Code of Federal Regulations Title 21. Food and Drugs § 21.573.640 Methyl esters of higher fatty acids

(i) Unsaponifiable matter shall be determined by the method described in Section 28.081, “Unsaponifiable Residue (20)—Official Final Action” of the “Official Methods of Analysis of the Association of Official Analytical Chemists,” 13th Ed., 1980, p. 451, which is incorporated by reference. Copies are available from the AOAC INTERNATIONAL, 481 North Frederick Ave., suite 500, Gaithersburg, MD 20877, or available for inspection 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_lo cations.html.

(ii) The chick-edema factor bioassay method described under “26. Oils, Fats, and Waxes” in the Journal of the Association of Official Agricultural Chemists, Vol. 44, Page 146 (1961), or the method described under “Chick–Edema Factor—Bioassay Method (34)—Official Final Action” in §§ 28.113–28.117, “Official Methods of Analysis of the Association of Official Analytical Chemists,” 12th Ed., 1975, pp. 509–511, which is incorporated by reference, shall be employed. (Copies of the methods are available from the AOAC INTERNATIONAL, 481 North Frederick Ave., suite 500, Gaithersburg, MD 20877, or available for inspection 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_lo cations.html.) The presence of chick-edema factor shall be determined by a comparison between the mean log of the pericardial fluid volumes of a test group and of a concurrent negative control group. The significance of the difference in pericardial fluid volumes between the test group and the negative control group is determined by calculating a “t” value according to the formula:

t=	X̄t - X̄c)/square root ((st2/nt)+(sc2/nc))

where:

X̄_t and X̄_c are the means of the logs of the pericardial fluid volumes of the test and control groups, respectively;

n_t and n_c are the number of chicks in the respective groups;

s_t² and s_c² are the variances of the test and control groups, respectively.

The variances are calculated as follows:

s2=	(n(Σx2)-(Σx)2)/(n(n-1))

where:

Σ X is the sum of the logs of the pericardial fluid volumes;

Σ X² is the sum of the squares of the logs of the pericardial fluid volumes for either the test t or control c group data.

The test sample is judged to contain chick-edema factor if the calculated “t” exceeds +1.3 and the mean log of the pericardial fluid volume obtained from the negative control group multiplied by 100 is less than 1.1461.

(iii) “Other factors toxic to chicks” referred to in paragraph (b)(3) of this section shall be determined during the course of the bioassay test described in paragraph (b)(4)(ii) of this section, on the basis of chick deaths or other abnormalities not attributable to chick-edema factor or to the experimental conditions of the test.

(i) The name of the additive.

(ii) The designation “feed grade” in juxtaposition with the name and equally as prominent.