Skin cancer — specifically melanoma of the skin — is the most prevalent form of cancer in the U.S., according to the Centers for Disease Control and Prevention (CDC). Citing the most recent annual statistics, the CDC reports 76,665 people in the U.S. were diagnosed with melanomas of the skin in 2014, and 9,324 people died from melanomas that same year. We’ve written about wearables that detect and alert users to excess ultraviolet (UV) light exposure before. LaRoche-Posay‘s My UV Patch,  promises to change color to alert the wearer of dangerous UV levels, while an accompanying app will take into account the user’s skin and current location to recommend a sunscreen product from the company’s catalog. Researchers at the  University of Southern California’s Viterbi School of Engineering developed a patch that changes color with UV exposure and accounts for sunscreen applications.

San Francisco-based LogicInk‘s patent-pending LogicInk UV temporary tattoos are designed to detect and alert wearers of both current UV levels and cumulative exposure. The tattoos work via programmable chemistry, according to the company. There are two designs, LogicInk UV – Circular and LogicInk UV – Bars., with more designs planned. With the circular tattoo, an inner circle changes color from white to purple instantly with increased UV levels. The outer ring displays cumulative exposure with sequential color changes clockwise on the ring. The bar design shows cumulative exposure on an upper bar and current ultraviolet light level on the lower of two bars.

The chemical process that occurs on the tattoos reportedly accounts for skin type and sunscreen applications, although the specific details on how LogicInk UV works are not published or otherwise public at this time. The only specifics available state the tattoo color change reactions are based on the minimal erythemal dose (MED) determined by research as safe (or not) for various skin tones. The product has not come to market yet, but interested parties can sign up for notification when the tattoos are available for sale.