[Title 32 CFR E]
[Code of Federal Regulations (annual edition) - July 1, 2002 Edition]
[Title 32 - NATIONAL DEFENSE]
[Chapter V - DEPARTMENT OF THE ARMY]
[Subchapter H - SUPPLIES AND EQUIPMENT]
[Part 627 - THE BIOLOGICAL DEFENSE SAFETY PROGRAM, TECHNICAL SAFETY REQUIREMENTS (DA PAMPHLET 385-69)]
[Subpart E - Decontamination and Disposal]
[From the U.S. Government Printing Office]
32NATIONAL DEFENSE32002-07-012002-07-01falseDecontamination and DisposalESubpart ENATIONAL DEFENSEDEPARTMENT OF THE ARMYSUPPLIES AND EQUIPMENTTHE BIOLOGICAL DEFENSE SAFETY PROGRAM, TECHNICAL SAFETY REQUIREMENTS (DA PAMPHLET 385-69)
Subpart E--Decontamination and Disposal
Sec. 627.32 Introduction.
All material or equipment that is potentially contaminated with
etiologic agents must be rendered nonhazardous before disposal. This
chapter describes the acceptable physical and chemical decontamination
methods and the general applicability of each. In general, all
infectious materials and all contaminated equipment or apparatus will be
sterilized before being washed and stored or discarded.
Sec. 627.33 Methods of decontamination.
(a) Autoclave. The use of wet heat is the most dependable procedure
for destroying all forms of microbial life. An autoclave employs
saturated steam under a pressure of approximately 15
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pounds per square inch (psi) to achieve a chamber temperature of at
least 121 deg.C for a minimum of 15 minutes. The time is measured after
the temperature of the material being sterilized reaches 121 deg.C.
Other combinations of temperature and pressure (some of which are
dependent on the equipment used) can be used to accomplish sterilization
provided that the efficacy of sterilization is validated as described
below. The most critical factor in ensuring the reliability of this
sterilization method, other than proper temperature, is preventing
entrapped air that is not replaced by stem. Material to be autoclaved
must come in contact with steam and heat and, as a result, it may be
necessary to add water to a load of waste to aid in the formation and
penetration of steam. Autoclaves use either a steam-activated exhaust
valve that reamins open during the replacement of air by live steam
until the steam triggers the valve to close, or a pre-cycle vacuum to
remove air prior to steam introduction.
(b) Sterilization will be verified using biological indicators (for
example, Bacillus stearothermophilus spores) at locations throughout the
autocalve, to include placement in the center of test loads, when the
autoclave is first put into service, and after any maintenance or
repairs. The primary means of verifying routine sterilization will be
through using chemical indicators (for example, autoclave tape or
labels) at locations throughout the autoclave. In addition each
autoclave will be equipped with a permanent means to record time and the
temperature of each operational event as a means of ensuring
sterilization. The type of materials being handled must be reviewed and
standard conditions for sterilization of each established. As a guide,
the manufacturer's manual for the autoclaves will be consulted as a
starting point in establishing these conditions. Treatment conditions to
achieve sterility will vary in relation to the volume of material
treated, the contamination level, the moisture content, and other
factors that should be considered and which may cause the times to
lengthen. In each case, the conditions will be established based on
tests which verify that the conditions selected are effective. In
addition to being effective from viable agents, autoclaving effectively
inactivates most protein toxins.
(c) Dry heat. Dry heat requires longer times or higher temperatures
or both than does wet heat. If used, the specific sterilization times
and temperatures must be determined for each type of material being
sterilized. In general, sterilization by dry heat can be accomplished at
169-170 deg.C for periods of 2 to 4 hours. Higher temperatures reduce
the time requirements. The heat transfer properties and spatial relation
or arrangement of materials in the load are critical in ensuring
effective sterilization.
(d) Liquid disinfectants. Liquid disinfectants may be used in
surface treatment, in dip tanks, and, at sufficient concentration, as
sterilants of liquid waste for final disposal. If liquid disinfectants
are used, they must have been shown to be effective against the
organisms present. Important considerations include: temperature, time
of contact, the negative logarithm of hydrogen ion concentration (pH),
concentration and state of dispersion, penetrability, and reactivity of
organic material at the site of application. Small variations in these
factors may make large differences in the effectiveness of disinfection,
so complete reliance should not be placed on liquid disinfectants when
the end result must be sterility. If evidence of efficacy under the
proposed procedures has not been reported previously, preliminary
studies to verify the efficacy of liquid disinfectants must be
conducted. Such studies may include attempts to recover and quantitate
the agent in question from liquid or swab samples, or sealed patches, by
animal inoculation, plaque assay, agar or broth cultivation, and similar
methods, following controlled decontamination under the same
experimental conditions envisioned for the proposed studies.
