sentences:  Volatile elements must not be allowed to escape during processing.Lamp manufacturers have changed compositions of phosphors to eliminate some toxic elements, such as beryllium, cadmium, or thallium, formerly used.The commonly quoted parameters for phosphors are the wavelength of emission maximum (in nanometers, or alternatively color temperature in kelvins for white blends), the peak width (in nanometers at 50% of intensity), and decay time (in seconds).