Shat-R-Shield shatterproof / shatter-resistant T8 fluorescent lamps are coated from end-to-end with the patented, plastic safety coating. The coating reduces light output by only less than 1% and is a minimum of 16 mils thick. Antioxidants and ultraviolet stabilizers are present in most coatings to block UV emissions from 180 - 390 nanometers. If used properly under warranty criteria, the coating is guaranteed not to yellow, crack or flake for the rated-life of the lamp.