Inactivation of Bacillus anthracis spores. (Synopsis).After the intentional release of Bacillus anthracis Bacillus anthracis Infectious disease A gram-positive organism which causes often fatal infections when its endospores–resistant to heat, drying, UV light, gamma radiation, and many disinfectants–enter the body and cause septicemia Military medicine through the U.S. Postal Service The U.S. Postal Service (USPS) processes and delivers mail to individuals and businesses within the United States. The service seeks to improve its performance through the development of efficient mail-handling systems and operates its own planning and engineering programs. in the fall of 2001, many environments were contaminated contaminated, v 1. made radioactive by the addition of small quantities of radioactive material. 2. made contaminated by adding infective or radiographic materials. 3. an infective surface or object. with B. anthracis spores, and frequent inquiries were made regarding the science of destroying these spores. We conducted a survey of the literature that had potential application to the inactivation inactivation /in·ac·ti·va·tion/ (in-ak?ti-va´shun) the destruction of biological activity, as of a virus, by the action of heat or other agent. of B. anthracis spores. This article provides a tabular summary of the results. ********** In October 2001, several letters containing Bacillus anthracis spores were sent through the U.S. Postal Service to recipients in government and private-sector buildings. Consequently, 23 human inhalational or cutaneous anthrax Noun 1. cutaneous anthrax - a form of anthrax infection that begins as papule that becomes a vesicle and breaks with a discharge of toxins; symptoms of septicemia are severe with vomiting and high fever and profuse sweating; the infection is often fatal infections occurred. Five of the 11 inhalational anthrax anthrax (ăn`thrăks), acute infectious disease of animals that can be secondarily transmitted to humans. It is caused by a bacterium (Bacillus anthracis infections were fatal (1,2). As a result of this intentional release of B. anthracis, several post offices, mailrooms in government buildings, and private office buildings were contaminated with B. anthracis spores. During the initial response, frequent requests were made for published materials about inactivating Bacillus bacillus (bəsĭl`əs), any rod-shaped bacterium or, more particularly, a rod-shaped bacterium of the genus Bacillus. Some bacterium in the genus cause disease, for example B. spores. However, no adequate single source of literature on this subject was available. Because of the risk to humans, remediation of anthrax-contaminated buildings and their contents has been the focus both of scientific discussion and commercial product marketing. A number of manufacturers have developed equipment or materials that reportedly kill B. anthracis spores. However, these manufacturers have tested their products with laboratory tests that use Bacillus species other than B. anthracis, and the efficacy of some of these technologies relies on published literature. An obvious concern is whether postremediation levels of spores are safe; the summarized studies make no claim about whether a safe level exists and what it might be. We provide a summary of much of the available literature on the inactivation of Bacillus spores that is relevant to the inactivation of B. anthracis. We reviewed publications from 1930 to 2002, and we have created a tabular summary of those articles. Treatments or agents commonly cited include heat, formaldehyde formaldehyde (fôrmăl`dəhīd'), HCHO, the simplest aldehyde. It melts at −92°C;, boils at −21°C;, and is soluble in water, alcohol, and ether; at STP, it is a flammable, poisonous, colorless gas with a suffocating , hypochlorite hypochlorite /hy·po·chlo·rite/ (-klor´it) any salt of hypochlorous acid; used as a medicinal agent with disinfectant action, particularly as a diluted solution of sodium hypochlorite. solutions, chlorine dioxide chlorine dioxide, n an oxidizing agent used in oral care to decrease amounts of volatile sulfur compounds that may cause halitosis. , and radiation. Methods regarding inoculum inoculum /in·oc·u·lum/ (-ok´u-lum) pl. inoc´ula material used in inoculation. in·oc·u·lum n. pl. size, concentration, and other variables are not consistent between experiments, but each experiment provides some specific information of value. Early studies that lack quantitative data are not included. A number of the cited studies address Bacillus species other than B. anthracis. We include these for information, with the caveat that surrogates do not always predict the behavior of the target species. Furthermore, the results from laboratory experiments do not specifically address questions regarding the best methods for inactivating spores on different materials such as mail, carpet, other porous objects, food, or water. Transfer of these sporicidal methods from the laboratory to a building has not yet been tested; however, the known laboratory results are a logical place to start when considering the decontamination decontamination /de·con·tam·i·na·tion/ (de?kon-tam-i-na´shun) the freeing of a person or object of some contaminating substance, e.g., war gas, radioactive material, etc. de·con·tam·i·na·tion n. of a building. Decontamination is defined as the irreversible inactivation of infectious agents infectious agent Pathogen, see there so that an area is rendered safe. However, decontamination may not eliminate bacterial spores bacterial spore, n a bacteria that, because of its thick outer wall, is easily able to survive in hostile environments otherwise not conducive to bacterial growth and reproduction. . Sterilization sterilization Any surgical procedure intended to end fertility permanently (see contraception). Such operations remove or interrupt the anatomical pathways through which the cells involved in fertilization travel (see reproductive system). is the complete destruction or elimination of microbial microbial pertaining to or emanating from a microbe. microbial digestion the breakdown of organic material, especially feedstuffs, by microbial organisms. viability, including spores (3). The experiments described provide a logical starting point Noun 1. starting point - earliest limiting point terminus a quo commencement, get-go, offset, outset, showtime, starting time, beginning, start, kickoff, first - the time at which something is supposed to begin; "they got an early start"; "she knew from the for future experiments and decontamination strategies in the event of anthrax bioterrorism. Our intent is not to provide a comparative evaluation or recommendations for decontamination but rather to summarize the quantitative published results and provide a useful reference. Review Variations in time, temperature, concentration, pH, and relative humidity relative humidity n. The ratio of the amount of water vapor in the air at a specific temperature to the maximum amount that the air could hold at that temperature, expressed as a percentage. may affect the sporicidal activity of