Spore Tests
A close look at the regulations in force
Spore Tests are among the biological tests that must be performed on autoclaves. They are particularly useful because they can provide details of the parameters regarding not only time and temperature, but also – and most importantly – biological inactivation.
How do they work?
The biological indicators used are standard preparations (compliant with the EN 866 standard) of micro-organisms in the form of spores of Bacillus Stearothermophilus, which is especially suitable because:
- It is one of the micro-organisms with the best resistance to humid heat.
- It is not pathogenic.
- It is not toxic.
- It is not pyrogenic.
What is the procedure?
The indicators are provided on strips of paper or in vials. They can be placed in double pouches and put in the parts of the chamber that are deemed most crucial in the process (the corners of the chamber and the air vent) to check whether bubbles of air form.
If the micro-organisms are not living (giving a “Negative” result), it means that the sterilization process has been effective.
Do the regulations say that they are compulsory?
The provisions for these matters are given in the “Guidelines for sterilization as a form of collective protection against biological agents for medical establishment staff (Legislative Decree 81/2008, as amended)” issued in Italy by the National Institute for Occupational Safety and Prevention (Istituto Superiore per la Prevenzione e la Sicurezza sul Lavoro). At point 9.2.4.1, the following information is given:
- Microbiological performance and/or sterilization testing is optional.
- If these tests are carried out, they must be complemented by physical testing.
The sterilization process manager must establish an assessment protocol, which can include a monthly microbiological test. The protocol will be for internal use and as such it must be followed, but it will be separate from the above-mentioned guidelines.
The guidelines establish that the following tests are compulsory and must be carried out on a daily basis:
- Vacuum test
- Steam penetration test for porous materials (Bowie & Dick Test)
- Steam penetration test for hollow materials (Helix Test)
These tests must be included in dental practices’ internal checking protocols.