QR Codes On Baby Foods May Soon Show Heavy Metal Content

Parents all over the United States may soon be able to determine how much lead, arsenic, cadmium and mercury are in the food they feed their babies, thanks to a California law, the first of its kind, that took effect this year.

As of 1 January 2025, every company that sells baby food products in California is required to test for these four heavy metals every month. That comes five years after a congressional report warned about the presence of dangerously high levels of lead and other heavy metals in baby food.

Every baby food product packaged in jars, pouches, tubs and boxes sold in California must carry a QR code on its label that consumers can scan to check the most recent heavy metal readings, although many are not yet complying.

Because companies seldom package products for a single state, parents and caregivers across the country will be able to scan these QR codes or go online to the companies’ websites and see the results.

Soil naturally contains heavy metals. The earth formed as a hot molten mass. As it cooled, heavier elements settled into its center regions, called the mantle and core. Volcanic eruptions in certain areas have brought these heavy metals to the surface over time. The volcanic rock erodes to form heavy metal-laden soil, contaminating nearby water supplies.

Another major source of soil contamination is the exhaust from fossil fuels, and in particular leaded gasoline. Some synthetic fertilizers contribute, too.

Heavy metals in the soil can pass into foods via several routes. Plants that yield foods such as sweet potatoes and carrots, apples, cinnamon, rice and plant-based protein powder are especially good at extracting them from contaminated soil.

Sometimes the contamination happens after harvesting. For example, local water that contains heavy metals is often used to rinse debris and bugs off natural products, such as leaves used to make a widely used supplement called kratom. When the water evaporates, the heavy metals are retained on the surface. Sometimes drying products in the open air, such as cacao beans for dark chocolate, allows dust laden with heavy metals to stick to their surface.

Producers can reduce heavy metal contamination in food in several ways, which range from modestly to very effectively. First, they can reserve more contaminated areas for growing crops that are less prone to taking in heavy metals from the soil, such as peppers, beans, squash, melons and cucumbers, and conversely grow more susceptible crops in less-contaminated areas. They can also dry plants on uncontaminated soil and filter heavy metals out of water before washing produce.