various agents. Accordingly, and especially for real-world situations, attention must be paid simultaneously to more than one controllable or uncontrollable factor. In Tables 1 and 2 and in the discussion, we address some of the key ancillary factors. Boiling water for > 10 minutes, for example, can reduce B. anthracis spore counts by at least 106 (Table 1). Variations in time and temperature conditions required to reduce spore counts listed in Table 1 can be attributed to differences in experimental conditions, strains of B. anthracis tested, or inoculum size. The U.S. Environmental Protection Agency Environmental Protection Agency (EPA), independent agency of the U.S. government, with headquarters in Washington, D.C. It was established in 1970 to reduce and control air and water pollution, noise pollution, and radiation and to ensure the safe handling and indicates that use of sodium hypochlorite sodium hypochlorite n. An unstable salt usually stored in solution and used as a fungicide and an oxidizing bleach. as a sporicide sporicide /spo·ri·cide/ (spor´i-sid) an agent that destroys spores.sporici´dal spo·ri·cide n. An agent that kills spores. is applicable under an emergency exemption (Section 18: Crisis Exemption; Federal Insecticide, Fungicide, and Rodenticide Act The Federal Insecticide, Fungicide, and Rodenticide Act (or FIFRA), 7 U.S.C. 136 et seq. is a United States federal law that set up the basic US system of pesticide regulation to protect applicators, consumers and the environment. ); as such, sodium hypochlorite may be used under the conditions specified (32). Given these conditions, the sporicidal effectiveness of hypochlorite solutions depends on the concentration of free available chlorine and pH. Common household bleach (sodium hypochlorite) has a pH of 12 to prolong its shelf life. To achieve effective sporicidal activity, bleach must be diluted with water to increase the free available chlorine and acetic acid acetic acid (əsē`tĭk), CH3CO2H, colorless liquid that has a characteristic pungent odor, boils at 118°C;, and is miscible with water in all proportions; it is a weak organic carboxylic acid (see carboxyl group). to change the pH of the solution to 7 (11). Organic matter may decrease the sporicidal efficiency of sodium hypochlorite (33). Concentration, humidity, temperature, and carrier material affect gaseous gas·e·ous adj. 1. Of, relating to, or existing as a gas. 2. Full of or containing gas; gassy. sterilization of spores. Ethylene oxide ethylene oxide Occupational medicine A gas used to sterilize medical supplies and other materials penetrates into porous material (absorbed strongly by rubber and many plastics); thus vapors are not readily eliminated by brief aeration aeration /aer·a·tion/ (ar-a´shun) 1. the exchange of carbon dioxide for oxygen by the blood in the lungs. 2. the charging of a liquid with air or gas. aer·a·tion n. . Ethylene oxide is also flammable flam·ma·ble adj. Easily ignited and capable of burning rapidly; inflammable. [From Latin flamm (34). Residual spores were not completely killed after a 30-minute exposure to chlorine dioxide at a relative humidity of 20% to 40%, whereas all spores were killed after a 15-minute exposure to chlorine dioxide with the addition of prehumidification at a relative humidity of 70% to 75% (21). Peracetic acid peracetic acid a potent disinfectant used as a 3% concentration; suitable for the destruction of anthrax spores. vapor does not penetrate well into porous surfaces and is flammable. The amount of contamination, level of cleanliness of surfaces, and relative humidity will contribute to peracetic acid vapor's effectiveness as a sporicide (24). Organic matter may absorb and chemically react with propylene oxide propylene oxide a gas used to disinfect animal feeds. , reducing its effectiveness. Organic matter may also provide physical protection from the oxide (25). The sporicidal property of ozone is affected by relative humidity: as relative humidity decreases, the time required for killing organisms increases (27). Discussion Decontamination of buildings from intentional release of B. anthracis is a new problem, and no accumulated scientific knowledge exists on the subject. Two areas of prior scientific research may be relevant: food processing Food processing is the set of methods and techniques used to transform raw ingredients into food for consumption by humans or animals. The food processing industry utilises these processes. and laboratory decontamination. With modification based on further study, the technologies used in laboratories and food processing plants may be applied to buildings. Direct information on killing B. anthracis spores in foods by cooking is scarce, and the complexity of food matrices precludes easy extrapolation (mathematics, algorithm) extrapolation - A mathematical procedure which estimates values of a function for certain desired inputs given values for known inputs. If the desired input is outside the range of the known values this is called extrapolation, if it is inside then of the laboratory data into nonfood non·food adj. Of, relating to, or being something that is not food but is sold in a supermarket, as housewares or stationery. matrices. However, information on inactivating spores of bacterial species more resistant to environmental conditions than B. anthracis can provide guidance. The spores of Clostridium botulinum Clostridium bot·u·li·num n. A bacterium that occurs widely in nature and is a cause of botulism; its six main types, A to F, are characterized by antigenically distinct but pharmacologically similar, very potent neurotoxins. are more resistant to heat inactivation than are B. anthracis spores (4). The commercial retort re·tort n. A closed laboratory vessel with an outlet tube, used for distillation, sublimation, or decomposition by heat. retort a globular, long-necked vessel used in distillation. process of canning achieves a 12-log reduction of C. botulinum bot·u·li·num or bot·u·li·nus n. An anaerobic, rod-shaped bacterium (Clostridium botulinum) that secretes botulin and inhabits soils. spores, and by extension, should achieve a similar killing rate for B. anthracis spores. Further research in this area is needed. Historically, formaldehyde solution or gas has been used both as a disinfectant disinfectant, agent that destroys disease-causing microorganisms and their spores. Disinfectants, or germicides, are sometimes considered to be substances applied to inanimate bodies, whereas antiseptics, not so potent, are agents that kill microbes on living things. and chemical sterilant sterilant a sterilizing agent, i.e. an agent that destroys microorganisms. . Formaldehyde was used to disinfect To remove the virus code that has attached itself to a legitimate file. Sometimes, the antivirus program cannot untangle the code, and the infected file has to be deleted. See quarantine. as early as the late 1880s and is still used to reprocess re·proc·ess tr.v. re·proc·essed, re·proc·ess·ing, re·proc·ess·es To cause to undergo special or additional processing before reuse. Verb 1. hemodialyzers