UV Index: How to use it!
As described in other sections of the UV
information, the UV Index is a forecast of the probable intensity of skin damaging
ultraviolet radiation reaching the surface during the solar noon hour (11:30-12:30 local
standard time or 12:30-13:30 local daylight time). The greater the UV Index is the greater
the amount of skin damaging UV radiation. How much UV radiation is needed to actually
damage one's skin is dependant on several factors. But in general the darker one's skin
is, (that is the more melanin one has in his/her skin) the longer (or the more UV
radiation) it takes to cause erythema (skin reddening).
Figure 1
shows a look up chart where by one can cross check his/her propensity to burn versus
the UV Index. For those who always burn and never tan the times to burn are relatively
short compared to those who almost always tan.
The EPA has devised general guidelines as far as what to do to protect oneself
from overexposure to UV radiation. These are shown in the table below.
Exposure Category |
UV Index |
Protective Actions |
Minimal |
0, 1, 2 |
Apply skin protection factor (SPF) 15 sun screen. |
Low |
3, 4 |
SPF 15 & protective clothing (hat) |
Moderate |
5, 6 |
SPF 15, protective clothing, and UV-A&B sun glasses. |
High |
7, 8, 9 |
SPF 15, protective clothing, sun glasses and make attempts to
avoid the sun between 10am to 4pm. |
Very High |
10+ |
SPF 15, protective clothing, sun glasses and avoid being in the
sun between 10am to 4pm. |
|