(1) Alcohol. Ethyl or isopropyl alcohol at the concentration of 70-
85 percent by weight will denature proteins but is slow in its
germicidal action. Alcohols are effective disinfectants for lipid-
containing viruses. These alcohols exhibit no activity against bacterial
spores.
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(2) Phenolic compounds. These are effective disinfectants against
vegetative bacteria, including Mycobacterium tuberculosis, fungi, and
lipid-containing viruses. The phenolics are not effective against
bacterial spores or non-lipid-containing viruses. The concentrations
used will be in accordance with the manufacturer's recommendations.
(3) Formaldehyde solutions. Formaldehyde in solution at a
concentration of 8 percent (formalin) is effective against vegetative
bacteria, spores, and viruses. It loses considerable disinfectant
activity below room temperature. Due to the toxic properties of
formaldehyde, the use of formalin is restricted to surfaces or materials
that are contained within appropriate engineering controls.
(4) Quaternary ammonium compounds. These cationic detergents are
strongly surface-active. They lose effectiveness in the presence of
proteins and are neutralized by anionic detergents, such as soap. At low
concentrations, they are bacteriostatic, tuberculostatic, sporostatic,
fungistatic, and algistatic. At medium concentration, they are
bactericidal, fungicidal, algicidal, and virucidal against lipophilic
viruses. They are not tuberculocidal, sporicidal, or virucidal against
hydrophilic viruses, even at high concentrations. The manufacturer's
recommended dilution will be used.
(5) Chlorine. Sodium hypochlorite is normally used as a base for
chlorine disinfectants. Free available chlorine is the active ingredient
and, at concentrations of at least 2,500 parts per million (ppm) (0.25
percent), is a disinfectant that is active against most microorganisms
and bacterial spores. Chlorine solutions at 2.5 percent free available
chlorine are effective against most toxins. Chlorine solutions lose
strength if exposed to air, so fresh solutions must be prepared whenever
the free chlorine content falls below desired minimums.
(6) Iodine. The characteristics of chlorine and iodine are similar.
Iodophor compounds with 1,600 ppm free available iodine provide a
relatively rapid inactivation of all microorganisms, including some
bacterial spores. A commonly available iodophor is Wescodyne. The
manufacturer of Wescodyne recommends a range of dilution form 1 to 3
ounces per 5 gallons of water, giving a solution containing from 25 to
75 ppm of free iodine. At these concentrations, available iodine may be
rapidly taken up by any extraneous protein present and will not be an
effective sporocide. A solution providing 1,600 ppm iodine is
recommended for hand washing or for use as a sporocide.
(7) Mercurials. Although the mercurials exhibit good activity
against viruses, they are toxic and are not recommended for general use.
They have poor activity against vegetative bacteria and are totally
ineffective sporicides. The dilution recommendations stated by the
manufacturer will be followed.
(e) Vapors and gases. Formaldehyde, ethylene oxide, peracetic acid,
beta-propiolactone, methyl bromide, and glutaraldehyde have all been
used successfully as space sterilants where they can be employed in
closed systems and with controlled conditions of temperature and
humidity. Of these, methyl bromide, beta-propiolactone, and
glutaraldehyde are not recommended because of their toxic properties.
Peracetic acid can readily decompose with explosive violence in a
concentrated state and must be used only in a diluted state and with
extreme care. Formaldehyde and ethylene oxide are both regulated by OSHA
for their potential human carcinogenicity, but do have permissible
exposure levels (unlike beta-propiolactone, for example) and can be used
safely under controlled conditions.
(1) Formaldehyde. Formaldehyde gas is, in general, the chemical of
choice for space disinfection. Biological safety cabinets and associated
effluent air-handling systems and air filters, incubators, laboratory
rooms, buildings, or other enclosed spaces can be disinfected with
formaldehyde. The procedures found in appendix E of the National
Sanitation Foundation Standard Number 49 will be followed for the
disinfection of biological safety cabinets. Other enclosures or areas
will be disinfected by following the same principles. To disinfect
rooms, the generation of formaldehyde gas from heating powdered or flake
paraformaldehyde is
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the preferred method. When area decontamination is performed, use 0.3
grams of paraformaldehyde for each cubic foot of space to be treated.