for reuse on the same patient and to decontaminate de·con·tam·i·nate tr.v. de·con·tam·i·nat·ed, de·con·tam·i·nat·ing, de·con·tam·i·nates 1. To eliminate contamination in. 2. biologic safety cabinets and laboratories (35-37). Formaldehyde gas has been used for fumigation fumigation: see disinfectant. in the poultry industry and for disinfection disinfection, n the process of destroying pathogenic organisms or rendering them inert. disinfection, full oral cavity, n a procedure used to reduce active periodontal disease, usually completed within a certain short time frame. of biologic safety cabinets and laboratories (38,39). Data from controlled experiments with B. globigii NCTC NCTC National Conservation Training Center NCTC National Counterterrorism Center (9/11 Commission Report) NCTC National Cable Television Cooperative NCTC National Collection of Type Cultures (UK laboratory) 10073 spores have demonstrated the effect of humidity on formaldehyde concentration (mg/[m.sup.3]) to obtain a >8-log reduction in viable spores (15). Fumigation with formaldehyde vapor (18 mg/L-21 mg/L) has also been used to treat a textile mill contaminated with B. anthracis spores (40). In this instance, contamination was greatly reduced immediately after treatment and was undetectable 6 months later. However, the possible role of formaldehyde as a carcinogen carcinogen: see cancer. carcinogen Agent that can cause cancer. Exposure to one or more carcinogens, including certain chemicals, radiation, and certain viruses, can initiate cancer under conditions not completely understood. has limited its use. Formaldehyde can be neutralized neu·tral·ize tr.v. neu·tral·ized, neu·tral·iz·ing, neu·tral·iz·es 1. To make neutral. 2. To counterbalance or counteract the effect of; render ineffective. 3. with ammonium bicarbonate ammonium bicarbonate n. A white crystalline salt, bicarbonate of ammonium, NH4HCO3, used in fire-extinguishing compounds and in baking powder. after fumigation, reducing its carcinogenic carcinogenic having a capacity for carcinogenesis. properties. Gamma radiation gamma radiation, high-energy photons emitted as one of the three types of radiation resulting from natural radioactivity. It is the most energetic form of electromagnetic radiation, with a very short wavelength (high frequency). was used in the 1960s and 1970s to disinfect B. anthracis--contaminated imported bailed goat hair. A study by Home et al. suggested that a dose of 1.5 megarads from a 200,000-rad/hour cobalt source was sufficient to kill most resistant spores when mixed with goat hair; 2 megarads was recommended to include a margin of safety (31). After the intentional release of B. anthracis through the postal system postal system System that allows persons to send letters, parcels, or packages to addressees in the same country or abroad. Postal systems are usually government-run and paid for by a combination of user charges and government subsidies. in 2001, pursuing a decontamination method for the undelivered undelivered adj → no entregado al destinatario; if undelivered return to sender → en caso de no llegar a su destino devolver al, remitente undelivered mail was essential. Gamma radiation was used to decontaminate all mail from contaminated facilities on the basis of these data. Summary Multiple technologies may be needed to decontaminate buildings and their contents. As in a laboratory, where some items are wiped, some items are autoclaved, and some spaces are treated with gas, more than one method may be required for decontamination. Also, for certain decontamination tasks, e.g., cleaning small heat-proof and water-proof objects, more than one option will be available. Further, even within the context of one type of application (e.g., walls; ducts for heating, ventilating ventilating Natural or mechanically induced movement of fresh air into or through an enclosed space. The hazards of poor ventilation were not clearly understood until the early 20th century. Expired air may be laden with odors, heat, gases, or dust. , air conditioning air conditioning, mechanical process for controlling the humidity, temperature, cleanliness, and circulation of air in buildings and rooms. Indoor air is conditioned and regulated to maintain the temperature-humidity ratio that is most comfortable and healthful. , and refrigeration refrigeration, process for drawing heat from substances to lower their temperature, often for purposes of preservation. Refrigeration in its modern, portable form also depends on insulating materials that are thin yet effective. ; carpet; and small objects), potentially conflicting priorities exist between bioefficacy, logistics, and safety. Our review suggests two conclusions. First, additional scientific research is needed. Although transferring the methods used to decontaminate or sterilize sterilize /ster·i·lize/ (ster´i-liz) 1. to render sterile; to free from microorganisms. 2. to render incapable of reproduction. ster·il·ize v. 1. laboratory or food industry settings to decontaminating buildings may be useful, this transfer of methods has not been scientifically tested. Also, much of the data available is based on other Bacillus species; more testing with or correlation to B. anthracis contamination is suggested. Second, choosing between technologies is a complex issue, and a formal decision process would be useful. Various parties in the public and private sector have suggested numerous, sometimes disparate, methods for the inactivation of B. anthracis spores in contaminated environments. Further research is needed regarding improved methods for remediation of environments contaminated with B. anthracis spores, and the literature summarized here provides a basis for that effort.
Table 1. Heat inactivation of Bacillus anthracis spores
Temperature Time Inoculum size
Boiling
100[degrees]C 10 min 3 x [10.sup.6]
5 min 7.5 x [10.sup.8]
Moist heat
90[degrees]C 20 min 1.2 x [10.sup.6]
90[degrees]C to
91[degrees]C 60 min 3 x [10.sup.8]
100[degrees]C 10 min 1.2 x [10.sup.6]
100[degrees]C to
101[degrees]C 17 min 1 x [10.sup.5]
105[degrees]C 10 min 3 x [10.sup.6]
120[degrees]C 15 min 2.4 x [10.sup.8]
Dry heat
140[degrees]C >90 min 6 x [10.sup.3] to 1.2 x [10.sup.4]
150[degrees]C 10 min 6 x [10.sup.3] to 1.2 x [10.sup.4]
160[degrees]C 10 min 6 x [10.sup.3] to 1.2 x [10.sup.4]
180[degrees]C 2 min 6 x [10.sup.3] to 1.2 x [10.sup.4]
190[degrees]C 1 min 6 x [10.sup.3] to 1.2 x [10.sup.4]
200[degrees]C 30 sec 6 x [10.sup.3] to 1.2 x [10.sup.4]
Temperature Inactivation effect Ref.
Boiling
100[degrees]C Sample sterilized 4,5
Sample sterilized
Moist heat
90[degrees]C Sample sterilized 4,5
90[degrees]C to
91[degrees]C Spores detected
100[degrees]C Sample sterilized 5,6
100[degrees]C to
101[degrees]C Sample sterilized
105[degrees]C Sample sterilized 5
120[degrees]C Sample sterilized 4
Dry heat
140[degrees]C Sample sterilized 7
150[degrees]C Sample sterilized
160[degrees]C Sample sterilized
180[degrees]C Sample sterilized
190[degrees]C Sample sterilized
200[degrees]C Sample sterilized
(a) Spores in liquid suspension exposed to flowing steam
at 100 [degrees] C.
