When you look on a food or supplement label, chances are you’ll see ingredients you’ve never heard of. Some you might not even be able to pronounce. Though several of these may make you feel hesitant or suspicious, others are safe, and it’s merely their name that’s off-putting.

Silicon dioxide is one such ingredient. It’s found in many products, though is often misunderstood.

Silicon dioxide (SiO2), also known as silica, is a natural compound made of two of the earth’s most abundant materials: silicon (Si) and oxygen (O2).

Silicon dioxide is most often recognized in the form of quartz. It’s found naturally in water, plants, animals, and the earth. The earth’s crust is . It makes up more than 95 percent of known rocks on the planet. When you sit on a beach, it’s silicon dioxide in the form of sand that gets between your toes.

It’s even found naturally in the tissues of the human body. Though it’s unclear what role it plays, it’s thought to be an essential nutrient our bodies need.

Silicon dioxide is found naturally in many plants, such as:

  • leafy green vegetables
  • beets
  • bell peppers
  • brown rice
  • oats
  • alfalfa

Silicon dioxide is also added to many foods and supplements. As a food additive, it serves as an to avoid clumping. In supplements, it’s used to prevent the various powdered ingredients from sticking together.

As with many food additives, consumers often have concerns about silicon dioxide as an additive. However, numerous studies suggest there’s no cause for these concerns.

The fact that silicon dioxide is found in plants and drinking water suggests it’s safe. has shown that the silica we consume through our diets doesn’t accumulate in our bodies. Instead, it’s flushed out by our kidneys.

However, the progressive, often fatal lung disease silicosis can occur from chronic inhalation of silica dust. This exposure and disease primarily occurs among people who work in:

  • mining
  • construction
  • quarrying
  • the steel industry
  • sandblasting

While many of the on silica have been done on animals, researchers have found no link between the food additive silicon dioxide and increased risk of cancer, organ damage, or death. In addition, have found no evidence that silicon dioxide as an additive in food can affect reproductive health, birth weight, or bodyweight.

The has also recognized silicon dioxide as a safe food additive. In 2018, the urged the European Union to impose stricter guidelines on silicon dioxide until further research could be done. Their concerns focused on the nano-sized particles (some of which were smaller than 100 nm).

Previously guidelines followed a prepared in association with the World Health Organization. This paper found the only negative health effects related to silicon dioxide have been caused by silicon deficiency. More current research may be changing the guidelines and recommendations.

Though the research so far suggests there aren’t many risks associated with silicon dioxide ingestion, the has set upper limits on its consumption: Silicon dioxide shouldn’t exceed 2 percent of a food’s total weight. This is mainly because amounts higher than these set limits haven’t been sufficiently studied.

Silicon dioxide exists naturally within the earth and our bodies. There isn’t yet evidence to suggest it’s dangerous to ingest as a food additive, but more research is needed on what role it plays in the body. Chronic inhalation of silica dust can lead to lung disease.

People who have serious allergies have a vested interest in knowing what additives are in the foods they eat. But even if you don’t have such allergies, it’s best to be cautious with food additives. And even minor changes in levels of minerals can have a profound effect on healthy functioning. A good approach is to eat whole foods and get healthy levels of silicon dioxide.