[Code of Federal Regulations] [Title 21, Volume 3] [Revised as of January 1, 2007] From the U.S. Government Printing Office via GPO Access [CITE: 21CFR179.39] [Page 454-455] TITLE 21--FOOD AND DRUGS CHAPTER I--FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) PART 179_IRRADIATION IN THE PRODUCTION, PROCESSING AND HANDLING OF Subpart B_Radiation and Radiation Sources Sec. 179.39 Ultraviolet radiation for the processing and treatment of food. Ultraviolet radiation for the processing and treatment of food may be safely used under the following conditions: (a) The radiation sources consist of low pressure mercury lamps emitting 90 percent of the emission at a wavelength of 253.7 nanometers (2,537 Angstroms). [[Page 455]] (b) The ultraviolet radiation is used or intended for use as follows: ---------------------------------------------------------------------------------------------------------------- Irradiated food Limitations Use ---------------------------------------------------------------------------------------------------------------- Food and food products................... Without ozone production: high fat- Surface microorganism content food irradiated in vacuum or in control. an inert atmosphere; intensity of radiation, 1 W (of 2,537 A. radiation) per 5 to 10 ft.\2\. Potable water............................ Without ozone production; coefficient of Sterilization of water used absorption, 0.19 per cm or less; flow in food production. rate, 100 gal/h per watt of 2,537 A. radiation; water depth, 1 cm or less; lamp-operating temperature, 36 to 46 [deg]C.. Juice products........................... Turbulent flow through tubes with a Reduction of human minimum Reynolds number of 2,200.. pathogens and other microorganisms. ---------------------------------------------------------------------------------------------------------------- [42 FR 14635, Mar. 15, 1977, as amended at 65 FR 71057, Nov. 29, 2000]