Table 2. Efficiency of chemicals, gases, and radiation on the
inactivation of Bacillus spores
Method Concentration Inoculum size
Chemical sterilization
Calcium 20 ppm available; 3 x [10.sup.5]-4 x
hypochlorite [Cl.sub.2], pH [10.sup.5] spores of
8.0, 20[degrees]C Bacillus subtilis in
5.0 mL sterile distilled
[H.sub.2]O
25 ppm available; 2 x [10.sup.7] spores/mL
[Cl.sup.2], pH of B. metiens in 10 mL of
6.0, 20[degrees]C sterile distilled
[H.sub.2]O
Free available 2.4-2.3 mg/L available; 1.1 x [10.sup.5] spore
chlorine C[L.sub.2], pH 7.2, suspension of B.
22[degrees]C anthracis
Sodium 0.05%, pH 7.0, Spore suspension of B.
hypochlorite 20[degrees]C subtilis globigii,
(NaOCl) 0.05%, pH 11.0, representing 1.6-2.2 x
20[degrees]C [10.sup.9] CFU/mL
Hydrogen 25.8%, 24[degrees]C B. subtilis globigii
peroxide 25.8%, 76[degrees]C spore suspension (no
([H.sub.2] concentration)
[O.sub.2]) 0.88 mol/L, pH 5.0 [10.sup.6] CFU/mL B.
subtilis spore suspension
0.88 mol/L, pH 4.3 10 mL B. subtilis spore
suspension coated onto
stainless steel carders
Peracetic acid 0.13 mol/L, pH 5.0, 6.5, [10.sup.6] CFU/mL B.
(C[H.sub.3] 8.0 subtilis
COOOH) 0.39 mol/L, pH 4.0, 7.0, 10 mL B. subtilis spore
9.0 suspension coated on
stainless steel carriers
Formaldehyde 4% in water [10.sup.8]/mL B.
(C[H.sub.2]O) anthracis
400 mg/[m.sup.3], 30% RH [10.sup.2]-3 x [10.sup.8]
280 mg/[m.sup.3], 50%RH B. globigii NCTC 10073
250 mg/[m.sup.3], 80% RH dried on disks
400 mg/[m.sup.3], 98% RH
Glutaraldehyde 2% in water, pH 8.0 [10.sup.8]/mL spores B.
([C.sub.5] anthracis
[H.sub.8]
[O.sub.2])
Sodium 5%, 27.8[degrees]C 7 x [10.sup.9] spores/mL
hydroxide 5%, 21.l[degrees]C B. subtilis
(NaOH)
Gaseous sterilization
Ethylene oxide Exposed to constant B. globigii and B.
([C.sub.2] boiling HCL at anthracis dried onto
[H.sub.4]O) 20[degrees]C for 30 min suture loop carders (no
before exposure to concentration)
ethylene oxide at room
temperature
500 mg/L, 30%-50% RH, ~[10.sup.6] spores B.
54.4[degrees]C globigii on
nonhygroscopic surfaces
~[10.sup.6] spores B.
globigii on hygroscopic
surfaces
Chlorine 40 mg/L, 60%-80% RH, 1.4 x [10.sup.6]/0.2 mL
dioxide 25[degrees]C- B. subtilis subsp. Niger
(Cl[O.sub.2]) 27[degrees]C dried on paper and
aluminum foil strips
30 mg/L, 80%-85% RH, [10.sup.6] spores/
30[degrees]C biologic indicator; B.
subtilis subsp. Niger
6-7 mg/L, 20%-40% RH, [10.sub.6] spores/
23[degrees]C biologic indicator; B.
subtilis subsp. Niger
70%-75% RH for 0.5
before exposure,
23[degrees]C
Hydrogen 0.208 mg/L, 1.5 Torr 3.4 x [10.sup.5] B.
peroxide pretreatment for 10 min; subtilis subsp. Globgii
([H.sub.2] 2.49 MHz, 150 W of spores on paper disks and
[O.sub.2]) pulsed plasma in a cycle packaged in spun-bonded
plasma of 0.5 ms plasma on, 1.0 polyethylene
ms plasma off
Methylene 3.4-3.9 g/L, room 1 x [10.sup.5]-5 x
bromide temperature in the [10.sup.7] spores of B.
(C[H.sub.3]Br) presence of moisture anthracis dried on
sterile filter paper
strips
Peracetic acid 1 mg/L, 80% RH 6 x [10.sup.5] - 8 x
vapor [10.sup.5] B. subtilis
(C[H.sub.3] niger dried on filter-
COOOH) paper disks and glass
squares
1 mg/L, 60% RH
1 mg/L, 40% RH
Propylene 1,250 mg/L, 86% RH, 9.5 x [10.sup.5]-1.1 x
oxide 36[degrees]C- [10.sup.6] spores B.
([C.sub.3] 38[degrees]C subtilis niger dried on
[H.sub.6]O) filter paper
1,000 mg/L, 2.5 x [10.sup.7] spores
37[degrees]C B. subtilis niger in
cereal flakes
Ozone 1.0 mg/L generated in 1.8 x [10.sup.5] spores/
([O.sub.3]) water pH 3 mL B. cerus
3.0 mg/L, [10.sup.8]-2 x [10.sup.8]
preconditioned at 54% B. subtilis dried on
filter paper
RH [10.sup.8]-2 x [10.sup.8]
B. cerus dried on filter
paper
900 ppm, preconditioned 5 x [10.sup.7] spores/
at 65%-70% RH for 15 h glass coupon
Radiation
UV 85% 2537A B. anthracis (mixed
spores and vegetative
forms) in beef extract
agar pH 7.4 (no
concentration)
4,800 [micro]Ws/ 0.1 mL of [10.sup.8] B.
[cm.sup.2] anthracis spore
suspension dried on
aluminum carriers
450,000 [micro]Ws/ 0.1 mL of [10.sup.8] B.
[cm.sup.2] anthracis spore
suspension dried on
ceramic carriers
52.8 x [10.sup.6] 0.1 mL of [10.sup.8] B.
