Light Color Temperature Flourescent lamps are assigned a color temperature based on their coolness or warmness. The human eye perceives colors as cool if they are at the blue-green end of the spectrum. 3500 K is considered neutral white. The lower wattage T8 lamps are not compatible with conventional magnetic ballasts. When upgrading to T8 lamps, electronic ballasts must also be installed.
Electronic ballasts are high-frequency versions of standard magnetic core and coil ballasts.
Other advantages over magnetic ballasts are less humming noise, virtually no flicker, and the capability of operating up to four lamps with one ballast. Advantages T8 lamps can readily replace existing T12 lamps. Ballasts manufactured through 1979 and those without a No PCBs label should be assumed to contain PCBs. Large quantities of ballasts must be disposed of at hazardous waste incinerators or chemical waste landfills. T12 lamps are treated as hazardous material due to their mercury content.