Not necessarily! When considering a Prop-65 label on a packaged food, it's important to remember that Prop 65 is a right-to-know law, not a safety law. While the language of the warning is stark, it’s not intended to scare away a consumer, but to inform them of the presence of chemicals above a conservative, state-established threshold. From there, the consumer can determine for themselves their comfortability with the product, considering their personal health status, exposure to toxins on a day-to-day basis, and the source and type of chemical occurrence. In most cases, this means reaching out to the manufacturer or business to learn more about what triggered the warning.
Prop 65 warnings are required for chemical amounts that occur far below any levels of concern for the FDA, EU, and other governing bodies. For example, the chemical level that requires the warning about possible reproductive harm or birth defects is 1,000 times lower than the level that has been shown in rigorous studies to cause no observable harm.
Determining the safety of a product with a Prop 65 warning can require a bit of detective legwork. The label currently does not disclose the amount of a chemical in a product, nor does it share its origins (as of 2018, however, it does require the specific name of the chemical to be listed on the label of new products).
And while the warning be the same from product to product, it's not necessarily apples to apples. On a child's Halloween custome,, for example, you might be warned about chlorinated tris, a synthetic, flame-retardant chemical designed to keep a child safe from flaming jack-o-lanterns. This chemical—one in a class of tris chemicals abbreviated as TDCPP—is also widely used in flexible polyurethane products, like upholstered furniture and the headrests of cars. As these products age, they release chlorinated tris into the environment, which can be measured in the dust and air of living places—and in human adipose tissue. This is a health concern for everyone, but especially so for crawling babies, who sweep the floor with their movement and may consume traces of chlorinated tris in their mother's breast milk as well.
Numerous rodent studies have linked exposure to chlorinated tris with cancer development. In addition a retrospective cohort cancer mortality study that looked at workers at a TDCPP manufacturing plant from 1956-1980 saw ten deaths from cancer among 289 workers. While the authors of the study determined that they were unable to draw conclusions from these statistics due to confounding factors, they confirmed that the fatality rate from cancer was higher than expected when compared to a similar population of U.S. males without higher than average TDCPP exposure.
Another product on which you might find the Prop 65 label is a bar of organic, herbal soap. Here, instead of chlorinated tris, you might see β-myrcene as the chemical listed. Beta myrcene is a compound found naturally occurring in some plants, such as lemongrass, carrots, hops, and parsley, and found in foods and body care products that use flavor extracts or essential oils from these plants. Beta myrcene is also manufactured as an additive to polymers and other synthetic products.
In 2014, beta-myrcene was proposed for the list of Prop 65 carcinogens, much to the consternation of carrot farmers, makers of body care products, and, extract manufacturers who argued that the evidence used to support the cancer link was insufficient and inaccurately reported on. Regardless, the proposal passed the following March 2015 and beta-myrcene now falls under Prop-65 labeling requirements for cancer causing chemicals.
While the outcome of rodent studies feeding concentrated amounts of these two chemicals might both yield cancerous outcomes, the difference between chlorinated tris and beta myrcene is significant; one is a synthetic chemical that seeps into its surrounding environment, while the other is primarily a naturally occurring chemical found in plants and their essential oils, often used in topical products like soaps. Yet both require the same warning label on products that exceed their safe harbor levels. Prop 65 law is clear, however: its job is to warn a consumer of chemical exposure, not to inform on the safety of a product.
When it comes to some of our superfoods, the Prop 65 warning label is required due to trace amounts of heavy metal elements that are absorbed from the organic soils in which the superfoods are grown. These metals occur naturally in soils around the world and are absorbed in by plants growing in them to varying degrees, depending on the type of plant and the part of the plant that's being measured. It’s important to note that the Prop-65 warning on our foods is not a result of farming practices, processing, manufacturing, or packaging, and in order to ensure their safety and quality we use third party, independent labs to test all of our superfoods for heavy metals, microbials, and nutrition.