[micro]Ws/[cm.sup.2] anthracis spore
suspension dried on wood
carriers
Gamma [10.sup.6] spores/mL
irradiation B. anthracis
Method Concentration Time
Chemical sterilization
Calcium 20 ppm available; 4.8 min
hypochlorite [Cl.sub.2], pH
8.0, 20[degrees]C
25 ppm available; 2.5 min
[Cl.sup.2], pH
6.0, 20[degrees]C
Free available 2.4-2.3 mg/L available; 1 h
chlorine C[L.sub.2], pH 7.2,
22[degrees]C
Sodium 0.05%, pH 7.0, 30 min
hypochlorite 20[degrees]C
(NaOCl) 0.05%, pH 11.0,
20[degrees]C
Hydrogen 25.8%, 24[degrees]C 15 min
peroxide 25.8%, 76[degrees]C <1 min
([H.sub.2] 0.88 mol/L, pH 5.0 3 h
[O.sub.2]) 0.88 mol/L, pH 4.3 6 h
Peracetic acid 0.13 mol/L, pH 5.0, 6.5, <30 min
(C[H.sub.3] 8.0
COOOH) 0.39 mol/L, pH 4.0, 7.0, 24 h
9.0
Formaldehyde 4% in water 2 h
(C[H.sub.2]O) 400 mg/[m.sup.3], 30% RH 22 min
280 mg/[m.sup.3], 50%RH 31 min
250 mg/[m.sup.3], 80% RH 16 min
400 mg/[m.sup.3], 98% RH 9 min
Glutaraldehyde 2% in water, pH 8.0 15 min
([C.sub.5]
[H.sub.8]
[O.sub.2])
Sodium 5%, 27.8[degrees]C 1.5 h
hydroxide 5%, 21.l[degrees]C 3.6 h
(NaOH)
Gaseous sterilization
Ethylene oxide Exposed to constant 1 h
([C.sub.2] boiling HCL at
[H.sub.4]O) 20[degrees]C for 30 min
before exposure to
ethylene oxide at room
temperature
500 mg/L, 30%-50% RH, 30 min
54.4[degrees]C
Chlorine 40 mg/L, 60%-80% RH, 1 h
dioxide 25[degrees]C-
(Cl[O.sub.2]) 27[degrees]C
30 mg/L, 80%-85% RH, 30 min
30[degrees]C
6-7 mg/L, 20%-40% RH, 30 min
23[degrees]C
70%-75% RH for 0.5 15 min
before exposure,
23[degrees]C
Hydrogen 0.208 mg/L, 1.5 Torr 15 min
peroxide pretreatment for 10 min;
([H.sub.2] 2.49 MHz, 150 W of
[O.sub.2]) pulsed plasma in a cycle
plasma of 0.5 ms plasma on, 1.0
ms plasma off
Methylene 3.4-3.9 g/L, room 24 h
bromide temperature in the
(C[H.sub.3]Br) presence of moisture
Peracetic acid 1 mg/L, 80% RH 10 min
vapor
(C[H.sub.3] 1 mg/L, 60% RH
COOOH)
1 mg/L, 40% RH
Propylene 1,250 mg/L, 86% RH, 1.05 h
oxide 36[degrees]C-
([C.sub.3] 38[degrees]C
[H.sub.6]O)
1,000 mg/L, 3 h
37[degrees]C
Ozone 1.0 mg/L generated in 5 min
([O.sub.3]) water pH 3
3.0 mg/L,
preconditioned at 54% 1.5 h 95%
RH
RH 1.5 h 95%
RH
900 ppm, preconditioned 30 min
at 65%-70% RH for 15 h 80% RH
60 min
70% RH
Radiation
UV 85% 2537A 452
ergs/[mm.sup.2]
4,800 [micro]Ws/ <96 h
[cm.sup.2]
450,000 [micro]Ws/ <96 h
[cm.sup.2]
52.8 x [10.sup.6] 30 h
[micro]Ws/[cm.sup.2]
Gamma Dose of
irradiation 1 x [10.sup.6] rad
Method Concentration Efficiency
Chemical sterilization
Calcium 20 ppm available; 99% killed
hypochlorite [Cl.sub.2], pH
8.0, 20[degrees]C
25 ppm available; 0.061 (log of average %
[Cl.sup.2], pH survivors) 99% killed
6.0, 20[degrees]C
Free available 2.4-2.3 mg/L available; >99.99% killed (1
chlorine C[L.sub.2], pH 7.2, spore/mL survived)
22[degrees]C
Sodium 0.05%, pH 7.0, 99.99% killed
hypochlorite 20[degrees]C 50% spores survived
(NaOCl) 0.05%, pH 11.0,
20[degrees]C
Hydrogen 25.8%, 24[degrees]C 0.001% survived
peroxide 25.8%, 76[degrees]C <0.0001% survived
([H.sub.2] 0.88 mol/L, pH 5.0 100% killed
[O.sub.2]) 0.88 mol/L, pH 4.3 100% killed
Peracetic acid 0.13 mol/L, pH 5.0, 6.5, 100% killed
(C[H.sub.3] 8.0
COOOH) 0.39 mol/L, pH 4.0, 7.0, 100% killed
9.0
Formaldehyde 4% in water [10.sub.4] inactivation
(C[H.sub.2]O) factor
400 mg/[m.sup.3], 30% RH 1 [log.sub.l0] reduction,
280 mg/[m.sup.3], 50%RH at 23.5[degrees]C-
250 mg/[m.sup.3], 80% RH 25[degrees]C
400 mg/[m.sup.3], 98% RH
Glutaraldehyde 2% in water, pH 8.0 [10.sup.4] inactivation
([C.sub.5] factor
[H.sub.8]
[O.sub.2])
Sodium 5%, 27.8[degrees]C 99% killed
hydroxide 5%, 21.l[degrees]C 99% killed
(NaOH)
Gaseous sterilization
Ethylene oxide Exposed to constant 100% killed
([C.sub.2] boiling HCL at
[H.sub.4]O) 20[degrees]C for 30 min
before exposure to
ethylene oxide at room
temperature
500 mg/L, 30%-50% RH, 4-log reduction
