The label will recommend against wearing the wristband too tightly. It will also include information about the risk of nickel allergies and skin rashes.
The Consumer Products Safety Commission (CPSC) concluded an investigation of skin allergies associated with the Fitbit Flex, but did not ask for a recall.
In February, Fitbit recalled a similar product called the Fitbit Force. The Force was one of the hottest-selling items during last year’s holiday season. In February 2014, over one million of the wristbands were recalled after 10,000 people reported skin irritations, serious blisters, and rashes.
Fitbit has not told users exactly what is causing their skin reactions. However, some consumers without nickel allergies reported developing rashes.
Fitbit Contains Methacrylates
Fitbit recently admitted that the wristbands contain “very small levels of methacrylates,” a common chemical used in plastics and adhesives.
According to warnings (PDF) from the California Department of Public Health, methyl methacrylates (MMA) are a hazardous chemical that can cause skin reactions:
“Direct contact with liquid MMA can cause itching, burning, redness, swelling, and cracking of the skin. Repeated skin contact can cause dermatitis (skin rash). In some people, an allergic skin reaction can occur. There are reports that prolonged skin contact may cause tingling, numbness, and whitening of the fingers. MMA easily penetrates most ordinary clothing and can also penetrate surgical gloves.”