In general, dry heat sterilization of items is performed at 160°C and can last up to 2 hours. Dry heat sterilization is a technique that can kill bacteria and bacterial germ cells with high temperature in a dry environment, and it is mainly suitable for objects that cannot tolerate hot and humid steam and cannot be sterilized with high pressure steam. Usually, the objects can be sterilized by dry heat directly in the oven.
I. What is the usual temperature and time for using dry heat sterilization
1. Generally speaking, if dry heat sterilization is applied to common items, then the optimum temperature is 160°C and the time can last for 2 hours. If you sterilize glass syringes and other items, the optimum temperature is 170°C and the sterilization time is 1 hour. The methods of dry heat sterilization include dry baking, cautery or incineration, infrared, microwave, etc.
2, the principle of dry heat sterilization method is to kill bacteria and bacterial germ cells with high temperature in a dry environment, and it works on items that cannot tolerate moist heat steam and cannot be sterilized by high pressure steam. For example, chemicals that must be kept dry, or anhydrous oils, ointments, glycerin, etc. can be sterilized by dry heat sterilization.
3. Sterilization can be done directly in the oven. Since dry heat sterilization is more damaging to some non-heat resistant materials, dry heat sterilization cannot be used on non-heat resistant materials.
Second, what is the difference between dry heat sterilization and wet heat sterilization?
1、Different sterilization effect
At the same temperature, the sterilization effect of wet heat is better than that of dry heat. Since the temperature required for protein coagulation is related to its water content, the greater the water content, the lower the temperature required for coagulation. Wet heat sterilization of the bacterium protein absorption of water effect is better, but the dry heat sterilization of water absorption effect will be poor, so the effect of wet heat than dry heat is much better.
2, the sterilization temperature is different
Dry heat sterilization requires a higher temperature than wet heat sterilization. Dry heat sterilization is generally carried out using a dry oven, heating 160-180 ° C, time to maintain 2 hours, it can kill all microorganisms. While wet heat sterilization only requires boiling at 100°C and time keeping for 5 minutes to kill the bacterial propagules.
3. Different sterilization medium and time
Dry heat mainly uses air, while wet heat uses water vapor. Dry heat generally needs to be kept for 30 minutes, 1 hour, 2 hours and other time periods, but the whole process of wet heat is only less than 1 hour.
