Final answer:
A good sunscreen has an SPF of 30 or higher and offers protection against both UVA and UVB rays. Ingredients like Padimate O, avobenzone, titanium dioxide, and zinc oxide provide broad-spectrum coverage. Sun protective clothing can also offer additional defense against UV radiation.
Step-by-step explanation:
What Makes a Good Sunscreen?
When selecting a good sunscreen, it's essential to choose one with a sun protection factor (SPF) of 30 or higher to effectively shield against the damaging effects of solar radiation. While an SPF value of 30 can filter out 97% of UVB rays, higher SPF levels provide marginally increased protection. A sunscreen that protects against both UVA and UVB radiation is recommended, with active ingredients such as Padimate O, avobenzone, titanium dioxide, or zinc oxide for broad-spectrum coverage.
In addition to the chemical protection sunscreens provide, physical protection is also available through sun protective clothing with a UPF rating. Overexposure to UV radiation can lead to skin damage and skin cancer, making effective sunscreens and protective measures crucial. Sunscreen ingredients play different roles; some may absorb UV radiation, while others like zinc oxide and titanium dioxide may both absorb and scatter it, providing a comprehensive defense against UVA and UVB radiation.