CFR > Title 21 - Food and Drugs > CHAPTER I—FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES > SUBCHAPTER B—FOOD FOR HUMAN CONSUMPTION (parts 100 to 191) > PART 179—IRRADIATION IN THE PRODUCTION, PROCESSING AND HANDLING OF FOOD > SUBPART B—Radiation and Radiation Sources (§179.21 to §179.41) > 179.39—Ultraviolet radiation for the processing and treatment of food.

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).
(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-content food irradiated in vacuum or in an inert atmosphere; intensity of radiation, 1 W (of 2,537 A. radiation) per 5 to 10 ft.2 Surface microorganism control.
Potable water Without ozone production; coefficient of absorption, 0.19 per cm or less; flow rate, 100 gal/h per watt of 2,537 A. radiation; water depth, 1 cm or less; lamp-operating temperature, 36 to 46 °C. Sterilization of water used in food production.
Juice products Turbulent flow through tubes with a minimum Reynolds number of 2,200. Reduction of human pathogens and other microorganisms.

Code of Federal Regulations

[42 FR 14635, Mar. 15, 1977, as amended at 65 FR 71057, Nov. 29, 2000]