§175.250 石蜡(合成品)(Paraffin （synthetic）)

　　§ 175.250   Paraffin （synthetic）.

　　Synthetic paraffin may be safely used as an impregnant in, coating on, or component of coatings on articles used in producing, manufacturing, packing, processing, preparing, treating, packaging, transporting, or holding food in accordance with the following prescribed conditions:

　　（a） The additive is synthesized by the Fischer-Tropsch process from carbon monoxide and hydrogen, which are catalytically converted to a mixture of paraffin hydrocarbons. Lower molecular-weight fractions are removed by distillation. The residue is hydrogenated and may be further treated by percolation through activated charcoal. This mixture can be fractionated into its components by a solvent separation method, using synthetic isoparaffinic petroleum hydrocarbons complying with §178.3530 of this chapter.

　　（b） Synthetic paraffin shall conform to the following specifications:

　　（1） Congealing point. There is no specification for the congealing point of synthetic paraffin components, except those components that have a congealing point below 50 °C when used in contact with food Types III, IVA, V, VIIA, and IX identified in table 1 of §176.170（c） of this chapter and under conditions of use E, F, and G described in table 2 of §176.170（c） of this chapter shall be limited to a concentration not exceeding 15 percent by weight of the finished coating. The congealing point shall be determined by ASTM method D938–71 （Reapproved 1981）, “Standard Test Method for Congealing Point of Petroleum Waxes, Including Petrolatum,” which is incorporated by reference. Copies may be obtained from the American Society for Testing Materials, 100 Barr Harbor Dr., West Conshohocken, Philadelphia, PA 19428-2959, or may be examined at the National Archives and Records Administration （NARA）. For information on the availability of this material at NARA, call 202–741–6030, or go to: http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.

　　（2） Oil content. The substance has an oil content not exceeding 2.5 percent as determined by ASTM method D721–56T, “Tentative Method of Test for Oil Content of Petroleum Waxes” （Revised 1956）, which is incorporated by reference. See paragraph （b）（1） of this section for availability of the incorporation by reference.

　　（3） Absorptivity. The substance has an absorptivity at 290 millimicrons in decahydronaphthalene at 88 °C not exceeding 0.01 as determined by ASTM method E131–81a, “Standard Definitions of Terms and Symbols Relating to Molecular-Spectroscopy,” which is incorporated by reference. See paragraph （b）（1） of this section for availability of the incorporation by reference.

　　（c） The provisions of this section are not applicable to synthetic paraffin used in food-packaging adhesives complying with §175.105.

　　[42 FR 14534, Mar. 15, 1977, as amended at 47 FR 11839, Mar. 19, 1982; 49 FR 10106, Mar. 19, 1984; 51 FR 47010, Dec. 30, 1986; 60 FR 39645, Aug. 3, 1995]