54.4[degrees]C
6-log reduction
Chlorine 40 mg/L, 60%-80% RH, 100% killed
dioxide 25[degrees]C-
(Cl[O.sub.2]) 27[degrees]C
30 mg/L, 80%-85% RH, 100% killed (estimated
30[degrees]C time to kill 90%,
4.4 min)
6-7 mg/L, 20%-40% RH, [10.sup.1]CFU/biologic
23[degrees]C indicator (estimated time
to kill 90%, 4.2 min)
70%-75% RH for 0.5 0 CFU/biologic indicator
before exposure, (estimated time to kill
23[degrees]C 90%, 1.6 min)
Hydrogen 0.208 mg/L, 1.5 Torr 100% killed
peroxide pretreatment for 10 min;
([H.sub.2] 2.49 MHz, 150 W of
[O.sub.2]) pulsed plasma in a cycle
plasma of 0.5 ms plasma on, 1.0
ms plasma off
Methylene 3.4-3.9 g/L, room 100% killed
bromide temperature in the
(C[H.sub.3]Br) presence of moisture
Peracetic acid 1 mg/L, 80% RH <1 spore remained on
vapor paper and glass
(C[H.sub.3]
COOOH) 1 mg/L, 60% RH 2 spores remained on
paper; 38 spores
remained on glass
1 mg/L, 40% RH 24 spores remained on
paper; 1,530 spores
remained on glass
Propylene 1,250 mg/L, 86% RH, 90% killed
oxide 36[degrees]C-
([C.sub.3] 38[degrees]C
[H.sub.6]O)
1,000 mg/L, 3.7% survived
37[degrees]C
Ozone 1.0 mg/L generated in <[10.sup.1] CFU/mL
([O.sub.3]) water pH 3 survived
3.0 mg/L, <0.001% survived
preconditioned at 54%
RH <0.001% survived
900 ppm, preconditioned [10.sup.0] survived
at 65%-70% RH for 15 h
[10.sup.0] survived
Radiation
UV 85% 2537A 90% killed
4,800 [micro]Ws/ 2.4 log reduction,
[cm.sup.2] unreliable results
450,000 [micro]Ws/ 2.03 log reduction,
[cm.sup.2] unreliable results
52.8 x [10.sup.6] 0.67 log reduction
[micro]Ws/[cm.sup.2]
Gamma 100% killed
irradiation
Method Concentration Ref
Chemical sterilization
Calcium 20 ppm available; 8
hypochlorite [Cl.sub.2], pH
8.0, 20[degrees]C
25 ppm available; 9
[Cl.sup.2], pH
6.0, 20[degrees]C
Free available 2.4-2.3 mg/L available; 10
chlorine C[L.sub.2], pH 7.2,
22[degrees]C
Sodium 0.05%, pH 7.0, 11
hypochlorite 20[degrees]C
(NaOCl) 0.05%, pH 11.0,
20[degrees]C
Hydrogen 25.8%, 24[degrees]C 12
peroxide 25.8%, 76[degrees]C
([H.sub.2] 0.88 mol/L, pH 5.0 13
[O.sub.2]) 0.88 mol/L, pH 4.3
Peracetic acid 0.13 mol/L, pH 5.0, 6.5, 13
(C[H.sub.3] 8.0
COOOH) 0.39 mol/L, pH 4.0, 7.0,
9.0
Formaldehyde 4% in water 14
(C[H.sub.2]O) 400 mg/[m.sup.3], 30% RH 15
280 mg/[m.sup.3], 50%RH
250 mg/[m.sup.3], 80% RH
400 mg/[m.sup.3], 98% RH
Glutaraldehyde 2% in water, pH 8.0 14
([C.sub.5]
[H.sub.8]
[O.sub.2])
Sodium 5%, 27.8[degrees]C 16
hydroxide 5%, 21.l[degrees]C
(NaOH)
Gaseous sterilization
Ethylene oxide Exposed to constant 17
([C.sub.2] boiling HCL at
[H.sub.4]O) 20[degrees]C for 30 min
before exposure to
ethylene oxide at room
temperature
500 mg/L, 30%-50% RH, 18
54.4[degrees]C
Chlorine 40 mg/L, 60%-80% RH, 19
dioxide 25[degrees]C-
(Cl[O.sub.2]) 27[degrees]C
30 mg/L, 80%-85% RH, 20
30[degrees]C
6-7 mg/L, 20%-40% RH, 21
23[degrees]C
70%-75% RH for 0.5
before exposure,
23[degrees]C
Hydrogen 0.208 mg/L, 1.5 Torr 22
peroxide pretreatment for 10 min;
([H.sub.2] 2.49 MHz, 150 W of
[O.sub.2]) pulsed plasma in a cycle
plasma of 0.5 ms plasma on, 1.0
ms plasma off
Methylene 3.4-3.9 g/L, room 23
bromide temperature in the
(C[H.sub.3]Br) presence of moisture
Peracetic acid 1 mg/L, 80% RH 24
vapor
(C[H.sub.3] 1 mg/L, 60% RH
COOOH)
1 mg/L, 40% RH
Propylene 1,250 mg/L, 86% RH, 25
oxide 36[degrees]C-
([C.sub.3] 38[degrees]C
[H.sub.6]O)
1,000 mg/L,
37[degrees]C
Ozone 1.0 mg/L generated in 26
([O.sub.3]) water pH 3
3.0 mg/L, 27
preconditioned at 54%
RH
900 ppm, preconditioned 28
at 65%-70% RH for 15 h
Radiation
UV 85% 2537A 29
4,800 [micro]Ws/ 30
[cm.sup.2]
450,000 [micro]Ws/
[cm.sup.2]
52.8 x [10.sup.6]
[micro]Ws/[cm.sup.2]
Gamma 31
irradiation
(a) RH, relative humidity; conversions: 1 ppm = 1 mg/L;
mol/L = gram molecular weight/L; 1 rad = 100 ergs/g; and
1 watt = [10.sub.7] ergs/s.
