With the number of sunscreens available it is difficult to work out which one is the best. According to her there are two basic types of sun protection creams — physical and chemical sun blocks. Physical sun blocks use either zinc or titanium oxide to reflect or scatter the UVA and UVB rays from the sun. However they may block our skin pores causing small papules to form. Chemical sun blocks contain several ingredients that absorb mainly UVB and seine UVA rays and prevent damage to the skin.
Another factor to study while buying a sunscreen lotion is the SPF written on the side of the bottle. The SPF or Sun Protection Factor is calculated by comparing the amount of time needed to produce sunburn on a protected skin to the amount of time needed to cause sunburn on unprotected skin. For e.g. a person who turns red after 10 minutes in the sun takes 20 minutes to turn red after using a sunscreen with SPF 2 and 150 minutes after applying a cream with SPF 15. Another thing to keep in mind while purchasing a sunscreen is what percentage of protection is ensured with a particular SPF. Some Doctor / Skin Expert recommend a SPF 30 screen for children as it blocks 97 per cent of UV rays but do keep in mind that a minimal SPF of 15 screens 93 per cent of UV rays.
You have chosen a sunscreen with a SPF of 30 and it is probably a mix of physical and chemical types. Now check if the label also carries the words broad spectrum and waterproof. Next, make sure your child is not allergic to the sunscreen you have selected by applying it to a small area and waiting for 24 hours for any reactions.