Denatured alcohol — often abbreviated as “alcohol denat.” or “SD Alcohol” on ingredient lists — shows up in a lot of household products, from pharmaceuticals to paint remover. It kills germs, which is why it’s used in hand sanitizers and cleaning products, and is highly flammable, so it makes great fuel for camping stoves.
But is it safe to have in these household items? In general: Yes, as long as you absolutely don’t drink it.
Denatured alcohol is ethanol that’s been mixed with other ingredients. Ethanol — also known as grain alcohol — is alcohol at its most basic.
However, ethanol is dangerous to drink in large quantities, so it’s “denatured” with additional ingredients to discourage people from drinking it. (Introducing these ingredients also puts it in a different tax category, so it doesn’t cost as much to produce as the liquor behind the bar.)
Ethanol itself isn’t immediately toxic — it’s a byproduct of fermentation, so it does show up in the kind of alcohol you can buy at the corner store.
However, when consumed on its own, it is much, much stronger than the alcohol we usually drink.
While your average liquor is about 40 percent alcohol, ethanol hovers between 60 and 90.
If ingested, symptoms of alcohol poisoning will set in quickly. If you drink the same amount you’d put in a glass, it can kill you.
The good news is that manufacturers have done everything they possibly can to discourage you from drinking it — it’s purposely made to smell and taste bad. Not to mention the things they add during the denaturing process, like methanol (another simple form of alcohol, usually discarded during the distillation process), are even more toxic. Drinking methanol alone will cause paralysis and death — improper removal of methanol is what caused so many moonshiners to go blind during the Prohibition years.
While ethanol smells bad enough on its own, acetone, methyl ethyl ketone, and denatonium are often added to give it an offputting odor. Dye can also be added to distinguish it from other alcohols.
Denatured alcohol is sometimes used in cosmetics and skincare products (such as toners) as a drying agent: It dries quickly, neutralizes oil, and gives your skin a smooth, matte feel. In small amounts, denatured alcohol is usually no problem in cosmetics unless it’s mixed with methanol, which can seep in through the skin.
However, while denatured alcohol isn’t toxic at the levels needed for cosmetics, it can cause excessive dryness and disturb the natural barrier on your skin. Some studies suggest that denatured alcohol on skin may also cause breakouts, skin irritation, and redness.
A note of caution: Denatured alcohol can show up in products claiming to be “alcohol-free” through a sneaky marketing loophole. In FDA-approved parlance, “alcohol” only refers to ethanol. So once the alcohol in a product has been “denatured,” it’s no longer ethanol — and therefore, according to the strictest interpretation of FDA standards, is not alcohol.
That said, you don’t need to swear off all alcohols in skincare. There are some — known as fatty alcohols — that are actually good for your skin, like those derived from plants and fruits:
- stearyl alcohol
- cetearyl alcohol
- cetyl alcohol
These kinds of fatty alcohols are often added to skincare products as emollients, or moisturizing agents.
A small 2005 study with 35 participants suggests that adding emollients to alcohol-based hand rubs might decrease skin irritation, so if you’re worried about skincare products with denatured alcohol, look for one that also includes water, glycerin, or fatty alcohols.
If you look at the label of many commercial hand sanitizers, you’re likely to see “alcohol denat.” in the ingredients. But as people scramble for a supply of hand sanitizer in the age of COVID-19, some are making their own.
Skincare experts advice against this, as there’s an increased chance you’ll get the ratio of denatured alcohol to other ingredients wrong and use an unsafe amount — remember, denatured alcohol can contain methanol, which is poisonous if absorbed through the skin. (Healthline cautions against DIY-ing hand sanitizer for exactly this reason.)
On the other hand (no pun intended), if you use too little denatured alcohol in your recipe, it won’t be enough to sanitize your hands properly.
Experts agree the best way to sanitize your hands is simply to wash them for at least 20 seconds. If that’s not possible, use an FDA-approved hand sanitizing product.
Denatured alcohol is just basic alcohol, used in household products, that has ingredients added to ensure people don’t drink it for recreational purposes.
Despite its damaging effects when ingested, it is relatively safe when used in household products, even those that come in contact with your skin.
It’s an important ingredient in a lot of germ-killing products. Just don’t drink it.
Jody Amable is a freelance writer and editor from the San Francisco Bay Area specializing in music and subcultures. Her work has been seen in KQED Arts, Atlas Obscura, and local weeklies.