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Sunscreens have become very popular and of the wide range in the market, it is difficult to choose. Can you give some basic information to help us make an informed choice? What is the significance of SPF? SPF is an abbreviation for the ‘Sun Protection Factor’ in the sunscreen and usually denotes the protection that a sunscreen gives from ultraviolet B rays. While SPF 15, for example, blocks 93 per cent of ultraviolet B rays, SPF 30 blocks 97 per cent. After that, the increase in SPF does not offer any significant advantage. A good sunscreen should be capable of shielding your skin from the effects of both ultraviolet B and ultraviolet A rays. While UVA is responsible for premature skin ageing (compared to Caucasians, we have a much lower risk), UVB exposure leads to darkening and thickening of the outer cell layers. While the tan produced by UVA disappears quickly, the one produced by UVB lasts a relatively long time. Internationally, SPF values denote the level of protection against UVB rays but there is no such common international indicator for UVA. So different countries have adopted different methods of expressing it. In the United States, the term ‘broad spectrum’ represents protection against both UVA and B. Only those sunscreens that offer UVA protection proportional to UVB and pass the FDA’s tests formulated for the purpose are allowed to use the term on the label. In Japan, on the other hand, a four-level Protection Grade of UVA system, expressed as ‘PA’ (based on the ‘Persistent Pigment Darkening’ method) is used to denote the level of safeguards offered by sunscreens against UVA. Thus PA+, PA++, PA+++ and PA ++++ are indicative of the degrees of protection. In India, you find some sunscreen labels indicating that they offer protection against both UVA and UVB, while some only mention the SPF factor. Some of them also use the term‘broad spectrum,’ while yet others indicate the SPF and the PA values. So in the absence of any uniform labelling norms, it is not easy to compare products, but do make sure that the sunscreen that you choose offers protection against both UVA and UVB. Are sunscreens made of natural products better? Products made of natural ingredients are certainly better, provided the claim (about its contents) is true and the product is stable and capable of giving protection against both UVB and UVA. It is also important to follow manufacturers’ instructions about usage.
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While SPF 50 offers 98 per cent protection from UVB rays, SPF 100 is said to give 99 per cent protection. The Food and Drug Administration in the United States says that there is no sufficient data to show that products with SPF values higher than 50 provide greater protection than products with SPF values of 50. It does not make sense to pay more for higher SPF values. In Australia, the labelling regulations for sunscreen prohibit manufacturers from mentioning a value higher than SPF 30. Anything beyond it can only be described as SPF 30+. This is to ensure that consumers do not unnecessarily pay for higher SPF in the belief that it is offering them better protection. 