The room or area must be above 70 deg.F, the relative humidity above 70
percent, and the exposure time at least 2 hours (overnight is
preferred). After the required time for disinfection, the room must be
cleared of the formaldehyde gas (a small room with nonporous surfaces
and no materials or equipment in the room can be cleared of all
detectable formaldehyde by aeration for one hour, while larger areas
with equipment in them may take a full day). Before formaldehyde is used
as a space disinfectant, the area to be treated must be surveyed to
ensure that there are no open containers of any acidic solution
containing chloride ion in order to prevent the possible formation of
bis (chloromethyl)ether, a human carcinogen. Specific OSHA requirements
for posting of rooms and equipment, personnel protection, and other
requirements are found in 29 CFR 1910.1048.
(2) Ethylene oxide (EtO). EtO sterilization will only be conducted
in a sterilizer designed for that purpose and designed to maintain
potential exposure levels below the current OSHA standard. EtO is
effective against all microorganisms, including spores, molds,
pathogenic fungi, and highly resistant thermophilic bacteria. All
materials to be used in contact with human skin (for example, clothing,
shoes, masks, adhesive tape) must be aerated for at least 24 hours after
sterilization and prior to use. Concentrations of 500 to 1000 ppm are
required for sterilization. Specific OSHA requirements for the use of
ethylene oxide are found in 29 CFR 1910.1047.
(f) UV Radiation. UV radiation at a wave length of 253.7 nanometers
is a practical method for inactivating airborne virsuses, mycoplasma,
bacteria, and fungi. The usefulness of UV radiation on exposed surfaces
is limited by its low penetrating power. UV radiation shall only be
relied upon to sterilize surfaces when conventional methods, such as
autoclaving or the use of liquid disinfectants, would make the product
unusable. An example is data sheets that must be brought out of a
biocontainment facility. The UV intensity must be at least 40
microwatts/cm 3 on the surface to be treated. Single sheets
of paper may be treated by exposing them to this radiation for a minimum
of 15 minutes. A calibrated photoelectric UV intensity meter, capable of
measuring UV radiation at a wave length of 253.7 nanometers, will be
used whenever a new UV source is installed, and quarterly thereafter, to
ensure the UV source is providing at least 40 microwatts/cm 3
at the work surface. Bulbs should be cleaned routinely to remove any
accumulated dust and prolong bulb performance and assure proper energy
output. Protective eye wear and clothing may be necessary when working
around UV radiation.
Sec. 627.34 Disposal.
Inactivation is the first step in the disposal of etiologic agents
or materials that are potentially contaminated with them. All
contaminated or potentially contaminated materials must be effectively
disinfected or sterilized by an approved procedure discussed in
Sec. 627.33. After decontamination, reusable items, such as clothing or
glassware, may be washed with other uncontaminated or decontaminated
items.
(a) Combustible items. Combustible disposable items should be bagged
and incinerated in an appropriate approved incinerator or otherwise
disposed of in accordance with State and local regulations.
(b) Noncombustible disposable items. Items will be packaged as
stated in Sec. 626.34(e) and disposed of by a licensed waste hauler.
(c) Equipment. Equipment that cannot be autoclaved will be
decontaminated by gaseous sterilization or with a suitable liquid
disinfectant. Such equipment will be certified as decontaminated by the
safety officer.
(d) Waste. Materials generated, such as solvents, acids, chemical
carcinogens, radioactive isotopes, medical waste, or dead animals must
be decontaminated, packaged, and then disposed of in accordance with
EPA, NRC, local, State, and Federal regulations.
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(e) Mixed waste. When two or more hazardous materials are mixed
together, the mixture will be decontaminated and disposed of in
accordance with EPA, NRC, State, and Federal regulations for the
mixture, or for the most hazardous material.
(f) Packaging. Solid waste will be placed in cans, sturdy bags, or
boxes. Rigid, puncture-resistant, sealable containers will be used for
packaging ``sharps.'' When wet materials are packaged for disposal, the
materials will be placed in a leak-proof container. Heavy waste will be
placed in rigid containers ensuring that the burst strength of the
container is not exceeded.
(g) Labeling. A method of verifying that all items prepared for
disposal have been decontaminated will be established for etiologic
agent wastes. Mixed waste will be labeled as appropriate to indicate the
hazards that must be addressed after decontamination.
(h) Recordkeeping. A manifest will be initiated and maintained,
where required, to record the disposition and transfer of waste.
Applicable Federal, State, and local ordnances will be followed.