CORRELATION OF SUN PROTECTION FACTOR OF SUNSCREEN WITH ABSORBANCE AND TRANSMITTANCE IN THE ULTRAVIOLET RANGE OF RADIATION

Introduction: Ultraviolet solar radiation (UV) is harmful to people both because of sunburn and because of much more serious health problems, among which skin cancer is one of the most serious consequences of exposure to UVA and UVB radiation. Sunscreens protect the skin from harmful solar radiation,by absorbing or blocking UV radiation. The aim of the paper is to determine the correlation between the sun protection factor (SPF) and the absorbance of UV radiation of a domestic brand of sunscreen, and to compare the effectiveness of the domestic brand of sunscreen with other commercially available brands. Method: The UV-Vis spectrophotometric method was used to determine the correlation of the sun protection factor (SPF) with the absorbance and transmittance of UVA and UVB radiation. Results: The results showed a very good correlation and linear dependence of SPF with absorbance in the UVA (R2= 0.993) and in the UVB area (R2= 0.998).A statistically significant difference (P < 0.0001) was observed in the absorbance of UVA and UVB radiation of different brands of sun protection creams with the same protection factor. Conclusion: This study shows a direct correlation between SPF sunscreen and absorbance, which assesses the effectiveness of sunscreens in blocking UVA and UVB radiation. However, it is important to point out that all the researched creams, although they block different amounts of UV radiation, all absorb both UVA and UVB rays. Keywords: Ultraviolet radiation, sun protection factor, absorbance, transmittance