Decorated with a black exclamation point inside a bright yellow triangle, many Californians have come across a food warning label attached with the link "www.P65Warnings.ca.gov."

It reads, "WARNING: This product can expose you to chemicals known to the State of California to cause cancer, birth defects, or other reproductive harm."

"P65" refers to Proposition 65, a California law dating back to 1986. In 1984, a report revealed that solvents used in the Silicon Valley tech industry leaked into the groundwater.

Led by prominent entertainment industry members, such as Jane Fonda and Whoopi Goldberg, the group campaigned for the Safe Drinking Water and Toxic Enforcement Act (Prop 65).

The goal behind Proposition 65 was to persuade companies to stop using carcinogenic chemicals in their products, and it seemed to do just that.

There were upgrades in faucets, water filters, and hair dyes, and major companies were forced to pay millions of dollars to settle consumer lawsuits.

However, companies began slapping P65 labels on products without testing them to protect against potential lawsuits, leading California to update the law in 2018.

Now, P65 labels must name at least one specific chemical from the list identified in the product, meaning companies have to test their goods before including the warning.

The number of chemicals under Prop 65 has grown to 900, but their danger has been questioned since the amounts being tested were far beyond what would go into a singular product.

Some chemicals that consumers should be warned about include alcohol, which can cause birth defects and cancer, and mercury, which has been linked to kidney disease.

Acrylamide is a naturally occurring chemical that forms when foods are cooked at high temperatures. It is most commonly found in processed plant-based foods.

Bisphenol A (BPA) is sometimes used to line cans and jar lids. BPA has been linked to cancer, but fortunately, its industrial use has greatly decreased in recent years.

The studies linking these chemicals to cancer don't necessarily reflect the real risk. The test rats were given 1,000 to 100,000 times more acrylamide than you'd find in any food.