Sun Protection
Factor (SPF)
The SPF of a sunscreen is a laboratory
measure of the effectiveness of sunscreen; the higher the
SPF, the more protection a sunscreen offers against UV-B
(the ultraviolet radiation that causes sunburn). The SPF
indicates the time a person can be exposed to sunlight
before getting sunburn with a sunscreen applied relative to
the time they can be exposed without sunscreen. For example,
someone who would burn after 12 minutes in the sun would
expect to burn after 2 hours (120 min) if protected by a
sunscreen with SPF 10.
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