Disinfec ting with Heat 433
Pressure steaming
Use pressure steaming to disinfect metal, rubber, plastic,
and cloth. Wash and rinse the materials to be disinfected
and put them in the pressure cooker with water. Close the
lid and heat it on the stove. After it boils, cook at 15 to 20
pounds of pressure for 20 minutes.
Autoclave
An autoclave is a small machine that disinfects things
using steam heat and pressure. Autoclaves have been
used for many years to disinfect medical instruments.
They are used more and more to treat waste as well.
It is safest to use 2 separate machines — one for
reusable instruments and one for waste. For health
centers with very small amounts of waste to be disinfected, a pressure steamer
is less expensive and works as well as an autoclave. It is possible to build gas,
kerosene, or solar-powered autoclaves for areas with no electricity.
Microwave ovens
Microwave ovens heat the moisture in objects
placed inside them. The heat, together with the
amount of time an object is in the microwave oven,
leads to disinfection. Because microwave ovens vary
greatly in power, use care when disinfecting with
this method. To make sure of high level disinfection:
1. Put the waste in a non-metal container with enough water to cover it.
2. P ut a loose-fitting cover over the top of the container to reduce the loss
of water during heating.
3. M icrowave waste materials for at least 20 minutes.
4. Let the container cool before opening. Dispose of any microwaved liquid
waste in a leaching pit (see page 439) or you can safely pour it down the
drain.
Important: Do not put metal objects in a microwave oven. It can ruin
the machine.
After Disinfection
No matter what kind of disinfection you use (chemical or heat), disinfected
waste should be safely stored in bags or disposed of right after disinfection.
Keep waste away from patients, and make sure that infected waste does not
get mixed with disinfected waste.
A Community Guide to Environmental Health 2012