Sunscreen is a chemical protection while sunblock is a physical protection. Sunblock physically blocks ultraviolet (UV) rays while sunscreen absorbs the rays.Know More
Sunscreens and sunblocks are important in protecting the skin from harmful UVA and UVB rays. The SPF, or sun protection factor, denotes how effective a cream is at absorbing UV rays.
Sunblocks are always a thick, opaque cream containing ingredients such as titanium dioxide and zinc oxide. The physical protection blocks forms of UV rays including UVA and UVB. Sunblocks are often cosmetically unappealing as they are visible, difficult to wash off and messy. Sunblocks are recommended for people with an unusual sensitivity to UV rays. Sunblocks cannot be quantified by SPFs as they reflect the rays rather than absorbing them. The SPF of a sunblock is greater than 30.
Sunscreen is a cream which forms a thin, colorless film on the skin that acts as a filter against UV rays. Ingredients in a sunscreen filter reduce and absorb harmful UVA and UVB rays.
Both creams should be applied 30 minutes before sun exposure to ensure protection. Sunscreen or sunblock should be used if exposed to sunlight for longer than 20 minutes.Learn more about Tanning
According to Mayo Clinic, sunblock does have an expiration date, and it is usually found somewhere on the bottle. Not all sunblock has an expiration date listed, but typically it is still acceptable to use it three years after first usage.Full Answer >
Some of the brands, as of 2015, that make sunblock that doesn't contain oxybenzone include Badger, Purple Prairie, Soléo Organics, UV Natural and California Baby. Other brands of sunscreen that don't contain oxybenzone are Little Forest, Vanicream, All Terrain, Carribean Solutions and Estion.Full Answer >
According to the Skin Cancer Foundation, although some approach total protection, no sunscreen is capable of blocking 100 percent of ultraviolet radiation. A sunscreen with a sun protection factor rating, or SPF, of 50 filters out 98 percent of all incoming UV rays.Full Answer >
Higher SPF ratings generally mean better protection from the sun's ultraviolet B rays, so SPF 30 sunscreens provide protection from 97 percent of UVB rays and SPF 45 or higher sunscreens block 98 percent. The SPF rating, however, does not signify how much protection someone gets from ultraviolet A rays, which are also linked to skin cancer, according to the Skin Cancer Foundation.Full Answer >