General Disinfectant Solution

A poly( -vinyl-2-pyrroHdinone)-iodine complex [25655-41-8] (PVP-iodine), has been used extensively in hospitals and elsewhere because of its germicidal, bactericidal, fungicidal, and generally disinfecting properties (150). It is sold as a solution that contains about 10% available, or active, iodine and about 5% inactive iodine, in the form of iodide ion (see Disinfectants and antiseptics Industrial antimicrobial agents). 

Phenols are considered to be low-to-intermediate level disinfectants, appropriate for general disinfection of noncritical and semicritical areas. They are not sporicidal and should not be used when sterilisation is required. They are dispensed in aqueous formulations or in mixed water—alcohol solutions. Levels of 400—1300 ppm in the diluted formulation are typical. 

Phenol was originally recovered during the coking of coal, essentially being a by-product. Eventually, commercial routes were developed based on benzene (from coal or petroleum) for example, sulfonation of benzene to ben-zenesulfonic acid followed by reaction with water to phenol plus regenerated sulfuric acid. Phenol is used to make plastics (phenol-formaldehyde and epoxy resins) and textile fibers (nylon). Phenol is also used in solution as a general disinfectant for cleaning toilets, stables, floors, drains, etc. and is used both internally and externally as a disinfectant for animals. 

Other major uses of phenol include the production of caprolactam (15%), aniline (5%), alkylphenols (5%), xylenols (5%), and miscellaneous uses (1%) (CMR 1996). Phenol is used as a slimicide (a chemical toxic to bacteria and fungi characteristic of aqueous slimes) and as a general disinfectant in solution or mixed with... 

Figure 3.2. Generalized clean room design. Entry of personnel occurs via changing rooms, where the operators first remove their outer garments and subsequently put on suitable clean room clothing (see e.g. Figure 3.3). All raw materials, portable equipment, etc. enters the clean room via a transfer lock. After being placed in the transfer lock, such items are sanitized (where possible) by, for example, being rubbed down with a disinfectant solution. They are then transferred into the clean room proper, by clean room personnel. Processed product usually exits the clean room via an exit transfer lock and personnel often exit the room via a changing room separate from the one they entered (in some cases, the same changing room is used as an entry and exit route). Note that, in practice, product may be processed in a number of different (adjacent) clean rooms...

Phenol (C5H5OH) is a weak acid used as a general disinfectant and in the manufacture of plastics. Calculate the pH and the concentrations of all species present (H30+,C6H50, C6H50H, and OH-) in a 0.10 M solution of phenol (Ka = 1.3 X 10-10). Also calculate the percent dissociation. 

Black fluids and white fluids are prepared by solubilizing the high boiling point tar acids. Black fluids are homogeneous solutions, which form an emulsion on dilution with water. White fluids are finely dispersed emulsions of tar acids, which on dilution with water produce more stable emulsions than do black fluids. Both types of fluid have good bactericidal activity. Preparations are very irritant and corrosive to skin, however, they are relatively inexpensive and are useful for household and general disinfection purposes. They must be used in adequate concentrations as activity is reduced by organic matter and is markedly affected by dilution. 

The iodine you buy at the drugstore is usually an ethanol solution of elemental iodine (I2). Iodine is a general disinfectant, meaning that it kills all sorts of pathogens, including spores, which are notoriously difficult to kill. 

Iodine works as a general disinfectant and can be used with alcohol for use as a skin antiseptic or with other substances for general disinfecting purposes. Exposure can include irritation of the eyes and mucous manbranes, headaches, and breathing difficulties. Crystalline iodine or strong solutions of iodine may cause severe skin irritation because it is not easily removed and may cause burns. The OSHA PEL sets a ceiling for iodine 0.1 ppm according to 29 CFR 1901.1000 Table Z-1. 

Clear soluble fluids. Cresol is a mixture of o-, m- and p-methyl phenol (Fig. 10.7A). Because of its poor solubility, it is solubilized with a soap prepared fiom linseed oil and potassium hydroxide. It forms a clear solution on dilution. This preparation, known as Lysol (Cresol and Soap Solution BP 1968) has been widely used as a general purpose disinfectant but has largely been superseded by less irritant phenolies. 

This preservative is also comparatively new to ophthalmic formulations and has been used as a disinfectant in contact lens solutions. Polyaminopropyl biguanide (polyhexamethyl biguanide) also is a polymeric compound that has a low toxicity potential at the concentrations generally used in these solutions [141, 149, 150]. 

The chemistry of ozone in aqueous solutions and the health effects are complex. It is clear that ozone reacts with water products in the water supply to form numerous disinfection byproducts. However, the general pattern that emerges from most studies is that the reaction byproducts of ozonation appear to be less toxic than those produced by chlorination. 

Chlorine dioxide forms a true solution in water it does not hydrolyze as chlorine does. Therefore, it is very volatile (700 times more volatile than hypochlorous acid) and, therefore, can easily volatize in RO pretreatment systems, leaving the feed water without a disinfectant residual. For this reason and the fact that most chlorine dioxide is generally in equilibrium with free chlorine, makes it unattractive for RO feed water disinfection. 

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