Why Do Hand Sanitizers Suddenly Smell So Awful?

At the beginning of the coronavirus pandemic—just before the peak of rabid stockpiling, when toilet paper attained currency-level value—I placed an order from one of the few online sellers still offering hand sanitizer. It was an online retailer specializing in bulk apothecary supplies, and I had to wait over two months for the delivery of an industrial-size, 1-gallon plastic bottle containing 70% ethyl alcohol “specially denatured with a mild lavender scent.”

It was that or nothing. Shoppers had already picked the shelves clean of recognizable brands like Purell, Germ-X, and even local drugstore formulations. A search of Amazon’s usually ample inventory proved futile, except for $100-per-bottle listings from opportunistic resellers. With options so bleak, I was relieved to have some sanitizer on hand again as a precaution.

That relief was short-lived. Opening the bottle revealed what could only be described as the funky marriage of rotting corncobs paired with pungent notes of barnyard odors, a repulsive nose-wrinkling scent that lingered and wafted far and wide with every use.

You too may have noticed that the assorted new brands of hand sanitizers smell ... different. Various no-name brands have sprung forth to meet market demand, and many share a common trait: an unpleasant scent. Some exhibit an organic rot like the bottle I purchased, while others emit an acrid alcoholic sharpness prone to stinging the nose. None have been as benignly pleasant to use as brands purchased prior to the pandemic shortage.

Over the past few weeks, I’ve purchased bottles from several of these new brands in hopes of finding hand sanitizer that will kill germs without killing my senses, with little success. So I set out to discover, with the help of a few experts, why these new hand sanitizers stink.

To get to the bottom of this malodorous mystery, I spoke to Bryan Zlotnik of fragrance manufacturer Alpha Aromatics, Pamela Dalton from the Monell Chemical Senses Center, Samantha Williams, corporate communications senior director of Gojo (parent company of Purell), and Li Wong, a qualified vintage aromatherapist, environmental scientist and biologist, professional cosmetic formulator, and natural perfumer.

Although the origin of hand sanitizers is debated, waterless hand sanitizers for the general public really began in 1988 with the birth of Purell Hand Sanitizer, an easy-to-use concoction of 70% ethyl alcohol mixed with propylene glycol (a moisturizing compound) that not only simplified waterless washing but also masked most of the most disagreeable scents associated with using alcohol in gel form by including a mild proprietary citrus scent.

But here’s where the mystery begins today. While every bottle of hand sanitizer I’ve purchased in the past few months during these pandemic shortages has listed the same base of 70% ethyl alcohol as brands I used prior to the shortages, these new brands seem to smell noticeably unpleasant. And I’m not alone in noticing this change.

“I personally had never experienced bad-smelling hand sanitizer [until recently]. Our workplace uses Purell in dispensers placed every 20 feet, and it smells neutral,” noted Pamela Dalton, a senior scientist at the Monell Chemical Senses Center in Philadelphia. “Serendipitously, I went into my local CVS yesterday, and they had a gallon pump jug of sanitizer just inside the door. I used some and it smelled like those cowhide pieces that my dogs used to chew on!”

I contacted Bryan Zlotnik of Alpha Aromatics, a perfume manufacturer specializing in additive solutions used to mask unpleasant odors in sanitizers, for an explanation as to why there has been a sudden proliferation of unpleasant-smelling hand sanitizer.

“That off-putting smell—sometimes described as rotten garbage or tequila-like—is the natural byproduct of ethanol being made from corn, sugar cane, beets, and other organic sources,” explained Zlotnik. “[Ethyl alcohol] production is highly regulated. It stinks because these new brands—many made by distillers who’ve pivoted from producing drinking alcohol to meet public demand for hand sanitizer—are making and using denatured ethanol. This ethanol costs significantly less than ethanol filtered using activated carbon filtration, which would typically remove almost all contaminants and the malodor with it.”

Those organic contaminants aren’t the only reason unfiltered and denatured ethanol smells downright foul. According to Zlotnik, denatured ethanol is also intentionally tainted with an unpalatable cocktail of chemicals (denaturants) such as methanol, acetone, methyl ethyl ketone, and denatonium to make it undrinkable. In other words: The base material is intentionally stinky.

So should everybody be making their own hand sanitizer at home instead, as numerous social media how-to posts propose as an answer to the world’s sanitizing woes? Li Wong, a qualified vintage aromatherapist, environmental scientist and biologist, and professional cosmetic formulator, does not think so.

“I do not recommend that the average person make their own hand sanitizer. Nearly every single recipe I have seen online or on the news has been improperly formulated,” she said. “If you are in a pinch, I suggest either using ethyl alcohol or isopropyl alcohol in a spray bottle (the alcohol concentration needs to be at least 60% alcohol to be effective). Or use the World Health Organization’s formulations (PDF).”

What if you’re already stuck with a handmade bottle, or a gallon of hand sanitizer polluted by malodor? Is there anything you can add to hand sanitizer to mask the smell? Li Wong advises not to add anything to hand sanitizers, as adding too much could compromise the formula.

But Bryan Zlotnik of Alpha Aromatics sees this as an opportunity. A masking agent developed by Alpha Aromatics originally for industrial use will soon be available to the general public and sold in small quantities to counteract the funky fragrance of pandemic-era sanitizer. “We recommend adding only 0.5%-2% by weight, depending on how strong you want the fragrance to be, but you should never dilute sanitizing solution to less than 60% ethanol in order to ensure its efficacy.”

Alpha Aromatics sent me a small sample to try out—and in spite of the dilution risks, I was curious to see if it at least worked for the smell. Adding 1% cucumber-scented solution neutralized most (but not all) of the malodor of the liquid sanitizer. The company is still fine-tuning how to make the dosage as easy and accurate as possible for the average person—remembering Li Wong’s warnings, I erred on the side of caution, adding only a dropper's dose into a large spray bottle, a minute amount that would not risk diluting the mixture anywhere near the 60% alcohol concentration baseline. For the time being, your safest bet is sticking with pre-formulated hand sanitizer, but try to comparison-shop (that is, sniff before you buy).

All that said, smelly hand sanitizer may have a silver lining: “The malodor is a potent behavioral message to keep our hands away from our face, which is something we should be doing anyway,” said Dalton. “While I normally do not want my hands to smell like a farm, it certainly did keep me from putting my hands anywhere near my face—and that could be a good thing!”