References (1.) Centers for Disease Control and Prevention Centers for Disease Control and Prevention (CDC), agency of the U.S. Public Health Service since 1973, with headquarters in Atlanta; it was established in 1946 as the Communicable Disease Center. . Update: investigation of bioterrorism-related inhalational anthrax--Connecticut, 2001. MMWR MMWR Morbidity & Mortality Weekly Report Epidemiology A news bulletin published by the CDC, which provides epidemiologic data–eg, statistics on the incidence of AIDS, rabies, rubella, STDs and other communicable diseases, causes of mortality–eg, Morb Mortal Wkly Rep 2001;50:1049. (2.) Centers for Disease Control and Prevention. Suspected cutaneous anthrax in a laboratory worker--Texas, 2002. MMWR Morb Mortal Wkly Rep 2002;51:279-80. (3.) Dorland WAN. Dorland's illustrated medical dictionary A medical dictionary is a lexicon for words used in medicine. The three major English language medical dictionaries are Stedman's, Taber's, and Dorland's medical dictionaries. (standard version). In: Dorland WE, editor. 29th ed. Philadelphia: W.B. Saunders & Co; 2000. p. 2088. (4.) Stein CD, Rodgers H. Observations on the resistance of anthrax spores to heat. Veterinary Medicine veterinary medicine, diagnosis and treatment of diseases of animals. An early interest in animal diseases is found in ancient Greek writings on medicine. Veterinary medicine began to achieve the stature of a science with the organization of the first school in the 1945;40:406-10. (5.) Murray TJ. Thermal death point. J Infect Dis 1931;48:457-67. (6.) Schneiter R, Kolb RW. Heat resistance studies with spores of Bacillus anthracis and related aerobic bacilli bacilli /ba·cil·li/ (bah-sil´i) plural of bacillus. bacilli see bacillus. in hair and bristles. Public Health Rep 1945;suppl 207:1-24. (7.) Francis A. Observations on time and temperature in the killing of spores by dry heat. Proceedings of the Pathological Society Aims and Mission The Pathological Society (of Great Britain and Ireland) is a professional organisation whose mission is stated as 'understanding disease' Membership and Profile of Great Britain and Ireland Great Britain and Ireland are the two largest islands in the British Isles. A former state, the United Kingdom of Great Britain and Ireland, was composed of the political union of the two. 1956;71:351-2. (8.) Charlton D, Levine M. Germicidal germicidal /ger·mi·ci·dal/ (jer?mi-si´d'l) antimicrobial (1). germicidal destructive to pathogenic microorganisms. properties of chlorine compounds. Vol. 35. Ames (IA): Iowa State College; 1937. p. 1-60. (9.) Rudolph A, Levine M. Factors affecting the germicidal efficiency of hypochlorite solutions. The Iowa State College Bulletin 1941;XL:1-48. (10.) Brazis A, Leslie J, Kabler P, Woodward R. The inactivation of spores of Bacillus globigii Noun 1. Bacillus globigii - a species of bacillus found in soil and decomposing organic matter; some strains produce antibiotics Bacillus subtilis, grass bacillus, hay bacillus and Bacillus anthracis by free available chlorine. Appl Microbiol 1958;6:338-42. (11.) Sagripanti J, Bonifacino A. Comparative sporicidal effects of liquid chemical agents. Appl Environ Microbiol 1996;62:545-51. (12.) Toledo R, Escher F, Ayres J. Sporicidal properties of hydrogen peroxide hydrogen peroxide, chemical compound, H2O2, a colorless, syrupy liquid that is a strong oxidizing agent and, in water solution, a weak acid. It is miscible with cold water and is soluble in alcohol and ether. against food spoilage spoilage decomposition; said of meat, milk, animal feeds especially ensilage. organisms. Appl Microbiol 1973;26:592-7. (13.) Baldry M. The bactericidal bactericidal /bac·te·ri·ci·dal/ (bak-ter?i-si´d'l) destructive to bacteria. Bactericidal An agent that destroys bacteria (e.g. , fungicidal fun·gi·cide n. A chemical substance that destroys or inhibits the growth of fungi. fun  gi·cid , and sporicidal
properties of hydrogen peroxide and peracetic acid. J Appl Bacteriol
1983;54:417-23.(14.) Rubbo S, Gardner J, Webb R. Biocidal bi·o·cid·al adj. Of or relating to an agent that is destructive to living organisms. biocidal (bī´ōsī´d activities of gluteraldehyde and related compounds. J Appl Bacteriol 1967;30:78-87. (15.) Cross GLC, Lach V. The effects of controlled exposure to formaldehyde vapor on spores of Bacillus globigii NCTC 10073. J Appl Bacteriol 1990;68:461-9. (16.) Whitehouse R, Clegg L. Destruction of Bacillus subtilis Noun 1. Bacillus subtilis - a species of bacillus found in soil and decomposing organic matter; some strains produce antibiotics Bacillus globigii, grass bacillus, hay bacillus spores with solutions of sodium hydroxide sodium hydroxide, chemical compound, NaOH, a white crystalline substance that readily absorbs carbon dioxide and moisture from the air. It is very soluble in water, alcohol, and glycerin. It is a caustic and a strong base (see acids and bases). . J Dairy Res 1963;30:315-22. (17.) Friedl J, Ortenzio L, Stuart L. The sporicidal activity of ethylene oxide as measured by the AOAC AOAC Association of Official Analytical Chemists (now AOAC International) AOAC Association of Analytical Communities AOAC Association of Analytical Chemists AOAC Always On/Always Connected AOAC Aero-Optic Evaluation Center sporicide test. Journal of the Association of Official Agricultural Chemist 1956;39:480-3. (18.) Kereluk K, Gammon R. The microbicidal activity of ethylene oxide. In: Developments in industrial microbiology Industrial microbiology A field concerned with the development of technologies to control and manipulate the growth and activities of selected biological agents to create desirable products and economic gain or to prevent economic loss. . Symposium: recent approaches to sterilization and achievement of sterility 1973;14:28-41. (19.) Knapp J, Rosenblatt D, Rosenblatt A. Chlorine dioxide as a gaseous