... Silicon Dioxide>99.995%Transmittance of visible light>90% a ) except the incorporation of impurity content of trace titanium, aluminium, iron ... magnesium, potassium, sodium, lithium seven impurity elements of the total content of not greater than 100 x ppm.( two ) ... sterilizing device7. technical datasilicon dioxide>99.95%transmittance of visible light>90%,OH content less than 50ppm,20ppm,15ppm,10ppm ...