[Code of Federal Regulations]
[Title 21, Volume 3]
[Revised as of April 1, 2004]
From the U.S. Government Printing Office via GPO Access
[CITE: 21CFR184.1165]

[Page 489-490]
 
                        TITLE 21--FOOD AND DRUGS
 
CHAPTER I--FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN 
                          SERVICES (CONTINUED)
 
PART 184_DIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS 
SAFE--Table of Contents
 
        Subpart B_Listing of Specific Substances Affirmed as GRAS
 
Sec. 184.1165  n-Butane and iso-butane.

    (a) n-Butane and iso-butane (empirical formula 
C4H10, CAS Reg. Nos. 106-

[[Page 490]]

97-8 and 75-28-5, respectively) are colorless, odorless, flammable gases 
at normal temperatures and pressures. They are easily liquefied under 
pressure at room temperature and are stored and shipped in the liquid 
state. The butanes are obtained from natural gas by fractionation 
following absorption in oil, adsorption to surface-active agents, or 
refrigeration.
    (b) The Food and Drug Administration is developing food-grade 
specifications for n-butane and iso-butane in cooperation with the 
National Academy of Sciences. In the interim, the ingredients must be of 
a purity suitable for their intended use.
    (c) In accordance with Sec. 184.1(b)(1), these ingredients are used 
in food with no limitations other than current good manufacturing 
practice. The affirmation of these ingredients as generally recognized 
as safe (GRAS) as direct human food ingredients is based upon the 
following current good manufacturing practice conditions of use:
    (1) The ingredients are used as propellants, aerating agents, and 
gases as defined in Sec. 170.3(o)(25) of this chapter.
    (2) The ingredients are used in food at levels not to exceed current 
good manufacturing practice.
    (d) Prior sanctions for these ingredients different from the uses 
established in this section do not exist or have been waived.

[48 FR 57270, Dec. 29, 1983]