Terms aseptic and sterile are significant concerns, and sometimes it is not easy to understand the differences between the two terms. For example, in the case of environment classification, some people might say the “sterile area”, and others use the term “aseptic area”.
USP General information chapter no. 1116 describes The terms Aseptic and Sterile are not synonymous. It is a broad concept, and the US FDA does not include it in the guidelines.
Difference between Aseptic and Sterile Area
Sterile area:
Sterile means having an entire absence of viable microorganisms or organisms that have the potential to reproduce. No life at all like (bacteria, fungi, and viruses)
Sterile is basically, the surface and product contact part that is free from microbial contamination. The products that are free from all pathogens and microorganisms are called sterile products, such as surgical gloves (sterile surgical gloves), small volume parenteral, and large volume parenteral and ophthalmic products.
The technique used for the removal of all harmful microorganisms or pathogens is called the sterile technique.
Sterile Technique
The best sterile technique is to follow the procedure (SOP), entry-exit procedure, handling of equipment, gowning procedure, and sanitization process.
Sterile technique is a critical skill that is used in numerous fields such as microbiology, molecular biology, and cell biology. Before beginning any experiment make sure that you are wearing the appropriate personal protective equipment, including a lab coat, gloves, and, if necessary, safety glasses.
Body flora can be a common cause of contamination in reagents. To reduce the risk of contaminating your samples with body flora, ensure that your arms and wrists are covered by a cuffed lab coat or disposable arm cuffs. While gloves are meant to protect users from the material they are working with, they also protect the material from user contamination. To keep your gloves clean, avoid touching your skin and hair, as well as your cell phone, writing utensils, or other unsterilized objects.
Before starting a new task, Always change your gloves if you touch something unsterile. Clear the workspace of unnecessary materials. Set up all materials so that they are within arm’s reach with clean and dirty items clearly separated.
It is recommended to work from left to right with all clean items stored on the left and waste bins to the right. If you are going to be using a Bunsen burner or candle jar, make sure that the space around the burners is free of loose papers or laboratory wipes. Finally, wipe down the workspace and pipettes with 70% alcohol and allow them to evaporate.
Before beginning a task, examine all of your materials for signs of contamination or signs that the sterility may have been compromised. Check all autoclaved items to ensure that the indicator tape has changed colors. For items that are covered with foil check for tears or holes for capped items, and ensure that the cap has been tightly sealed.
When working with agar dishes, examine the dishes for signs of microbial growth. Foil is often used as a cover for bottles and beakers. Before beginning your work, gently loosen the edges of the foil, so it is easier to remove. When ready, gently lift the foil with one hand and keep it upright, to prevent contamination of the sterile side.
Metal objects such as forceps and spreaders are used and reused frequently in the lab. While these items can be sterilized in an autoclave, it is often more convenient to disinfect them with alcohol and a burner. To sterilize, dip the portion of the instrument that will be used for the procedure in 70% alcohol.
Aseptic area:
Aseptic means a pathogen/microorganism-free area. The limits of microorganisms are present there. An aseptic process prevents contamination by excluding microorganisms.
Aseptic technique:
The aseptic technique is a type of practice used to reduce the number of microorganisms and other life forms in order to maintain a sterile or clean environment. For example; employing aseptic technique is by washing hands with soap.
For practical purposes, if somebody wants an area free of microorganisms, not making it sterile but wants to keep it bacteria or pathogen-free for a long time to keep the product safe, then follow an aseptic technique like many food cold chains are following these aseptic conditions.
Aseptic process for handling sterile (sterilized) materials under a controlled environment to carry out microorganisms at the minimum level.
In any environment where human operators are present, microbial contamination at some level is inevitable. Even the most cautious clean-room environment design and operation will not eliminate the shedding of microorganisms if human operators are present.
Thus, an expectation of zero contamination in minor locations during every aseptic processing operation is technically impossible and thus is unrealistic.
If we mention the classification of the area where sterile products are being manufactured, it is better to mention an aseptic area or controlled area, not a sterile area.
Conclusion:
Even in Pharmacopoias and guidelines, the microbial limit of the class A area is critical, and the most cleaned area for sterile manufacturing products is <1 CFU. But we can’t consider it sterile. That’s why there is always a threat of sterile product contamination in aseptic areas if the proper practice is not followed.
