If you're a fan of glossy, long-lasting gel nail polish but are concerned about the harmful UV light used to harden them, a new product that emerged from a University of California, Berkeley chemistry lab should ease your anxiety.
Magan's HandShield™, available since June, is a spray-on liquid that helps protect the skin from cancer-causing ultraviolet rays - UVA - emitted by LED lamps used to cure and harden gel nails, yet doesn't interfere with the hardening of the gel. The liquid comes in a travel-sized spray container that, if applied thoroughly, can last for about 25 applications to hands or feet.
The key ingredient is cerium carbonate, whose antioxidant properties were discovered in the research group of Alexander Katz, a UC Berkeley professor of chemical and biomolecular engineering, when he was investigating additives to slow oxidative UV damage. Cerium carbonate turns out to destroy harmful chemicals called reactive oxygen species (ROS), which UV light generates in skin and are responsible for the DNA damage that leads to cancer and aging in general.
Katz thought that cerium carbonate would be a good choice for helping protect the skin against short-term but intense UVA exposure like that during the application of gel nails, which can take up to 10 minutes to cure. Cerium carbonate is not absorbed by the skin, but when dispersed in water in small concentrations, it acts as a self-renewing antioxidant that helps to destroy the harmful ROS chemicals produced by the UV nail gel lamps.
Two years ago, he and Paul Wagner, Katz's former graduate school lab colleague and a successful entrepreneur, founded Magan Material Sciences, Inc. to commercialize Magan's HandShield, a milky liquid that coats the skin without any residue and readily washes off after gel nails are cured.
The mineral spray is a clinically tested, patented water-based formulation that consists of two natural minerals: zinc oxide and a powerful mineral-based antioxidant. The natural mineral formulation helps protect skin and nails from the harm caused by LED nail gel curing lamps by eliminating most of the damaging ROS produced by UVA on the skin.
"What you really care about is decreasing the reactive oxygen species, which are initiators for premature skin aging and skin cancer," Katz said. "The cerium carbonate, which is our discovery and invention, destroys reactive oxygen species made by the UV light emitted by the lamps."
Diego Nicolas Moran for UC Berkeley
Numerous studies have highlighted the potential danger of LED lamps used to harden gel nails, but a 2023 study catapulted the danger into the public eye. It documented DNA damage and mutations in human skin cells caused by ROS produced by LED UV nail polish dryers. Dermatologists started recommending that people lather up with sunscreen beforehand. But that requires removing all sunscreen residue from the nails before applying the gel, since the UV blockers in sunscreen also interfere with the hardening of the nail gel.
Gloves with the fingertips cut out are an alternative, though they leave the skin around the nails and cuticles exposed and unprotected. They're also inconvenient and don't work for toes during a pedicure. One survey found that only 2% of those getting gel nail manicures currently use protection.
"Magan's HandShield is easy to use and economical," Katz said. "For about 5% or less of the cost of a typical manicure you can be protected."
Katz hopes that nail technicians will use the spray for their clients, providing a convenient, hygienic option for helping protect skin.
Prominent dermatologists have already endorsed the product, including the former president of the American Academy of Dermatology, Dr. Seemal Desai, and Dr. Lawrence Eichenfield, professor and vice chair of clinical dermatology at UC San Diego.
How it all started
Katz specializes in catalysis - the study of compounds, often metals, that lower the barrier for chemical reactions to occur, making them take place faster without consuming the catalyst. When the chemical company Dow approached him about eight years ago to find solutions for decreasing oxidative sun damage, which leads to chalking in paints and coatings, he started his investigation with known antioxidants, including cerium compounds.
Diego Nicolas Moran for UC Berkeley
Among these were cerium dioxide, a yellowish mineral that is used to extend the life of some colors of paint, but also cerium nitrate, used for more than 50 years on burns to destroy the ROS molecules that hinder healing. Katz's lab developed a synthesis of cerium carbonate - the precursor to making cerium dioxide - and demonstrated that it was an even more effective antioxidant than anything used before. It was also white and insoluble in water.
Katz and postdoctoral fellow Manish Mishra, co-inventor of the compound, published their findings in 2021, showing how their cerium carbonate particles quench reactive oxygen species that are created by sunlight and drive harmful side reactions that lead to deterioration. Their data demonstrated that cerium carbonate degrades ROS without itself being consumed in the process, meaning it functions as a catalytic antioxidant. The mineral is an effective antioxidant in small quantities - a milligram of insoluble cerium carbonate dispersed in 100 grams of water was sufficient to protect against degradation by ROS.
Katz, Mishra, UC Berkeley and Dow filed for several patents, with the latest patent being granted in 2025. Dow has licensed the patents for use of cerium carbonate in paints and coatings, while Katz and Wagner licensed the patent for human applications.
The founders named the spray after the female name "Magan" - of Greek and Welsh origins and a variant of Margaret - referring to "pearl" and symbolizing purity, wisdom and beauty, in reference to the milky natural mineral dispersion.
The public concern about gel nails, which was amplified by the 2023 paper on the dangers of LED lamps, led Katz to satisfying a societal need.
"The question in my mind was, 'What can we do to make the world a better place by helping people through innovation as opposed to just having another me too?'" Katz said. "It's a special feeling for a professor to have the opportunity to impact something directly in society at large. All through technology developed here at Berkeley."
