Since the emergence of coronavirus in the winter of 2020, people around the world have made hand sanitizer an essential purchase. But according to the Food and Drug Administration (FDA), the sales of certain sanitizers may be doing more harm than good. As Newsweek reports, many popular brands contain a dangerous chemical and shouldn’t be used by anyone.

Most effective hand sanitizers are made of at least 60 percent ethanol, which kills pathogens on contact. But the FDA has cautioned that many brands of sanitizer with poor quality control are made with methanol. While methanol is also effective in killing germs, it’s potentially toxic if ingested or absorbed through the skin. Signs of methanol poisoning include nausea, headache, and blurred vision. It can even cause death if ingested in large quantities.

While these products have ethanol listed as an ingredient, the FDA says they’ve tested positive for methanol contamination. Consumers are therefore being advised to avoid nearly 70 brands of sanitizer known to contain methanol. Brands include Blumen, Klar and Danver, Modesa, Assured, and LumiSkin. A complete list of products can be found on the FDA website.

[h/t Newsweek]