(NEXSTAR) — With the rise in coronavirus cases, the Food and Drug Administration has noted a simultaneous increase in the number of hand sanitizer products being made. Though the Centers for Disease Control and Prevention recommend using hand sanitizer when hand-washing is unavailable, not all of them are made the same.

The FDA says that, in some cases, the differences can be life-threatening. Since August, they’ve been adding to a list of hand sanitizer products and companies who have manufactured sanitizer that is “labeled to contain ethanol (also known as ethyl alcohol) but that have tested positive for methanol contamination.”

Here’s why that matters: Methanol—also known as wood alcohol—can be toxic when absorbed through the skin. If ingested, the FDA says it can also be “life-threatening.” Enough exposure could cause nausea, vomiting, headaches, blurred vision, blindness, seizures, nervous system damage, coma, or even death.

“The agency is aware of adults and children ingesting hand sanitizer products contaminated with methanol that has led to recent adverse events, including blindness, hospitalizations and death,” the agency noted on their website.

Children who accidently ingest hand sanitizer and those who may purposefully drink the substance as an alcohol substitute are the most at-risk. So what should consumers be looking for?

Though the agency noted that its “investigation of methanol in certain hand sanitizers is ongoing,” it has made the full list available:

Some other things the FDA is watching for, according to its website, include the following:

  • The dangers of drinking any hand sanitizer under any conditions. While hand sanitizers with possible methanol contamination are more life-threatening than those that are not contaminated, FDA urges consumers not to drink any of these products. 
  • Certain hand sanitizers that may not contain a sufficient amount of ethyl alcohol or isopropyl alcohol.
  • Hand sanitizers that are sold or offered for sale with false and misleading, unproven claims that they can prevent the spread of viruses such as COVID-19, including claims that they can provide prolonged protection (e.g., for up to 24-hours).
  • Products that are fraudulently marketed as “FDA-approved” since there are no hand sanitizers approved by FDA.
  • Products packaged to appear as drinks, candy or liquor bottles, as well as products marketed as drinks or cocktails because their appearance could result in accidental ingestion or encourage ingestion. Children are particularly at risk with these products since ingesting only a small amount of hand sanitizer may be lethal in a young child.
  • Products labeled with harmful or poisonous ingredients, such as methanol.