Safe Cleaning & Disinfecting

By Dr. Magdy Badran 

As COVID-19 continues to spread, people are looking for ways to disinfect their homes. To date, COVID-19 Coronavirus has been responsible for more than 2,471,046 infections globally, causing more than 644,589 deaths.

Disinfectants

Disinfectants are antimicrobial 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.

Sterilization refers to any process that eliminates, removes, kills, or deactivates all microorganisms such as fungi, bacteria, viruses and spores present in a specific surface, object or fluid, for example food or biological culture media. Sterilization can be achieved through heat, chemicals, irradiation, high pressure, and filtration. Sterilization is distinct from disinfection and sanitization, in that those methods reduce rather than eliminate all forms of life and biological agents present. After sterilization, an object is referred to as being sterile or aseptic.

Disinfectants are different from other antimicrobial agents such as antibiotics, which destroy microorganisms within the body, and antiseptics, which destroy microorganisms on living tissue. Disinfectants work by destroying the cell wall of microbes or interfering with their metabolism.

Sanitization

Sanitization is the process of reducing microbial contamination to an acceptable “safe” level without necessarily going through sterilization. The pathogenic microorganisms are reduced in number so that they are no longer harmful. Some viruses and spores are not affected by sanitization. Sanitizing needs to be done often enough so that you avoid having thick layers of bacteria (biofilms) developing.

Clean First Before You Disinfect

Dirt and organic material can render disinfectants less effective because they can hide the microbes, absorb the disinfectant ingredients and reduce the germ-killing ability of some disinfectants. Frequent and correct cleaning of high-risk and high-touch areas with proper equipment will remove microbes. Microfiber cloths and mops are recommended for the removal of microbes.

First, use a cleaning solution to remove visible soil from surfaces. Rinse the surfaces with fresh clean water (this helps remove chemical residue, which can attract more soils). Cleaning works by using water to physically remove germs from surfaces. This process does not necessarily kill germs, but by removing them, it lowers their numbers and the risk of spreading infection.

A universal solvent is a substance that dissolves most chemicals. Water is called the universal solvent because it dissolves more substances than any other solvent.

High-Touch Areas

While it's smart to try and minimize the spread of germs, instead of trying to rip in and completely disinfect the whole house, start with high-touch areas. High-touch areas are surfaces touched frequently and by a variety of hands over the course of the day. High-touch areas include door handles, faucet handles, handrails, shared desks, push bars, drinking fountains, remote controls, keys, mobile phones and so forth. Areas touched by only one person, such as a personal computer keyboard, do not pose the same risk.

Alcohol

Ethyl alcohol (70%) is a powerful broad-spectrum germicide and is considered generally superior to isopropyl alcohol. Alcohol is often used to disinfect small surfaces (e.g. rubber stoppers of multiple-dose medication vials, and thermometers) and occasionally external surfaces of equipment (e.g. stethoscopes and ventilators).

In the healthcare setting, “alcohol” refers to two water-soluble chemical compounds—ethyl alcohol and isopropyl alcohol—that have generally underrated germicidal characteristics. Alcohols are rapidly bactericidal rather than bacteriostatic against vegetative forms of bacteria; they also are tuberculocidal, fungicidal, and virucidal but do not destroy bacterial spores. Their cidal activity drops sharply when diluted below 50% concentration, and the optimum bactericidal concentration is 60%–90% solutions in water (volume/volume).

The most feasible explanation for the antimicrobial action of alcohol is denaturation of proteins. This mechanism is supported by the observation that absolute ethyl alcohol, a dehydrating agent, is less bactericidal than mixtures of alcohol and water because proteins are denatured more quickly in the presence of water.

Ethyl alcohol, at concentrations of 60%–80%, is a potent virucidal agent inactivating all the viruses. Alcohols have been used effectively to disinfect oral and rectal thermometers, hospital pagers, scissors, and stethoscopes.

Since alcohol is flammable, limit its use as a surface disinfectant to small surface-areas and use it in well-ventilated spaces only. Prolonged and repeated use of alcohol as a disinfectant can also cause discoloration, swelling, hardening and cracking of rubber and certain plastics.

Bleach

Bleach is a strong and effective disinfectant – its active ingredient sodium hypochlorite is effective in killing bacteria, fungi, and viruses. Diluted household bleach disinfects within 10–60 minutes contact, is widely available at a low cost and is recommended for surface disinfection in health-care facilities.

However, bleach irritates mucous membranes, the skin, and the airways; decomposes under heat and light; and reacts easily with other chemicals. Therefore, bleach should be used with caution; ventilation should be adequate and consistent with relevant occupational health and safety guidance. Improper use of bleach, including deviation from recommended dilutions (either stronger or weaker), may reduce its effectiveness for disinfection.

Hazards of Disinfectants

Disinfectants have been linked to acute and chronic health issues. Ingredients such as acids, ammonia, bleach, and disinfectants are asthma irritants. Some of the chemical disinfectants are irritating to the skin, eyes, and respiratory system. The highly corrosive disinfectants could inflict serious damage if they come into contact with the skin or eyes. The airborne disinfectants would also cause respiratory problems if used in poorly ventilated areas.

Chemical disinfectants could be hazardous if they are not properly handled. Some of the chemical disinfectants are flammable and explosive. They may react with incompatible chemicals violently and generate toxic gases. All chemical disinfectants are, by their nature, potentially harmful or toxic to living organisms.

Disinfectants often contribute to poor indoor air quality and may contain chemicals that cause cancer, reproductive disorders, asthma, immediate allergic reactions, itching, urticaria, angioedema , anaphylaxis, eye irritation, central nervous system impairment, and other human health effects.

Overuse of some disinfectant products can potentially create microbes that are resistant to particular disinfectants or that become “superbugs.”

There are two potential occupational exposure hazards when using hypochlorite solutions. The first is the production of the carcinogen bis-chloromethyl ether when hypochlorite solutions come in contact with formaldehyde. The second is the rapid production of chlorine gas when hypochlorite solutions are mixed with an acid. Care must also be exercised in using chlorine – based disinfectants which can corrode or damage metal, rubber, and other susceptible surfaces.

While alcohol or chlorine can be useful in disinfecting surfaces, neither will kill viruses that have already entered your body. In addition, spraying these substances can be harmful to mucous membranes (like eyes, mouth, etc.) and clothes.

To read more articles by Dr.Magdy Badran, press here