, the enforcement of the law has a positive impact on a range of consumer products available through the U.S. Many product manufacturers, when reformulating to reduce toxins for the California market, will then sell the same reformulated product across the U.S. and even globally.

In issuing this Proposition 65 notice, As You Sow seeks to encourage the company to identify the sources of heavy metals in its Product and take action to reduce or remove these toxic heavy metals, or to provide warning to consumers as required under California’s Proposition 65.

For over 23 years, As You Sow has been successfully enforcing the California Safe Drinking Water and Toxic Enforcement Act of 1986 and has worked with manufacturers to provide warnings to consumers and/or reformulate hundreds of products in order to provide the consumer with a cleaner, healthier product. These actions include mercury in fish; toluene in nail polish; lead in herbal supplements; formaldehyde in portable school classrooms; and toxic chemicals in cosmetics and laundry detergent, among others. You can see a list of some of these products on our Toxic Enforcement page.

Doesn’t the government protect us from chemicals like lead and cadmium in the products we buy?

The FDA does not consistently monitor food for lead and cadmium contamination, and has not set any regulatory “action levels” for lead or cadmium in food. In contrast, California has the most health protective standards in the country for the presence of lead and cadmium in consumer products. The only ‘action levels’ that the FDA has issued for lead and cadmium in food-related products, are for lead leaching from “ceramic ware” and “silver-plated hollowware”) and cadmium leaching from “pottery (ceramics)”.10,11 With regard to food guidelines, the FDA has issued only recommended “guidance for industry” for lead concentrations in candy.12 These FDA “action levels’ as well as the “guidance for industry” were set after, and perhaps in response to, Proposition 65 litigation concerning these product categories

In 2014, the Codex Alimentarius Commission, a commission established by the Food and Agriculture Organization of the United Nations (FAO) and the World Health Organization (WHO) to develop harmonized international food standards, guidelines, and codes of practice, adopted a recommendation that no more than 0.01 mg/kg (or ppm) of lead should be permitted in infant formula. The previous standard was 0.02 mg/kg (ppm).13

What are the sources of lead and cadmium?

Cadmium and lead are toxic heavy metals that are released into the environment through manmade industrial processes including mining, burning fossil fuels such as coal or oil, incineration of municipal waste (plastics/batteries), and manufacturing and smelting, the largest source of airborne cadmium. Cadmium and lead also enter soil through the disposal of sewage sludge, or the application of pesticides or phosphate fertilizers (which can contain high levels of cadmium).4, 7

Once released into the atmosphere, respirable-sized airborne particles attach to dust, can travel long distances, and will be deposited onto the earth, where they move easily through soil layers and can be taken up into the food chain. Once mined and introduced into the atmosphere, these heavy metals can move from air to soil to water, but do not break down easily and will remain for decades.4, 7

How are we exposed to lead and cadmium?

The main route of human lead and cadmium exposure occurs via ingestion from food as well as through contaminated water and soil.4, 7 Lead and cadmium in food are ubiquitous and do not seem to discriminate between natural, certified organic, and non-organic products. One or both of these metals have been found in various foods including baby foods (made with carrots, peaches, pears, sweet potatoes), dietary supplements, vitamins, protein powders, seaweed snacks, ginger cookies, packaged peaches/pears, various fruit juices, as well as chocolate.

Another way we are exposed to lead and cadmium is through inhalation from dust or pollution from industrial processes. Additionally, cadmium is present in cigarette smoke.

How can food product manufacturers prevent or reduce lead and cadmium contamination in their products?

There may not be a single remedy to remove lead and cadmium in food products. Manufacturers must understand the manufacturing practices and possible manmade sources of contamination and then take steps to identify the source(s) of the contamination. For example, the equipment used to process the product could be a source of lead or cadmium. Similarly, water used in processing, or shipping containers, may be high in lead. Pesticides may have been used in growing ingredients or soils may be contaminated with manmade lead due to nearby industrial polluters or aerial deposition. Once the source(s) are identified, suppliers and manufacturers can improve their practices; increase supply chain transparency; and effectively remove or reduce lead and cadmium from their final product.

How can I tell if lead or cadmium is in the food I purchase?

The only way to be sure about whether lead or cadmium is in a product is to have the product tested for heavy metals by a certified lab. However, under California’s Proposition 65, manufacturers must warn consumers if a product will expose them to chemicals known by the State of California to cause cancer and/or birth defects or other reproductive harm, or prove that the exposure is below the state’s Safe Harbor Levels. Other consumer information services also provide information about metals in food and supplement products.

Will I get sick if I eat Soylent products with cadmium & lead?

It is difficult to predict which chemical exposure(s) will trigger an adverse health effect in a person, with effects depending on exposure levels and biological and/or genetic factors. What we do know is that lead and cadmium are toxic heavy metals and accumulate in the body where they remain for decades. The first step in preventing exposure is to understand whether the toxic metal is in a food or a product. As with all chemical exposures, the most vulnerable populations are developing fetuses, children, the elderly, and those most impacted from working or living near industrial and manufacturing plants.


  1. California Office of Environmental Health and Human Hazard (OEHHA).
  2. National Research Council, Measuring Lead Exposure in Infants, Children, and Other Sensitive Populations. Washington, D.C.: National Academy Press, 1993, p. 1. Centers for Disease Control, Preventing Lead Poisoning In Young Children, October 1991.
  3. EPA 2013 Integrated Science Assessment for Lead.
  4. Agency for Toxic Substances and Disease Registry (ATSDR). Toxicological Profile for Lead. August 2007.
  5. NRDC: Our Children At Risk, The Five Worst Environmental Threats to Their Health. Chapter 3: Lead.
  6. Agency for Toxic Substances and Disease Registry (ATSDR). ToxFAQs for Cadmium. 2012.
  7. Agency for Toxic Substances and Disease Registry (ATSDR). Toxicological Profile for Cadmium. September 2012.
  8. Rankin CW, Nriagu JO, Aggarwal JK, Arowolo TA, Adebayo K, Flegal AR. Lead contamination in cocoa and cocoa products: isotopic evidence of global contamination. Environ Health Perspect. 2005;113:1344–1348. [PMC free article] [PubMed]
  9. Yanus RL, Sela H, Borojovich EJ, Zakon Y, Saphier M, Nikolski A, Gutflais E, Lorber A, Karpas Z. Trace elements in cocoa solids and chocolate: an ICPMS study. Talanta. 2014 Feb;119:1-4. doi: 10.1016/j.talanta.2013.10.048. Epub 2013 Oct 28.
  10. “Action levels for poisonous or deleterious substances are established by the FDA to control levels of contaminants in human food and animal feed.”(
  12. (