Asked by: Vincent Bradley, Canterbury

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Ordinary glass absorbs 97 per cent of the UVB rays that cause sunburn and some skin cancers, and 37 per cent of the less harmful UVA radiation. This translates to a protection of about SPF30, so you can still get burned with long enough exposure. Car windscreens have a plastic layer bonded between two layers of glass and this blocks all the UVB and 80 per cent of the UVA, making sunburn very unlikely.

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luis villazon
Luis VillazonQ&A expert

Luis trained as a zoologist, but now works as a science and technology educator. In his spare time he builds 3D-printed robots, in the hope that he will be spared when the revolution inevitably comes.

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