Disinfectants neutralizing agents

TSA-filled plates (the media contain neutralizing agents for disinfectants) for testing the hands... 

Prepare sterile plate contain 25 ml of TSA with neutralizing agents to the applied disinfectant. 

Products and Uses Various applications include brick mortar, plasters, cements, depilatory (hair remover), disinfectants, water softener, and purifier of sugar juices. Also useful as food additive buffer, firming agent, neutralizing agent, and miscellaneous general purpose food chemicals. Also an important agricultural commodity. 

Appropriate disinfectant should be applied following any spill of potentially infectious materials or at the end of daily work to decontaminate laboratory work surfaces. Spill kits (containing absorbent pads and/or neutralizing agents) should be prepared for all frequently used chemicals or biological waste. 

Peroxides are very toxic to the cornea of the eye. After the disinfection cycle, and before placing the lens in the eye, hydrogen peroxide must be completely neutralized by reducing agents, catalase, or transition metals, such as platinum. 

A very commonly used disinfectant is ethanol-water in neutral or, preferably, in acidic conditions. Aqueous ethanol displays its best germicidal efficiency at a concentration of 60 to 70%. However, the most commonly used concentration in industry is about 20%, because higher concentrations require specific explosion-proof facilities. At 20%, ethanol has no sporicidal effect, its effect on viral inactivation is only partial and it does not destroy pyrogens (it only tends to destabilize large molecular aggregates of lipopolysaccharide molecules). For these reasons, 20% ethanol can only be considered as a bacteriostatic agent. Mixtures of ethanol with bases or acids are somewhat more sporicidal, but are not sufficient to provide sterilization at short incubation times and low temperatures. 

X (Disinfection by-product) permanent wave neutralizing solutions flour maturing agent dough conditioning agent fish paste beer and cheese... 

Compared with suspended (planktonic) cells, bacteria on surfaces as biofilms are invariably phe-notypically more resistant to antimicrobial agents. With biofilms, suspension tests can be modified to involve biofilms produced on small pieces of an appropriate glass or metal substrate, or on the bottom of microtitre tray wells. After being immersed in, or exposed to the disinfectant solution for the appropriate time interval, the cells from the biofilm are removed, e.g. by sonication, and resuspended in a suitable neutralizing medium. Viable counts are then performed on the resulting planktonic cells. 

If the final chlorine-disinfected effluent is to be discharged to a sensitive watercourse, dechlorination may be necessary to avoid problems from the toxicity of the residual chlorine. After a 20- to 30-min holding time for completion of the disinfection to take place, the treated effluent is dechlori-nated by adding a reducing agent such as sulfur dioxide to convert chlorine to chloride, followed by pH neutralization with lime (Eqs. 5.20 and 5.21). 

At millimolar levels of molecular chlorine, the reaction goes to 99% completion in a matter of a few seconds. Above pH 4.4, essentially no molecular chlorine remains in aqueous solution. Hypochlorous acid is a weak acid (pKa approximately 7.5) and thus, near neutrality, both the protonated form and the anion occur at appreciable levels. HCl-free solutions may be prepared by adding salts such as sodium hypochlorite (NaOCl, commercially available as a stabilized 5.25% [0.7 M] solution as a fabric bleach). Either chlorine gas or hypochlorite solutions can be used in large-scale water chlorination applications. In addition to water treatment, chlorine is also used as a disinfectant for beef, pork, and poultry carcasses and also as a bleaching agent for paper pulp and cake flour (Wei et al., 1985). The disinfecting ability of aqueous chlorine is closely associated with its vigorous oxidant character the redox potential for the reactions... 

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