Silica gel is a moisture absorber or desiccant that comes in little packets labelled “do not eat.” So, you may wonder what happens if you do eat silica gel. Is it toxic? Why is there a warning?
What Happens If You Eat Silica Gel?
Usually, nothing happens if you eat silica gel. It’s not digestible, so it gets passed in feces. Silica is not toxic. In fact, it’s considered safe enough to use as a food additive and it naturally occurs in water, where it might act as a protective agent against senility. Silica gel is a form of silicon dioxide. Other types of silicon dioxide include quartz, sand, and glass. The difference between gel beads and glass is that the beads contains tiny nanopores that allow the material to absorb water and become a gel.
The Illinois Poison Control Center advises parents to give a child a few sips of water if they eat the beads. If a child or pet chokes on the beads, it’s a medical emergency and requires immediate attention.
Why Is There a Warning on the Label?
So, if silica gel isn’t toxic, why is there are warning not to eat it? The main reason is that the packets might pose a choking hazard to children and pets. Also, as the gel beads rub against each other within the packet, they produce some dust. The dust irritates the esophagus and stomach, potentially causing vomiting.
Silica Gel Health Risks
However, silica gel packets that change color to indicate moisture absorption can contain toxic chemicals. Eating them warrants a call to Poison Control. The gel beads may appear blue, yellow, green, colorless, or pink or be labelled as “indicator silica gel.”
One additive is cobalt(II) chloride. Cobalt chloride is blue when dry and pink when hydrated. In the past, it was used as a food additive, but is now a suspected carcinogen and known cause of cardiomyopathy. Methyl violet (crystal violet) is another common indicator. It changes colors either orange to green or else orange to colorless. Methyl violet is toxic and potentially carcinogenic, but it has medical uses in small doses. Neither cobalt(II) chloride nor methyl violet are likely to cause immediate illness if ingested, but it’s still a good idea to seek medical attention if a person or pet ingested indicator gel beads.
- Cho, Kwahghyun; Seo, Beomsok; Koh, Hyunseung; Yang, Heebum (2018). “Fatal Case of Commercial Moisture Absorber Ingestion.” BMJ Case Reports. bcr-2018-225121. doi:10.1136/bcr-2018-225121
- Lavon, Ophir; Yedidia Bentur (2015). “Silica Gel: Non-Toxic Ingestion with Epidemiologic and Economic Implications.” Israeli Medical Association Journal. 17(10): 604–606. PMID:26665312
- Mani, Sujata; Bharagava, Ram Nareh (2016). “Exposure to Crystal Violet, Its Toxic, Genotoxic and Carcinogenic Effects on Environment and Its Degradation and Detoxification for Environmental Safety.” In: de Voogt W. (eds) Reviews of Environmental Contamination and Toxicology. 237: 71-105. Cham, Switzerland: Springer. doi:10.1007/978-3-319-23573-8_4
- Morin, Y.; Tětu, A.; Mercier, G. (1969). “Quebec beer-drinkers’ cardiomyopathy: Clinical and hemodynamic aspects“. Annals of the New York Academy of Sciences. 156 (1): 566–576. doi:10.1111/j.1749-6632.1969.tb16751.x