What is it and why is it important?
It is compulsory for all medical establishments to follow specific instructions for the sterilization of working environments and instruments in order to protect both the medical staff and third parties from the risk of contamination from biological agents. The requirements play an indispensable part in the prevention and protection processes for staff in the workplace. They ensure that safety and hygiene standards are met, thus safeguarding the health of staff and consequently both direct and indirect users of the services.
In a dental practice, all of the disinfection and sterilization procedures are based on chemical or chemical/physical methods used to inactivate and destroy any pathogenic micro-organisms on the instruments. If chemical substances are used, it is necessary to take into account the level of toxicity of the sterilization product being used and assess it in comparison with its efficacy.
The importance of the Vacuum test
For autoclave sterilization to be effective, steam must come into contact with the surfaces being sterilised. Because of this, there must be nothing blocking the steam—the sterilising agent—from the surface being sterilised. This is why it is important to ensure that a vacuum is created. If the air is not removed, it can act as an insulating barrier between the steam and equipment, and compromise the sterilization process as a result.Used to verify that the autoclave is effectively capable of creating the vacuum required inside the chamber (DIN 58946-6: 2002).
It is used to check that the sterilization chamber is perfectly sealed, i.e. that there is no decrease in the vacuum level in the hydraulic circuit, highlighting potential pump malfunctions, air leaks from the door gasket or pipe connections, the air tightness of the solenoid valves and whether the vacuum limits set on each machine have been reached.
The test involves performing the vacuum phase; the chamber is kept isolated for a set time, after which it is indicated whether the pressure increase due to any air re-entry is less than a set value.
In accordance with standard EN 13060, the test requires a leak rate of
1.3 mbar/min or less during the 10 minutes that the test lasts for; if the leak rate is higher, the test is a failure and you will have to check the airtightness of the device’s hydraulic circuit.
How it works and when
This test—for class-B autoclaves—is available with all autoclaves that offer a specific cycle. It takes around 20-30 minutes. It should be performed daily and only when the appliance is cold and empty.
At the end of the Vacuum Test, all latest-generation autoclaves produce a paper or digital certificate specifying the date of the test and the result achieved. The result is proof that proper sterilization processes have been adopted and can be stored in sterilization logs.