b. Alcohols. Neither ethyl alcohol nor isopropyl alcohol is sporicidal. They
evaporate too quickly for 10-minute coverage, corrode rubber and plastic, and diminish
in effectiveness when exposed to saliva and blood. Alcohols currently have no practical
use in dentistry except as cleansers.
c. Quaternary Ammonium Compounds. Quaternary ammonium compounds
are inactivated by organic matter, are not sporicidal or tuberculocidal, and do not
inactivate hepatitis viruses or gram-negative microbes. Currently, none are accepted
for dental use.
d. Phenols. Simple phenols are not effective for disinfection because they are
not bactericidal or sporicidal.
2-20. CHEMICAL AGENTS COMMONLY USED FOR DISINFECTION
a. General. The chemical agents described below are recommended for use as
chemical disinfectants. For a summary of the information presented below, see figure
b. Iodophors. Iodine compounds usually combine iodine (1 percent) with a
surface-active agent (detergent). They are widely used for surface disinfection.
Iodophors are not caustic to body tissues; however, rare instances of local sensitivity
(allergy) may occur. Dilution and contact time are critical. They are less corrosive than
c. Glutaraldehyde. Glutaraldehyde is the only chemical that kills spores and
can be used for chemical sterilizing from a practical viewpoint. (Others that kill spores
are too corrosive.) Sterility (unmonitored) is attained after immersion in full strength
glutaraldehyde for 10 hours. Glutaraldehyde solution is particularly useful for the
chemical disinfection of rubber and plastic items or items with adhesive bonded parts,
such as certain mirrors that cannot be heated. Several types of glutaraldehyde
solutions are available for use in the dental clinic and each must be mixed according to
manufacturer's instructions. The solutions are active only for a limited time and storage
temperature must be controlled at 80F (26C) or below. When glutaraldehyde is used
for disinfection, the item being disinfected is immersed in the solution. Since the
solution is irritating to the skin, objects being disinfected should be rinsed with 80 to 90
percent alcohol or sterile water before use. Glutaraldehyde should not be used as a
surface disinfectant because of the toxic effects of the fumes.
d. Chlorine Compounds. Chlorine solutions must be replaced on a daily basis.
(1) Sodium hypochlorite. Sodium hypochlorite solution is a disinfectant with
a concentration of 0.5 to 5 percent of chlorine that can be used to disinfect plastic items.
It is corrosive to instruments and can harm skin, eyes, and clothing. While it can be
used for sterilizing or disinfection, sodium hypochlorite is too corrosive to be practical.