sterilant. Sterilization Science 1986;8:48-51. (20.) Jeng D, Woodworth A. Chlorine dioxide gas sterilization of oxygenators in an industrial scale sterilizer sterilizer /ster·i·liz·er/ (ster´i-liz?er) an apparatus for the destruction of microorganisms. ster·il·iz·er n. An apparatus for rendering objects aseptic. : a successful model. Artif Organs 1990;14:361-8. (21.) Jeng D, Woodworth A. Chlorine dioxide gas sterilization under square-wave conditions. Appl Environ Microbiol 1990;56:514-9. (22.) Jacobs P, Lin S. Hydrogen peroxide plasma sterilization system. Arlington (TX): Surgikos, Inc.; 1987. p. 13. (23.) Kolb R, Schneiter R. The germicidal and sporicidal efficacy of methyl bromide methyl bromide Toxicology An insecticide and rodenticide, which is a volatile fumigant 3-fold denser than air and absorbed through skin, producing narcosis, pulmonary edema, renal tubule damage, jacksonian convulsions, CNS depression, peripheral neuropathy; for Bacillus anthracis. J Bacteriol 1950;59:401-12. (24.) Portner D, Hoffman R. Sporicidal effect of peracetic acid vapor. Appl Microbiol 1968;16:1782-5. (25.) Bruch C, Koesterer M. The microbicidal activity of gaseous propylene oxide and its application to powdered or flaked foods. Food Research 1960:25;428-35. (26.) Foegeding P, Fulp M. Comparison of coats and surface-dependent properties of Bacillus cereus Bacillus ce·re·us n. A species of Bacillus that causes an emetic type and a diarrheal type of food poisoning in humans. T prepared in two sporulation sporulation /spor·u·la·tion/ (spor?u-la´shun) formation of spores. spor·u·la·tion n. The production or release of spores. sporulation formation of spores or sporozoites. environments. J Appl Bacteriol 1988;65:249-59. (27.) Ishizaki K, Shinriki N, Matsuyama H. Inactivation of Bacillus spores by gaseous ozone. J Appl Bacteriol 1986;60:67-72. (28.) Currier R, Torraco D, Cross J, Wagner G, Gladden glad·den v. glad·dened, glad·den·ing, glad·dens v.tr. To make glad. See Synonyms at please. v.intr. Archaic To be glad. Verb 1. P, Vanderberg L. Deactivation de·ac·ti·vate tr.v. de·ac·ti·vat·ed, de·ac·ti·vat·ing, de·ac·ti·vates 1. To render inactive or ineffective. 2. To inhibit, block, or disrupt the action of (an enzyme or other biological agent). 3. of clumped and dirty spores of Bacillus globigii. Ozone Science and Engineering 2001;23:285-94. (29.) Sharp D. The lethal action of short ultraviolet rays Ultraviolet rays Invisible light rays with a wavelength shorter than that of visible light but longer than that of x rays. Mentioned in: Sunscreens on several common pathogenic bacteria Pathogenic bacteria Bacteria that produce illness. Mentioned in: Gastroenteritis . J Bacteriol 1939;37:447-60. (30.) Dietz P, Bohm R, Strauch D. Investigation on disinfection and sterilization of surfaces by ultraviolet radiation. Zbl Bakt Hyg 1980;171:158-67. (31.) Home T, Turner G, Willis A. Inactivation of spores of Bacillus anthracis by G-radiation. Nature 1959;4659:475-6. (32.) U.S. Environmental Protection Agency. Pesticides: topical and chemical fact sheets. 2003, Feb 19 [cited 2003 March 31]. Available from: URL URL in full Uniform Resource Locator Address of a resource on the Internet. The resource can be any type of file stored on a server, such as a Web page, a text file, a graphics file, or an application program. : http://www.epa.gov/pesticides/factsheets/ chemicals/bleachfactsheet.htm#bkmrk7 (33.) Dychdala G. Chlorine and chlorine compounds. In: Block SS, editor. Disinfection and sterilization and preservation. Philadelphia: Lea and Febiger; 1983. p. 157-82. (34.) Bruch C. Gaseous sterilization. In: Clifton CE, Raffel S, Starr MP, editors. Annu Rev Microbiol 1961:16;245-63. (35.) Tokars J, Miller E, Alter M, Arduino M. National surveillance of dialysis-associated diseases in the United States United States, officially United States of America, republic (2005 est. pop. 295,734,000), 3,539,227 sq mi (9,166,598 sq km), North America. The United States is the world's third largest country in population and the fourth largest country in area. , 1997. Semin Dial 2001;3:75-85. (36.) Everall PH. Problems in the disinfection of class 1 microbiology safety cabinets. J Clin Pathol 1982;35:698-705. (37.) Munro K. A comparative study of methods to validate formaldehyde decontamination of biological safety cabinets. Appl Environ Microbiol 1999;65:873-6. (38.) Hundemann A, Holbrook A. A practical method for the decontamination of laboratories by use of formaldehyde gas. J Am Vet Med Assoc 1959;135:549-53. (39.) Lach VH. A study of conventional formaldehyde fumigation methods. J Appl Bacteriol 1990;68:471-7. (40.) Young LS. Vaporized va·por·ize tr. & intr.v. va·por·ized, va·por·iz·ing, va·por·iz·es To convert or be converted into vapor. va formaldehyde treatment of a textile mill contaminated with Bacillus anthracis. J Appl Bacteriol 1990;68:461-9. Address for correspondence: David A. Ashford, Centers for Disease Control and Prevention, 1600 Clifton Rd., Mailstop C09, Atlanta, GA 30333, USA; fax: 404-639-3059; email: dba4@cdc.gov Ellen A. Spotts Whitney, * Mark E. Beatty, * Thomas H. Taylor, Jr., * Robbin Weyant, * Jeremy Sobel, * Matthew J. Arduino, * and David A. Ashford * * Centers for Disease Control and Prevention, Atlanta, Georgia, USA Ms. Whitney is an epidemiologist in the Meningitis and Special Pathogens Branch, Division of Bacterial and Mycotic mycotic /my·cot·ic/ (mi-kot´ik) 1. pertaining to mycosis. 2. caused by a fungus. my·cot·ic adj. 1. Relating to mycosis. 2. Diseases, Centers for Disease Control and Prevention. Her interests include the epidemiology of anthrax, atypical mycobacterial mycobacterial emanating from or pertaining to mycobacterium. mycobacterial granuloma may be caused by Mycobacterium tuberculosis (see cutaneous tuberculosis), M. disease, and bioterrorism preparedness. |
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