Sterilizing Medical Equipment – Using Dry Heat Sterilizers to Do the Job

by dewi susanti

No matter how clean an object appears on the surface, it might still play host to microscopic bacteria. Standard cleansing techniques such as washing and scrubbing are unable to get rid of or inhibit the activity of these pathogens. Sterilization is the only means of neutralizing disease causing pathogens on varied surfaces.

dry heat sterilizersSterilization by heat is one of the oldest methods of sanitizing materials. This includes tempering an instrument in an open flame or boiling an instrument in hot water. However, there are many instruments that cannot be subjected to the same methods because they are prone to oxidation or are destroyed by moisture. Dry heat sterilizers are the best alternative in this regard. The advantage of using this method is it can also be used to treat porous material such a pottery. It can also be used to sterilize metal instruments and glassware.

How does it work? 

Dry heat sterilizers are the most misunderstood in terms of their working. We’ve divided it into steps to be help you understand better.

1. Placement:

The method involves placing the instrument in a heat chamber or an oven. The item must be wiped dry before placing it into the heat chamber. Also, it must not be placed directly on to the oven rack for it might catch germs present there. Here, the items to be sterilized are subjected to blasts of hot air. The air inside the heating chamber is dry and not moist.

2. Temperature Regulations:

Temperature regulations also matter when using dry heat sterilizers to sanitize medical equipment. The oven is preheated to 160� Celsius (320 �F) for a 2 hour procedure and 170� Celsius (340� F) for 1 hour cycle. The oven must be preheated in advance, minimum 20 minutes prior to putting the instrument into the oven. The heat supply should also be uniform.

After the initial heating, the instrument is left inside the oven itself to cool down for another one or two hours. In this way, it reduces the chances of re-contamination.

3.Sterilization process:

Sterilization by dry heat is achieved by means of conduction/convection. The heat is absorbed by the equipment being treated. It gradually penetrates the deeper layers of the material and raises the temperature of the instrument. The high temperature destroys the pathogens and thereby renders the equipment safe for reuse.


It is an effective alternative for other sterilization methods by heat; however it is not without drawbacks. Since the instrument is heated to very high temperatures, it can be used to disinfect only those materials that can withstand high heat. In order to achieve a completely clean item, one must follow a proper procedure. The entire sterilization procedure lasts for 1 to 2 hours. This is longer than other methods. It does not work for fabrics, rubber ware and plastic ware.

This sterilizer model finds different industrial applications, but they are most widely used in laboratory settings for disinfecting laboratory equipment and medical instruments. Laboratories use specially engineered heat chambers and ovens to sterilize surgical instruments and lab equipment. These chambers are large and allow for several items to be sanitized at the same time. They have strategically positioned vents that direct heated air into the chambers to disinfect instruments.

Dry heat sterilizers are definitely a cheaper alternative to an autoclave. However, they might not be the best option for smaller medical clinics that have a limited amount of equipment that needs to be readily available for use.