While J. Kiernan is correct that 2 hr. in aqueous 4% formaldehyde kills MOST
bacteria, some very nasty ones survive this treatment.  A fair percentage of
mycobacteria (TUBERCULOSIS, LEPROSY, CROHN'S DISEASE) survive.  While active
ANTHRAX and bacteria are killed, many of the spores survive.

Allen A. Smith, Ph.D.
School of Graduate Medical Sciences
   Podiatric Medicine and Surgery
Barry University
Miami Shores, Florida