7 CFR § 91.26 - Issuance of certificates.
(a) The person signing and issuing the certificate of analysis shall be one of the following:
(1) The scientist who performed the analysis;
(2) Another technician of the laboratory facility, who has been given power of attorney by the scientist who performed the analytical testing and been authorized by the Deputy Administrator to affix the scientist's signature to a certificate. The power of attorney shall be on file with the employing office or laboratory of the Science and Technology program;
(3) A person designated as the “laboratory director in charge,” when the certificate represents composite analyses by several technicians.
(b) The laboratory certificate shall be prepared in accordance with the facts set forth in the official memoranda made by the scientist or technicians in connection with the analysis.
(c) Whenever a certificate is signed by a person under a power of attorney, the certificate should so indicate. The signature of the holder of power shall appear under the name of the scientist who personally analyzed the sample, and whenever a certificate issued is signed by a scientist in charge, that title must appear in connection with the signature.