The suitability of SunCheck® patches and Tanscan® cards for monitoring the sunburning effectiveness of sunlight

UV‐sensitive products which undergo a colour change on exposure to UV radiation are available for use by the general public. We have evaluated SunCheck® patches of various sensitivities, and Tanscan® UV sensor cards, in terms of their temperature stability, wavelength response and response to sunlight. The products exhibited no perceptible colour change when the temperature was maintained at 45°C for 4 hours; on exposure to monochromatic radiation, the sensitivity peaked at a wavelength of 335 and 355 nm for SunCheck® and Tanscan®, respectively; the response to sunlight under clear conditions was reasonably consistent, with the coefficient of variation for each type of material ranging between 12.5 and 27%. These products are based on the incorrect concept that there is a ‘safe’ dose of UV radiation. Thus, they cannot be recommended to the public as a reliable way of reducing the risk of skin cancer.