They have a slow action against tubercle bacilli and are irritant to skin and eyes. Autoclaving is the commonest method. It uses steam under pressure and is the most reliable way to sterilise instruments. Formaldehyde is irritant to the eyes, respiratory tract and skin. It can also be absorbed by some materials and subsequently slowly released with potentially hazardous results.
Ethylene oxide is a colourless gas which is toxic to inhale.
It is effective against all organisms and does not damage equipment. The operating cycle ranges from 2 - 24 hours so the turnaround time is prolonged and it is a relatively expensive process. Sterilisation by irradiation is an industrial process and particularly suited to the sterilisation of large batches of products. Irradiation can cause serious deterioration of materials and is therefore not a suitable method for the resterilisation of equipment items. Summary of Decontamination Procedures Respiratory equipment Sterilisation is unnecessary since spore-bearing organisms are not a cause of respiratory infection.