Buffers are usually of three types: Acidic buffers: They consist of a weak acid and its salt of a strong base. Th â¦ ey keep the pH constant in the acidic range.Basic buffers: They consist of a weak base and its salt of a strong acid.
I always go with SPF 50+. But, to be honest, there is not *that* much difference on a daily basis from SPF 25 to SPF 50: To figure out your level of protection, divide 1 by the SPF number.That equals the percentage of rays that are allowed to pass through. So SPF 25: 1/25 = 4% of rays pass through.SPF 50 = 1/50 = 2% of rays pass through. always go with SPF 50+. But, to be honest, there is not *that* much difference on a daily basis from SPF 25 to SPF 50: To figure out your level of protection, divide 1 by the SPF number.
For instance, someone using a sunscreen with an SPF of 15 will take 15 times longer to redden than without the sunscreen. An SPF 15 sunscreen screens 93 percent of the sun's UVB rays; SPF 30 protects against 97 percent; and SPF 50, 98 percent.