Lukas Flippo, Photo Editor

On March 26, students, faculty and staff were notified in an email from Yale’s Environmental Health & Safety Department, or EHS, that benzene, a substance that can cause cancer, was detected in two hand sanitizer brands distributed by Yale, CleanHands and ArtNaturals, and were asked to dispose of the hand sanitizers immediately.

The contamination was first identified by the independent analysis lab Valisure, which filed a Food and Drug Administration, or FDA, citizen petition on March 24 after finding benzene in samples from 44 hand sanitizer products. Valisure, which is located in New Haven’s Science Park, conducts regular chemical testing of chemical and pharmaceutical products in the U.S. supply chain. In reaction to the discovery, many members of the Yale community have expressed concern for their health and safety.

“It’s incredibly alarming to find out that we’ve all been rubbing a carcinogenic chemical into our skin multiple times a day,” Kendall Oliver ’22 wrote in a message to the News. “I understand that the manufacturers were scrambling to keep up with the increased demand for hand sanitizer, but that’s no excuse to cut corners.”

ArtNaturals and CleanHands did not respond to a request for comment.

According to the National Institute for Occupational Safety and Health, or NIOSH, benzene is a carcinogen that can cause harm through ingestion, inhalation, skin absorption and contact with eyes. Although normal FDA guidelines advise against the use of benzene to manufacture products like hand sanitizer, the unprecedented demand for hand sanitizer caused by the COVID-19 pandemic led to a loosening of those guidelines, with the FDA allowing a limit of two parts per million, or ppm, for benzene in liquid hand sanitizers.

However, when Valisure tested 260 different hand sanitizer products from around the country, they found 44 samples that contained more than two ppm of benzene, which could present a serious risk to human health. The highest level of benzene detected among all the products was 16.1 ppm in the ArtNaturals brand, one of the products distributed by Yale.

“We initially tested hand sanitizers from our own suppliers for their pharmacy, and as soon as we started seeing an issue, we did a market-wide sweep,” founder and CEO of Valisure David Light ’08 said. “For hand sanitizers, we went to local big-name shops and retailers, and went online to places like Amazon to get as many products as the average American buyer. Of course, this isn’t a perfect representation of the entire U.S., but we tried to be as unbiased as possible.”

To test for benzene in the hand sanitizers, Valisure used gas chromatography mass spectrometry, or GCMS, a chemical analysis technique and industry standard recommended by the FDA for hand sanitizer testing. According to Light, this technique allowed for high resolution identification and quantification of benzene in the different samples.

After detecting benzene in 44 of the samples, Valisure validated their findings through the Yale Chemical and Biophysical Instrumentation Center, or CBIC. Although Valisure is not directly associated with the University, it was founded by two Yale graduates, Light ’08 and Adam Clark-Joseph ’07. In order to keep the analysis techniques consistent when verifying the results, the CBIC also used the GCMS method.

“Valisure reached out to confirm 19 samples, out of which I found 15 with elevated amounts of benzene,” CBIC chemist Fabian Menges said. “After EHS heard about the study published by Valisure, they reached out to our lab to run 15 different samples that were representative of the hand sanitizers distributed at Yale. We found some amount of benzene in two samples from the ArtNaturals and CleanHands brands, which caused that recall from EHS.”

Menges stressed that the contamination is not consistent, as different samples from the same brand produced different results. According to Menges, such results indicate that this situation is due to a mass-producing casualty in which certain batches are contaminated, while others remain safe.

Menges speculated that the contamination could have been caused by a bad barrel of raw material that was not properly tested when received by the hand sanitizer producer from an unreliable vendor. These harmful materials could then be passed down in the production line into the final hand sanitizer product. This is why, according to Menges, batch-to-batch quality control is essential throughout the production process.

Light echoed Menges’ call for better quality control in the industry, specifically the need for independent testing of products like hand sanitizer.

“Other than Valisure, there is no independent layer of quality assurance for these kinds of products, which is a fundamental problem for not only hand sanitizer but in general,” Light said. “We are really pushing for buyers like Yale and other large institutions to have this layer of independent quality assurance before buying these products.”

According to University spokesperson Karen Peart, the University does not expect any health issues to arise in the community from this “extremely low level” of benzene. However, the University is taking immediate action to ensure the health and safety of students, faculty and staff.

When asked about the implications of benzene being found in hand sanitizer, which is made for use on the skin rather than ingestion, Menges pointed out two possible situations in which benzene could in fact enter a person’s body. He first said there is a chance that the solvents used in hand sanitizer could dissolve through a person’s skin. Another possibility is that the low vapor pressure of certain solvents, like ethanol and isopropanol, could cause someone to inhale the benzene as the hand sanitizer evaporates quickly off of one’s hands.

The EHS message sent out to the Yale community on March 26 called for the disposal of all hand sanitizers from the two brands ArtNaturals and CleanHands.

“Yale is collecting all of the contaminated hand sanitizers and will dispose of them as hazardous waste at a commercial EPA-permitted facility for managing hazardous waste,” Peart wrote in an email to the News.

Valisure is located at 5 Science Park.

Veronica Lee |

Anjali Mangla |

Veronica Lee covers breakthrough research for SciTech. She is a sophomore in Branford College majoring in molecular, cellular, and developmental biology.
Anjali Mangla is a Science & Technology Editor for the News. She previously covered the intersection of STEM and social justice. Anjali is a sophomore in Ezra Stiles College planning to study Neuroscience, Global Affairs and Global Health Studies.