In late March, we temporarily closed our 14 California-wide studios due to the Covid-19 pandemic. Even though government regulations okayed our reopening in June, we decided to remain closed for a little longer for your safety and ours due to the high contact nature of our business.
We are going to be reopening soon and we just want everyone to be educated on hygiene for the safety of all. In this post, we’ll be discussing two decontamination processes – disinfection and sterilization.
Basic Distinction between Disinfection and Sterilization
Disinfection is the killing or reduction of harmful microorganisms from various objects and surfaces while sterilization is simply killing all microorganisms (whether harmful or not). This is what really sets both processes apart. Sterilization also eliminates the spores of organisms that can be found on objects, surfaces, in liquids, medications or anywhere else they are present.
The extreme nature of sterilization makes it suitable for hospital use, surgical procedures and in industrial and laboratory processes. Disinfection is less extreme and this makes it more suitable for everyday use.
The major way to disinfect is by using chemicals called disinfectants. Disinfectants vary according to strength, toxicity, ease of use and cost. You might find some disinfectants to be very effective against a wide variety of germs while others might be limited in the number of germ species they can kill.
Sterilization on the other hand, can be carried out by three major methods: physical (which involves using heating, filtration and radiation techniques), chemical (this involves making use of liquid and gaseous chemicals) and physiochemical (a method that combines attributes of the physical and chemical sterilization methods).
Types of Disinfectants
- Air Disinfectants: Examples of chemicals used include triethylene glycol and propylene glycol. These disinfectants are spread in the air either as aerosols or in vapor form. They are meant to be dispersed at an appropriate concentration in order to significantly reduce the number of infectious microbes in the air.
- Alcohols: Ethanol and isopropanol are some of the most commonly used alcohols for disinfecting. Your hand sanitizer is an example of an alcohol based disinfectant. At high concentration levels, alcohols can be used to kill viruses such as the coronavirus, HIV, hepatitis B, hepatitis C and more. They are relatively safe to use in homes, although you have to be cautious around inflammable items. They are also quite inexpensive.
- Aldehydes: Formaldehyde and glutaraldehyde are examples of aldehydes notable for their disinfectant properties. Asides being able to kill and reduce germs, they are to some extent able to kill spores and fungi.
- Oxidizing Agents: Common household bleach (sodium hypochlorite solution) is one of the most inexpensive disinfectants for home use. Thanks to the strong oxidizing nature of chlorine and oxygen, household bleach kills germs that can be found on surfaces, toilets, drains, pools, sinks and more.
- Phenolics: Chemicals like phenols and chloroxylenol are phenolics used for disinfection. Phenolic compounds are the active ingredients in popular disinfectants such as Dettol, IZAL, mouthwashes and others.
- Quats: They are also known as quaternary ammonium compounds. An example of these chemicals is benzalkonium chloride. Although they can be classified as low level disinfectants, they are still quite effective nonetheless.
- Biguanides: Polyaminopropyl biguanide is a biguanide polymer known for its disinfectant and preservative properties. It is used for skin disinfection and it is also found in chemicals used for cleaning contact lenses. It is highly effective against bacteria at very low concentration levels.
- UV Light: High intensity shortwave ultraviolet light can be used to significantly reduce the number of microbes on various materials.
- Sodium Bicarbonate: The common baking soda is also known to be a highly effective disinfectant.
Types of Sterilization Methods
- Steaming: This process is carried out in machines known as autoclaves. These machines make use of steam heated to temperature levels of 121 – 134oc (250 – 273oF) to sterilize objects. This method is used to eliminate all bacteria, fungi, viruses and bacterial spores.
- Heating: Dry heat, boiling, tindalization, incineration and flaming are all heating procedures that can be used to kill and inactivate microbes in different objects such as powders, glass and metals. Boiling objects in water for about 15 minutes is enough to kill most microbes except bacterial spores.
Tindalization is one heating method that can kill spores as well as other microorganisms. It involves boiling an object in water for 20 minutes and cooling, then repeating the boiling and cooling process for three times. Dry heating is usually reserved for powders and other items that can withstand very high temperatures of heat. - Chemical Sterilization: Chemicals such as bleach, ozone, glutaraldehyde, formaldehyde, pthalaldehyde, ethylene oxide, hydrogen peroxide, peracetic acid, silver and more are examples of substances that can be used to sterilize items that are not heat resistant (like plastics, electronics, fiber optic materials, biological substances, etc).
Ozone and ethylene oxide are gases used in oxidizing most organic substances. Although bleach, glutaraldehyde and formaldehyde are also disinfectants, they can be used to sterilize materials in higher concentration levels. The materials to be sterilized are usually immersed in them for long periods of time in order to achieve effective sterilization. - Radiation Sterilization: Disposable medical equipment such as needles, syringes and cannulas can be sterilized using x-rays, gamma rays, electron beams or subatomic particles. Biological safety cabinets can also be sterilized by irradiation and reused.
- Sterile Filtration: This is a slow process carried out using pores that are smaller in size than the microorganisms that need to be filtered out. This process is ideal for clear liquids that cannot withstand heating, chemical and radiation sterilization methods.