The Impact of Smell on Hand Sanitizer Effectiveness

During the ongoing COVID-19 pandemic, there has been a noticeable rise in hand sanitizers with a distinctive, often off-putting smell. This phenomenon is not only concerning for those who find the smell disagreeable but also prompts the question: does a foul smell indicate that a hand sanitizer is ineffective?

Why Foul-Smelling Hand Sanitizers Are More Common

The off-putting smell—often described as rotten garbage or tequila-like—is a natural byproduct of ethanol production. Ethanol is a key ingredient in most hand sanitizers, and it is derived from corn, sugar cane, beets, and other organic sources. As such, the smell is a result of the unrefined nature of the ethanol being used in these hand sanitizers.

Many of the hand sanitizers with this distinct smell are produced by distillers who have switched from making drinking alcohol to producing hand sanitizer. These manufacturers use denatured ethanol to cut costs. Denatured ethanol is less expensive and does not require the use of activated carbon filtration, a process that typically removes contaminants and unwanted odors.

The Role of Ethanol in Hand Sanitizers

Ethanol is the active ingredient in hand sanitizers that effectively kills viruses and bacteria. However, there are concerns about the quality of ethanol used in less expensive, off-brand hand sanitizers. If the ethanol is not of sufficient purity, it can render the hand sanitizer ineffective at fighting germs. This is why it is critical to ensure that the hand sanitizer you use contains a high percentage of alcohol to be effective.

Testing for Effectiveness

There are straightforward methods to test the effectiveness of your hand sanitizer at home. One simple test involves:

Using a clean glass plate. Putting four or five drops of the hand sanitizer in a single spot at the lowest point on the plate. Using a lit match and placing it on the spot where the sanitizer drops are. Ensuring that a bluish flame is visible above the spot where the sanitizer drops are. Observing whether the match sizzles or is immediately extinguished by the sanitizer.

If the sanitizer does not burn or the match is immediately extinguished, it likely contains insufficient alcohol and may not be effective in killing germs. A sanitizer that passes with a small flame indicates a higher concentration of alcohol and is more likely to be effective. Comparatively, a 100 proof alcohol burns much better than an 80 proof at 80% and 40%, respectively.

Conclusion and Recommendation

Given the importance of using effective hand sanitizers, it is crucial to be mindful of the smell and the test results for your hand sanitizer. If the hand sanitizer smells foul or fails the flame test, it is best to discard it, even if you have used it before.

For those who are sensitive to the smell or want a more reliable and effective product, it is recommended to buy higher-quality hand sanitizers, such as Purell, which ensure both effectiveness and pleasant use. You can verify the composition and effectiveness of your hand sanitizer through simple at-home tests and ensure you are using a product that will protect you effectively against germs and viruses, including COVID-19.