Disinfection dilution effect

One advantage of this form is that the disinfectant is used at the concentration intended by the formulator. When the disinfectant cleaner is a dilutable, effective disinfection depends on the consumer making the dilution or using the product at the dilution recommended by the formulator. Consumers are... 

There are two reasons why the concentration of quaternaries is beheved to remain at a low level in sewage treatment systems. First, quaternaries appear to bind anionic compounds and thus are effectively removed from wastewater by producing stable, lower toxicity compounds (205). Anionic compounds are present in sewer systems at significantly higher concentrations than are cations (202). Second, the nature of how most quaternaries are used ensures that their concentrations in wastewater treatment systems are always relatively low but steady. Consumer products such as fabric softeners, hair conditioners, and disinfectants contain only a small amount of quaternary compounds. This material is then diluted with large volumes of water during use. 

Sahcyhc acid USP, EP, and other pharmacopeia grades are used medically as antiseptic, disinfectant, antifungal, and keratolytic agents. Sahcyhc acid is formulated in lotion or ointment formulations for the treatment of dandmff, eczema, psoriasis, and various parasitic skin diseases. Because the keratolytic property of this aromatic acid has use in the safe removal of dead skin cells from the surface of healthy skin, the acid is used in concentrated sahcyhc acid solutions or suspensions to remove warts and corns. In more dilute form, sahcyhc acid preparations have found use in dandmff and eczema treatment. Sahcyhc acid has been considered and found effective by the Advisory Committees to the FDA in various over-the-counter (OTC) dmg regulated uses. Among these are acne products, dermatitis, dry skin, dandmff and psoriasis products, and foot care products (24). 

Whereas these preparations do not possess the high bacteriostatic activity of quaternary ammonium germicides, they have the alternate advantage of being rapidly functional in acid solution. In comparative experiments of several different disinfectants, the acid—anionic killed bacteria at lower concentration than five other disinfectants. Only sodium hypochlorite and an iodine product were effective at higher dilution than the acid—anionic. By the AO AC use dilution test, the acid—anionic killed Pseudomonas aeruginosa at 225 ppm. Salmonella choleraesuis at 175 ppm, and Staphylococcus aureus at 325 ppm (172). 

The effects of concentration or dilution of the active ingredient on the activity of a disinfectant are of paramount importance. Failure to be aware of these changes in activity is responsible for many misleading claims concerning the properties of a disinfectant. 

PHENOL COEFFICIENT. In determining the effectiveness of a disinfectant using phenol as a standard of comparison, the phenol coefficient is a value obtained by dividing the highest dilution of the test disinfectant by the highest dilution of phenol that sterilizes a given culture of bacteria under standard conditions of time and temperature. 

Boric acid has also been used therapeutically in the form of suppositories to treat yeast infections, and in dilute concentrations as a mild antiseptic, although it has been superseded by more effective and less toxic disinfectants. See Section 14. 

Phenols (Fig. 17.7) are widely used as disinfectants and preservatives. They have good antimicrobial activity and are rapidly bactericidal but generally are not sporicidal. Their activity is markedly diminished by dilution and is also reduced by organic matter. They are more active at acid pH. The main disadvantages of phenols are their caustic effect on skin and tissues and their systemic toxicity. The... 

Routine cleaning and disinfection procedures are effective for decontaminating automated analyzers. Laboratory staff should disinfect analyzers after use following manufacturer recommendations or with a 5,000 parts per million solution (1 100 dilution) of sodium hypochlorite (1/4 cup of household bleach to 1 gallon of water). 

A US Environmental Protection Agency (EPA) registered hospital disinfectant or a 1 100 dilution of household bleach (1/4 cup per gallon of water) is effective as a disinfectant. However, for grossly soiled surfaces, such as those contaminated with vomitus or stool, staff should use a 1 10 bleach dilution. 

Argentofenol is a disinfectant mouthwash recommended to be dabbed on the mucous membranes every other day. It contains up to 35% phenol. Phenol is still used in medicine and dentistry, sometimes at high concentrations. Side-effects remain rare, as the product is relatively diluted, applied in small quantities or little surfaces and therefore readily eliminated, even when applied repeatedly during the day. There is plenty of time for the liver to detoxify and the kidneys to eliminate the phenol. 

Disinfection is also a benefit desired by consumers in toilet bowl cleaning. This can be achieved with quaternary ammonium surfactants, as in bathroom and allpurpose cleaners. Quats are effective bactericides at both low (1 to 4) and high (8 to 12) pH and so are compatible with very acidic toilet bowl cleaners. One of the problems with disinfection is knowing whether the product has been used at the proper dilution, and one toilet bowl cleaner formula gives the signal via a pH-dependent dye [375],... 

Sodium hypochlorite (NaOQ), sold as Qorox, is used as a household disinfectant and deodorant but is also used to disinfect swimming pools, dairies, food-processing equipment, and kidney dialysis units. It can be used to treat drinking water of questionable quality. Addition of 1 /2 teaspoon of household bleach (5.25% NaOQ) to 2 gallons of clear water renders it drinkable after 1 /2 hour. The Centers for Disease Control even recommend a 1 10 dilution of bleach as an effective disinfectant against human immunodeficiency vims, the virus that causes acquired immune deficiency syndrome (AIDS). 

Ishidate et al. 133,205-208 found that isoxazolidinium salts 47a and the like are effective in the therapy of malignant tumors and have strong biological activity toward Yoshida sarcoma. It appears that the salt 47d is inactive to Yoshida sarcoma.153,56,2°9 The relation between the size of the alkyl substituent in the salt 75 and its antibacterial action was investigated. The bacteriostatic action is maximal with R = CI2H2J, which is still active toward Staphylococcus aureus 209P with the maximum dilution of 400,000. For use as a disinfectant or a bacteriocide the salt of 75 is possible.30... 

For final agricultural application, the concentrated product must be diluted with water to make a 2 % solution, which is applied with compressed air by hand held or power spray equipment. In the field, as shown in Fig. 6.6-37, the disinfectant solution surrounding the microcapsules evaporates, providing the disinfectant action. Then, the insecticide diffuses through the capsule wall and becomes available on the outside surfaces in small, highly effective amounts of the active substance. As the insecticide dissipates it is replenished by more chemical from the inside. Thus, the product is still working after most other insecticides have lost their effect. 

Household bleach contains sodium hypochlorite. A 1 10 dilution of bleach is effective for disinfection of a direct blood spill on a porous surface. In addition to inactivating HIV. sodium hypochlorite solutions have disinfectant activity against other viruses including hepatitis B virus. The answer is (D). 

Sodium borate is a white powdery material that, when diluted in water, forms a cleaning solution. Powdered borax is used as a deterrent for pests such as mites and cockroaches. It can be caustic in high doses, but in low concentrations is an effective disinfectant. It s commonly found in laundry detergents, some hand soaps, and it can also be found in teeth bleaching solutions. 

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