People need to be educated about the application of sunscreens, say specialists from the Royal Liverpool university hospital in a letter to the British Medical Journal (2000;320:1275). Dr Richard Azurdia (specialist registrar in dermatology) and Dr Lesley Rhodes (consultant dermatologist) write that, in an assessment of sunscreen application, they found the overall thickness applied was 0.5mg/cm2 with some sites missed completely. Following patient education about application technique, the thickness of sunscreen application rose to 1mg/cm2.
They comment that this level is still half the standard thickness used in testing sun protection factors and suggest that 1mg/cm2 might be more appropriate for tests.