Decontamination can be defined as the procedure, treatment, or process that allows a medical device, an instrument such as molecular biology kits, or environmental surface secure and safe to handle. Being a multi-form process, decontamination has four primary types: Cleaning, Antisepsis, Disinfection, and Sterilization.
Decontamination is important for any biomedical research. The effects and importance of decontamination are well explained by M. Dettenkofer (1). The research explains how contaminated equipment can alter the results of research and what measures should be taken in order to make any procedure, process, or research efficient.
All contaminated materials and apparatus or equipment should undergo decontamination before being discarded, stored, or washed. Many healthcare professionals and researchers use an autoclaving method for decontamination. As a healthcare professional or a researcher, if you are working with biohazardous material, you should be responsible for the decontamination of that material, your lab, and its equipment.
There are different levels of decontamination, and each level has unique effectiveness. From sterilization (high-level) to simple cleaning with water and soap, each level provides a different result.
In Sterilization, we use a chemical or a physical procedure to kill all microbial life. This includes highly resistant bacterial endospores.
The disinfection method requires a special chemical to destroy literally all pathogenic microorganisms. This is done with the exception of bacterial spores on equipment and work surfaces. The effectiveness of this method depends upon the number of organisms, their kinds, organic matter, disinfectable objects, and the time of chemical exposure. The effectiveness also depends upon the concentration and temperature.
Antisepsis is an application of the liquid chemical related to antimicrobial living tissue or skin to kill or inhibit microorganisms. This level of decontamination involves swabbing an injection site on an animal or a person. This also includes germicidal solutions for handwashing. Make sure that you follow the recommendations of the manufacturer in order to use the germicides properly, safely, and effectively.
Cleaning is the simplest and the least effective level of decontamination. This involves soap, detergent, and water. This also requires some actions like scrubbing with a brush or a gloved hand. Cleaning might be the least effective, but it is important. The procedure is used before sterilization in order to remove organic material and dust so that the number of microorganisms on an object can be reduced effectively.
For decontamination, there are four categories, both chemical and physical. The methods are Heat sterilization, liquid disinfection, vapors and gases, and radiation. Read the description of these methods below:
Wet Heat is the most dependable and effective type of sterilization. The method is also called autoclaving and steam sterilization. If this method is used, destroying all types of microbial life is easy. This method involves saturated steam that stays under the pressure of about 15 pounds per square inch in order to get a chamber of increment in temperature up to 250F. The temperature remains at this level for about 30-60 minutes.
This method is less effective than wet heat. In this method, you need more temperature and more time to achieve the same results. The method is ideal for killing viable organisms on non-organic objects like glass etc.
Liquid disinfectants are used in this method that may include amines, alcohols, ketones, aldehydes, phenolic compounds, quaternary ammonium compounds, heavy metal salts, alkalis, acids, and halogens. The effectiveness of this method depends upon the type of infection, microorganism you want to destroy. Therefore, in order to achieve the maximum results, find out which disinfectant is great for the target.
Vapors and Gases
Vapors and gases are great if used under closed conditions and in a closed system. For this, you will need to control the temperature and humidity in order to achieve the best results. In this method, agents are gas, vapor, or aerosol phase of hydrogen peroxide, peracetic acid, ethylene oxide, paraformaldehyde, glutaraldehyde, and chlorine dioxide. Hydrogen peroxide has also earned the reputation to be an ideal substance for decontamination.
Ionizing can eliminate microbial life, but this approach is not suitable for lab use.
The UV-C band has a wavelength of 250-270nm. This can effectively eliminate most microbial life in water, air, and on the surface. Microorganisms must be exposed to UV radiation. It is good if cleaning is done before using this method so that the dust cannot provide a shield to microorganisms.
Decontamination is important in many ways. Lab procedures sometimes involve hazardous material. This material may have the potential to affect your health. Also, if microbes are present in the equipment, you may not get the results you want. So, in order to achieve the best results, make sure you use one of the methods of decontamination before you start your lab procedure.
1. Importance of Enviromental Decontamination – A Critical View. M. Dettenkofer, R.C. Spencer. Freiburg, & Bistol : ELSEVIER, 2007, Vol. 65.