Table 1.

An Introduction to the Techniques

	Technique	Description	Mechanism of Action	Readily Available
Techniques Achieving Sterilization
Portable Sterilization	Portable Nitrogen Dioxide Sterilizer14	A polypropylene case, in the size of a briefcase.	Non-steam autoclave using nitrogen dioxide gas.	No
	Portable Chlorine Dioxide Sterilizer15,16	A plastic case, in the size of a briefcase. Developed by Natick Soldier Center.	Non-steam autoclave using chlorine dioxide gas.	No
	ROSS M1 Portable Ozone Sterilizer17	A plastic case in the size of a briefcase. Developed for and evaluated by US Special Forces.	Non-steam autoclave using peroxone gas.	No
Pressure Cooking	Specially Designed Low-Cost Autoclave18	Developed at MIT for and used by health care centers in Nepal and marketed under the brand OttoClave.19	Design included a heating element, pressure cooker, pressure sensor, and monitor.	Unknown
	Pressure Cookers20,21	Five commercially available pressure cookers tested on kerosene and gas stoves.	Steam under pressure.	Yes
	Portable Steam Sterilizer22	Originally designed by WHO and now adapted for use in sterilizing intrauterine device insertion instruments.	Steam under pressure.	Unknown
Liquid Chemical Immersion	Liquid Chemicals23	A number of liquid chemicals available, achieving sterility if soaked for up to 12 hours. The most common is glutaraldehyde.	Inactivates microbes if instruments are properly cleaned.23	Yes
Solar Driven	Solar Driven Dry Heat Oven24	Maria Telke’s solar oven; can generate temperatures above 180°C.	Dry heat.	Unknown
	Broadband Light-Absorbing Nanoparticles as Solar Photothermal Heaters25	As light is absorbed by a nanoparticle, a temperature difference is established which converts the liquid into vapor. When the vapor reaches the surface, it is released, resulting in steam generation at lower temperatures than the boiling point.	High-temperature steam.	No
UVC Light	Chlorhexidine Scrub + UVC Light26	Each instrument exposed to UVC light radiation by waving the wand up and down the side of the instrument for 45 seconds.	UVC light disrupts the DNA of microorganisms.	No
Techniques Achieving High-Level Disinfection
Boiling	Boiling27	According to WHO guidelines on sterilization and disinfection methods effective against HIV (1989), if sterilization is not possible, high-level disinfection by boiling for 20 minutes is acceptable.27	High temperature.	No Specific Appliance Required
Liquid Chemical Immersion	Liquid Chemicals23	A number of liquid chemicals are available, achieving high-level disinfection if soaked for 15-30 minutes. The most common is glutaraldehyde.	Inactivates microbes if instruments are properly cleaned.23	Yes

Abbreviation: UVC light, ultraviolet C light