Decontamination formaldehyde

Formaldehyde Decontamination of the Laminar Flow Biological Safety Cabinet, (slide/cassette) NAC no. 005137 and no. 003148, National Audio Visual Center (GSA), Washington, D.C., 1976. 

Formaldehyde generated from paraformaldehyde has better penetration, and there are fewer problems with condensation and subsequent need for prolonged aeration than with formaldehyde generated from formalin. If walls and surfaces are not wet with condensation during the formaldehyde treatment process, then aeration and removal of the formaldehyde should proceed rapidly. A small room with nonporous surfaces and no materials or equipment in the room can be cleared of all detectable formaldehyde in less than an hour of aeration. Practical applications of formaldehyde decontamination techniques are covered later in this chapter. 

Post warning signs in conspicuous locations stating DANGER-FORMALDEHYDE DECONTAMINATION IN PROGRESS-DO NOT ENTER. ... 

The development of catalysts for the oxidation of organic compounds by air under ambient conditions is of both academic and practical importance (1). Formaldehyde is an important intermediate in synthetic chemistry as well as one of the major pollutants in the human environment (2). While high temperature (> 120 °C) catalytic oxidations are well known (3), low temperature aerobic oxidations under mild conditions have yet to be reported. Polyoxometalates (POMs) are attractive oxidation catalysts because these extensively modifiable metal oxide-like structures have high thermal and hydrolytic stability, tunable acid and redox properties, solubility in various media, etc. (4). Moreover, they can be deposited on fabrics and porous materials to render these materials catalytically decontaminating (5). Here we report the aerobic oxidation of formaldehyde in water under mild conditions (20-40 °C, 1 atm of air or 02) in the presence of Ce-substituted POMs (Ce-POMs). 

Small Areas Decontamination may not be required. If deemed appropriate, wash all exposed surfaces with soap and water. If more extensive decontamination is desired, fumigate with disinfectant gas or aerosol (e.g., formaldehyde). Follow fumigation with a wash of all surfaces employing a disinfectant such as household bleach. Rinse with water. 

Effect of chemical decontaminants. Exposure to formalin and sodium hypochlorite inactivated both VACV and a large proportion of baculovimses [35, 59, 115], Formaldehyde vapor, as well as in suspension, completely inactivated VACV [35, 95], In line with these findings, formaldehyde has been successfully used as surface disinfectants for insect diets against baculovims contamination [87], Comparably, sodium hypochlorite has been used effectively as a disinfectant of baculovimses and VACV for work areas in laboratories, as well as healthcare and food industry facilities [115],... 

Formaldehyde vapour generated from formaldehyde solution is an effective space disinfectant for decontaminating rooms or buildings. It inactivates vegetative bacteria, bacterial spores, and viruses. Formaldehyde... 

During the decontamination steps, acid streams containing small amounts of actinides and fission products are produced. These streams are evaporated to concentrate the metal ions and recycle them. Nitric acid is recovered from the condensates and recycled. Excess HNO3 may be destroyed by formaldehyde. Fission product concentrates are routed to the aqueous raffinate of the first extractor of the partitioning cycle which contains > 99% of the FP. This constitutes the high level liquid waste (HLLW, or alternatively called HAW, high active waste). All other liquid wastes can be subdivided into intermediate level waste... 

Formaldehyde has frequently been used in the past for decontamination of BSCs as well as entire laboratories. Because of its toxic properties and regulations associated with it use, the use of formaldehyde has declined. Generally, formaldehyde is generated by heating paraformaldehyde (e.g., in an electric fry pan) within the BSC or within the laboratory. The decontamination is carried out for at least 8 hours. The BSC or laboratory must be allowed to ventilate or air out so that the formaldehyde is dissipated. 

For sterihzing small pieces of equipment, ethylene oxide is widely used—but it requires the purchase of special equipment. HPV also requires special equipment, but this can be used for decontaminating entire laboratories and BSCs. Formaldehyde is still used by many because it does not require special equipment and is relatively cheap—nevertheless, regulations may limit the use of this technique. 

Stoppered vials can be left in the chamber and exposed to a sterilising vapour in order to decontaminate the outside of the vials before their removal from the freeze-drier. In this laboratory we have been able to demonstrate that formaldehyde vapour will not permeate stoppered vials which contain freeze-dried samples. 

Disadvantages of using formaldehyde include polymerisation of the agent to form persistent residues which require removal by rinsing after the decontamination exercise. Formaldehyde is corrosive to brass at all temperatures and corrosive to mild steel at high temperatures by the action of formic acid formed by formaldehyde decomposition. Neoprene, nitrile and soft rubbers are attacked at temperatures above 40 °C. 

Temperatures above 100 °C cannot be attained unless the steam is pressurised. Because bacterial spores are only destroyed at temperatures above 110 °C, live steam is therefore not an effective sterilant and consequently is only used to decontaminate freeze-driers when combined with a gaseous biocide such as formaldehyde. 

Aldehydes have also been the subject of a patent application for the prevention of dental calculus formation and for reducing dental caries formation [315]. Glutaraldehyde has also been described as an ingredient of a chewing gum with anti-caries activity [316], Aldehydes, particularly formaldehyde (as formocresol) and glutaraldehyde, are used to disinfect and decontaminate the root canal during certain dental procedures [317, 318, 319] and to disinfect items such as dental stone casts, impressions and dentures [320-324]. 

Spore formation also makes anthrax a difficult microbe to kill. Its persistence was demonstrated by British experiments carried out on Guinard Island in Scotland during World War II. Following the conclusion of tests conducted on Guinard between 1942 and 1943, viable anthrax spores remained for decades. So hardy were they that only disinfectants like formaldehyde were strong enough to adequately decontaminate the island s topsoil. 

For vacuums used in areas where biohazardous agents are found, it is a good idea to perform periodic disinfection of the entire vacuum cleaner with formaldehyde gas or vapor. Use of this procedure must be carefully evaluated, since formaldehyde itself is hazardous (see Section 5.7). In particular, the vacuum should be decontaminated if it is used... 

Formaldehyde for use as a disinfectant is usually marketed as formalin, a solution of about 37 percent concentration, or as paraformaldehyde, a solid polymerized compound. The substance can be utilized for decontamination of large areas (427) or surfaces (451). Formaldehyde in a concentration of 5 percent active ingredient is an effective liquid disinfectant. Formaldehyde at 0.2 to 4.7 percent is often used to inactivate viruses in the preparation of vaccines. Formaldehyde seems to be more effective as a disinfectant against hydrophilic viruses than against lipophilic viruses. Forty percent aqueous formalin (16 percent formaldehyde) is effective in inactivating hepatitis B virus, using a contact time of 12 hours. A 20 percent formalin solution in 70 percent... 

Chemical disinfectants that can be used as space decontaminants include formaldehyde and glutaraldehyde vapor, ethylene oxide, peracetic acid, hydrogen peroxide, and methyl bromide. When these are used in closed systems and under controlled conditions of temperature and humidity, excellent disinfection can be obtained. Residues from ethylene oxide must be removed by aeration ethylene oxide is convenient to use, versatile, and noncorrosive, but it is explosive and extremely toxic and, being a carcinogen, is a potential health hazard. Peracetic acid is corrosive for metals and rubber. 

Formaldehyde is one of the most recommended disinfectants for space decontamination. It is widely used to disinfect safety cabinets, incubators, refrigerators, laboratory rooms, buildings, and other enclosed spaces (427). Formaldehyde vapors can be generated fi om aqueous solutions (formalin) containing 37 to 40 percent formaldehyde by heating or by vaporizing the solution. Formaldehyde gas... 

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