Abstract: A method and apparatus for disinfection/pasteurization of fluids. There is provided a mercury/gallium metal halide ultraviolet lamp enclosed within an ozone free metallic doped quartz envelope, an ozone free, metallic doped quartz enclosure for the lamp, an in-line stationary spiral or internal thread of single or multiple leads surrounding the enclosure, and a containment vessel having an inlet, an outlet and a chamber in fluid communication therewith defining a flow path for fluid to be disinfected/pasteurized. The lamp is operated at a wavelength range from about 100 nanometers to about 400 nanometers to introduce multiband ultraviolet radiation and minimal heat into the fluid with the enclosure preventing build up of ozone.