Disinfection using chemical agents

However, the disadvantages of chemical methods are well-known, including the following. 

The necessity for re-validation for each biological/disinfectant agent combination to be used. 

The susceptibility to inhibition of the disinfecting action by the presence of dissolved and suspended solids, pH, low temperatures etc. 

The neutralisation of the disinfecting agent by unspecified materials in the effluent. 

The necessity to release into the environment often substantial quantities of toxic chemicals. This is a consequence of the need to overdose in an attempt to overcome the neutralisation or inhibition of the disinfectant. 

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Disinfectant A chemical agent used on objects as clothing to destroy or control the growth of microorganisms... 

This section addresses disinfection procedures using chemical agents during which fluids are applied to surfaces with the intention of reducing the count of micro-organisms inside the controlled workspace of an isolator. 

The first industrial use of chlorine was to produce bleaching agents for textiles and paper and for cleaning and disinfecting. These were liquid bleaches (solutions of sodium, potassium, or calcium hypochlorite) or bleaching powder (chlorinated lime). Chlorine was then regarded merely as a useful chemical agent. 

Viruses that contain hpid are inactivated by organic solvents such as chloroform and ether. Those without hpid are resistant to these agents. This distinction has been used to classify virases. Many of the chemical disinfectants used against bacteria, e.g. phenols, alcohols and quaternary ammonium compounds (Chapter 10), have minimal virucidal activity. The most generally active agents are chlorine, the hypochlorites, iodine, aldehydes and ethylene oxide. 

Many of the standard works include only the word disinfection in their title yet deal with all classes of compounds and with a wide range of apphcatioa It is unrewarding to be too dogmatic about these terms many substances can function in both capacities depending upon their concentration and time of contact. A more general term, biocide, is now widely used to denote a chemical agent that, literally, kills microorganisms. 

Uses Wetting agent dyestuffs preparation of phenolic antioxidants plastics, resins, solvent, disinfectant, pharmaceuticals, insecticides, fungicides, and rubber chemicals manufacturing lubricant and gasoline additive possibly used as a pesticide plasticizers. 

Disinfectants are strong chemical agents that inhibit or kill microorganisms (Table 50-1). Antiseptics are disinfecting agents with sufficiently low toxicity for host cells that they can be used directly on skin, mucous membranes, or wounds. Sterilants kill both vegetative cells and spores when applied to materials for appropriate times and temperatures. Some of the terms used in this context are defined in Table 50-2. 

Common definitions of the term disinfection usually aim at its medical aspects related to transmissible diseases and to the killing or irreversible inactivation of the disease-causing organisms by use of chemical agents or physical procedures. This includes the destruction of infectious or other undesirable bacteria, pathogenic fungi or vimses and protozoa on surfaces or any inanimate objects (Block, 1993, Harke, 1987). Thus, disinfection of water, air or surfaces should produce a... 

To fight fire, use foam, CO2, dry chemical. Used as an odorant, disinfectant, solvent, wetting agent, and frothing agent. 

Disinfectants Chemical agents or formulations that are too irritant or toxic on body surfaces, but are used to reduce the level of microorganisms from the surface of inanimate objects to one that is safe for a defined purpose. 

Chlorine is an efficient disinfectant as well as an oxidizing agent, and perhaps is the most frequently used chemical by environmental engineers and scientists since 1800s. The oldest water treatment facilities used only chlorine for water disinfection, which became the foundation of our industrial development. Today chlorine has been used in various forms for sanitary, commercial, industrial, and military applications. This chapter is a sister chapter to the following book chapters in the Handbook of Environmental Engineering series ... 

Disposable equipment should not be re-sterilized or re-used. 2. Ethylene oxide is a difficult process to control and the Department of Health discourages its use in hospitals. 3. Low temperature steam with formaldehyde is of value in the sterilization/disinfection of some heat-sensitive materials. 4. Chemical agents, e.g. gluteraldehyde, hypochlorite. 

Cleaning with chemical agents can be used. They need to be compatible with the membrane to avoid damaging the membrane structure. Some common cleaning agents are acids (strong or weak), caustic (NaOH), detergents (alkaline, non-ionic), enzymes, complexers, and disinfectants. 

B. Superchlorination. Small amounts of water, in units of one litre, may be superchlorinated. Simple chlorination, as is used to disinfect water from naturally occurring bacterial contaminants, is not sufficient to decontaminate water suspected of being contaminated with chemical agents. 

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