Disinfecting solutions

Condy s fluid A disinfectant solution of calcium and potassium permanganates. 

Deionized water is used in pharmaceutical formulations, for washing containers and plant, and for the preparation of disinfectant solutions. 

Use the disinfectant solution according to the manufacturer s directions to thoroughly clean and disinfect your work area. Wipe the area with paper towels and dispose of the towels as directed by your teacher. Wash your hands with antibacterial soap. 

Using the disinfectant solution, disinfect your work area. 

The first mechanical variant uses a presoaked cotton swab on the surface covered with the disinfectant solution, the second variant uses a presoaked swab without disinfectant on the test surface. Both methods have been tested by Prof. Koller in Vienna and the first variant showed a higher efficacy than the second (using more disinfectant on the surface). 

The most widely used and effective disinfectant solutions are based on iodine (iodophor) with concentrations ranging between 0.05% and 0.1%, but sometimes higher concentrations are recommended. Other agents such as chlorhexidine or chlorine dioxide, peroxide, sodium chloride and lactic acid may also be effective (Wilson et al., 1997) but are not common. Recent trials show positive effects of aloe vera-based dipping agents (Leon et al., 2004). One problem of iodine containing products is their low pH value (<4.0), which is necessary for their antimicrobial activity (Hansen and Hamann, 2003). 

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...

The recommended disinfectant solution must be able to establish a 5-log reduction of each of the inoculated microorganisms within 5 min. 

Automatic fogging systems are available to disinfect rooms. A dense fog is quickly achieved by atomising disinfectant solution through nozzles. 

The experimental disinfectant solutions tested exhibited significant sporicidal activity against B. subtilis spores. The B. subtilis strain used in these evaluations is the same one specified in the AO AC sporicidal test. Spores from... 

Consider that if 10 ml of a cell suspension is removed from a vessel it is replaced by 10 ml of air. It is therefore essential to reduce airborne contamination to a minimum. In an undisturbed room bacteria and fungal spores rapidly settle to the floor or the bench, and hence regular cleaning of the floor and bench with antiseptic solutions is required. The floor of the work room should be free of cracks and should be cleaned daily with a disinfectant solution. The work bench should be swabbed down before and after each use with a solution of 70% ethanol. This also serves to kill cultured cells which may have been spilt and hence prevents their transfer to other cultures (see 2.2). 

Chick s early work at the Lister, undertaken with Charles Martin,37 was on the chemical kinetics of the disinfection process. Of particular importance, she found that the temperature dependence of the disinfectant action did not follow the Arrhenius rate expression instead, the rate increased by as much as seven- or eight-fold for a 10°C increase in temperature, thus showing that warm disinfectant solutions were far better for killing bacteria than cold solutions. This led to her being the co-developer of the Chick-Martin Test for the efficacy of a disinfectant. 

Borazjani RN, May LL, Noble JA, et al. Flow cytometry for determination of the efficacy of contact lens disinfecting solutions against Acanthamoeba spp. Appl Environ Microbiol 2000 66(3) 1057-1061. 

Solubilization has been used for many years in the formulation of phenolic antiseptic and disinfectant solutions. In the case of Cresol and Soap Solution (Lysol) and Chloroxylenol Solution B.P., soap micelles are used to solubilize the phenolic substances. The soap (anionic surfactant) is formed by reaction of potassium hydroxide with a suitable oil such as linseed oil (in Cresol and Soap Solution) or castor oil (in Chloroxylenol Solution). The solubilizing potential of surfactant solutions for hydrophobic species has also been exploited in the design of cholelitholytic solvents for gallstone dissolution with some limited success. 

The aqueous concentration of chlorhexidine normally recommended for contact with mucous surfaces is 0.05% w/v. At this concentration, there is no irritant effect on soft tissues, nor is healing delayed. The gluconate salt (1% w/v) is frequently used in creams, lotions, and disinfectant solutions. 

Phenolic compounds such as cresol, chloro-cresol, chloroxylenol and thymol are frequently solubilised with soap to form clear solutions which are widely used for disinfection. Solution of Chloroxylenol BP, for example, contains 5% w/v chloroxylenol with terpineol in an alcoholic soap solution. 

An appropriate disinfection solution (e.g., 10 % Chlorox) should be used to treat the spill area. The disinfection solution should be... 

Before leaving the immediate area, the decontamination team should remove shoe covers and wipe shoes on pads soaked with disinfectant solution. Other personal protective equipment should be removed for appropriate decontamination or autoclaving. Personnel should then shower using germicidal soap. 

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. 

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