Appendix

1.  Sterilization of acupuncture needles and equipment

Sterilization is defined as the destruction of all microbes, including bacterial spores (Bacillus subtilis, Clostridium tetani, etc.). High-level disinfection is defined as the destruction of all microbes, but spores may survive if initially present in large numbers.

2.  Methods of sterilization

Steam sterilization is the most widely used method for acupuncture needles and other instruments made of metal. It is nontoxic, inexpensive, sporicidal and rapid if used in accordance with the manufacturer's instructions (e.g. time, temperature, pressure, wraps, load size and load placement). Steam sterilization is only fully effective when free from air, ideally at 100% saturated steam. Pressure itself has no influence on sterilization, but serves as a means of obtaining the high temperatures required.

Dry heat can also be used for sterilizing needles and particularly for sterilizing materials that might be damaged by moist heat, but it may cause the needle to become brittle.  It requires higher temperatures and longer sterilization times.

Recommended sterilizing temperatures and times for steam under pressure, and for dry heat, are shown in the table below.

Recommended methods of sterilization
* Steam under pressure (e.g. autoclave, pressure cooker)
Required pressure: => 15 pounds per square inch (101 kilopascals)
Temperature
115°C
121°C
126°C
134°C
Time
30 minutes
15 minutes
10 minutes
3 minutes
* Dry heat (e.g. electric oven)
Temperature
160°C
170°C
180°C
Time
120 minutes
60 minutes
30 minutes


(Source: WHO - GPA/TCO/HCS/95/16 p.15.)

Instruments made of rubber or plastic which are unable to stand the high temperature of an autoclave can be sterilized chemically, at appropriate concentrations and ensuring adequate immersion times (e.g. 6% stabilized hydrogen peroxide for six hours).

For cupping, it is recommended that glass rather than rubber or plastic cups should be used since glass can withstand the higher temperatures required for sterilization.

It should be noted that boiling needles in water is not sufficient for sterilization, nor is soaking in alcohol, since these methods do not destroy resistant bacterial spores or certain viruses.

3.  Disinfection

A high level of disinfection is achieved when instruments are boiled for 20 minutes. This is the simplest and most reliable method of inactivating most pathogenic microbes, including HIV, when sterilization equipment is not available. Boiling should be used only when sterilization by steam of dry heat is not available. Hepatitis B virus is inactivated by boiling for several minutes; HIV, which is very sensitive to heat, is also inactivated by boiling for several minutes. However, in order to be sure, boiling should be continued for 20 minutes.

Chemical disinfection is used for heat-sensitive equipment that may be damaged by high temperatures. Most disinfectants are effective against a limited range of microorganisms only and vary in the rate at which they destroy microorganisms. Items must be dismantled and fully immersed in the disinfectant. Care must be taken to rinse disinfected items with clean water so that they do not become recontaminated. Chemical disinfectants are unstable and chemical breakdown can occur. They may also be corrosive and irritating to skin. Protective clothing may be required. Chemical disinfection is not as reliable as boiling or sterilization.  The agents include:

chlorine-based agents, e.g., bleach
aqueous solution of 2% glutaraldehyde
70% ethyl or isopropyl alcohol.

(Source: WHO - GPA/TCO/HSC/95/16 p.16 and WHO AIDS Series 2, 2nd edition, p.3, 1989.)

4.  Maintenance

All sterilizers should be checked periodically. The sterilizer should be loaded in accordance with the manufacturer's instructions, with enough air space between packages to permit the proper circulation and penetration of steam or hot air. The effectiveness of sterilization should be regularly checked with biological indicators, autoclave control indicators or such other tests as may be devised to ensure that the contents of the load have been subjected to sterilization conditions.

Use of a new pattern of sterilizing box to contain needles is recommended.  The box is made of a special kind of metal sensitive to heat, with air holes that open automatically under high temperature, and close when the temperature falls below 75°C.