where Eλ is the relative erythemal spectral effectiveness, Sλ is the solar spectral irradiance, Tλ is the average spectral transmission of the specimen, and Δλ is the measured wavelength interval (nm). Antibacterial activity of the fabrics was studied through AATCC 100-2004 (antibacterial finishes on textile materials: assessment of). Escherichia coli (E. coli, ATCC 1399, Gram-negative bacterium) and Staphylococcus aureus (S. aureus, ATCC 1431, Gram-positive bacterium) were used as model challenge microorganisms. The samples were tested in two cultured bacteria based on the McFarland standard, 1 × 10−3 CFU/mL (0.5 McFarland). The fabric samples were immersed in one mL of an appropriate dilution in a bacterium test tube (according to the McFarland standard). The test tubes contained fabric sample and bacteria solution were transferred to an incubator with a temperature of 37 °C for 24 h. The tubes were then removed from the incubator and the solution was dripped onto a plate to assess antibacterial properties. From each test tube, 0.1 mL of bacterial suspension mixed with trypticase soy agar (45 °C) and placed in the incubator at 37 °C for 24 h. After incubation, bacterial colonies were counted. The reduction percent of bacteria was calculated by the equation