Third-party testing organization NSF International is shifting rules and regulations governing portions of the standard microbiological water treatment technologies. NSF 55, which was once a technology-based standard for ultraviolet (UV) technologies, is becoming an all-microbial standard that will cover UV distillation, halogenation, filtration and ozonation. The halogenation and ozone inclusions are new. The halogenation standards will include chlorine, bromine and iodine among other elements. The new standard, when formally approved later this year, is expected to take effect in 2002.