21 CFR 864.6550 - Occult blood test.
(a) Identification. An occult blood test is a device used to detect occult blood in urine or feces. (Occult blood is blood present in such small quantities that it can be detected only by chemical tests of suspected material, or by microscopic or spectroscopic examination.)
[45 FR 60606, Sept. 12, 1980]
Title 21 published on 2013-04-01
no entries appear in the Federal Register after this date.