Question

discuss the importance of correct chemical solution for disinfection. 2-3 paragraphs.

Answer 1

1) Ans)Disinfectants are chemical agents designed to inactivate or destroy microorganisms on inert surfaces. Disinfection does not necessarily kill all microorganisms, especially resistant bacterial spores; it is less effective than sterilization, which is an extreme physical or chemical process that kills all types of life

The proper use of medical disinfectants can help contain and prevent the spread of harmful bacteria and viruses. Many infectious diseases can be halted in their tracks by the proper use of medical disinfectant products, and by the routine disinfection and sterilization of medical devices.
   Infectious diseases such as tuberculosis, mucormycosis (a flesh-eating fungal infection), and AIDS are mostly caused by pathogens including bacteria, fungi and viruses

Disinfection is the process of eradicating pathogens on the environmental surfaces, reusable medical devices and other inanimate objects. It can be accomplished by using chemical or physical agents. Increasing clinical evidences have shown proper disinfection able to disrupt the transmission pathways, which is further linked to reduced HAIs. Those evidence based infection prevention studies warrants the importance of proper disinfection of environmental surfaces and reusable medical devices in hospitals.

Chemical Disinfectants

Alcohol

Chlorine and chlorine compounds

Formaldehyde

Glutaraldehyde

Hydrogen peroxide

Iodophors

Ortho-phthalaldehyde (OPA)

Peracetic acid

Peracetic acid and hydrogen peroxide

Phenolics

Quaternary ammonium compounds

Alcohol:
Alcohols (ethanol, isopropanol)
Ethanol or isopropanol in concentrations of 70% - 95% are good general-use
disinfectants. They are most effective against lipophilic viruses, less effective against non-lipid viruses, and ineffective against bacterial spores. Because of their quick evaporation rate, it may be difficult to achieve sufficient contact time.

Chlorine compounds (household bleach – 5.25% sodium hypochlorite)
Chlorine-containing solutions have universal disinfectant activity. With proper
concentration and sufficient contact times, hypochlorite solutions can be considered
chemical sterilants since they will inactivate bacterial spores. The downside is that
chlorine compounds are quickly inactivated by excess organic materials and are
corrosive to metals and tissues. Consequently their use in labs has some limitations. In solutions of 50-500 ppm available chlorine, they are effective against vegetative bacteria and most viruses. Bacterial spores require concentrations of 2500 ppm with extended exposure time. Household bleach (5.25% sodium hypochlorite) diluted 1:100
with water yields a disinfectant solution containing to 525 ppm available chlorine; a 1:10 dilution yields 5000 ppm available chlorine. Since the free chlorine is inactivated by light and air, disinfectant chlorine solutions are best made fresh before use.
Formalin Formalin is a 37% solution of formaldehyde gas in water. Diluted to 5% formaldehyde it is an effective disinfectant; at 0.2% - 0.4% it can inactivate bacteria and viruses. Unlike chlorine, formalin does not corrode stainless steel. It has a pungent, irritating odor; exposures must be limited due to its toxicity and carcinogenicity.
Glutaraldehydes These agents are closely related to formaldehyde but seem to be more biologically
active.

Glutaraldehydes are effective against all types of bacteria, fungi, and viruses.
With sufficient contact time they kill bacterial spores. While glutaraldehyde vapors are
less irritating than formaldehyde (formalin), they remain irritating to the eyes, mucous
membranes, and upper respiratory tract. Exposures should be minimized by confining use to a properly functioning chemical fume hood.

Phenols

Phenol solutions have been used for many years as a disinfectant. Their usefulness in
laboratories is limited, however, because they leave a sticky residue on surfaces
following treatment. Concentrated phenol is a highly toxic, corrosive substance that is
easily absorbed through the skin. Use of appropriate personal protective equipment is essential.

Disinfectants work by destroying the cell wall of microbes or interfering with their metabolism. Sanitizers are substances that simultaneously clean and disinfect..
Disinfectants are frequently used in hospitals, dental surgeries, kitchens, and bathrooms to kill infectious organisms.