Preventing low temperature failure
Temperatures in the winter months can pose particular challenges for rescue workers, as low temperatures below 10 °C can reduce the efficacy of disinfectants. Simple measures can be taken to counteract this effect known as “low temperature failure”.
Apart from a few exceptions, at low temperatures, disinfection processes are considerably slower than at higher temperatures [1]. This has serious consequences for the use of disinfectants, which are usually used in the medical field at room temperature, i.e. 18 to 23 °C: they are sometimes significantly less effective.
The extent to which the efficacy of a disinfectant is influenced by low temperatures depends on the respective active ingredients: aldehydes and organic acids show the greatest loss of efficacy at low temperatures.
In the case of quaternary ammonium compounds (QACs), biguanides and amphoteric surfactants, however, low temperature failure is less pronounced. Disinfectants with alcohols and active oxygen as active ingredients are even less sensitive to the influence of cold: their efficacy is only affected when the application solution freezes [2]. At temperatures below zero, it must always be expected that a frozen disinfectant solution film will form on the surface when an aqueous application solution is used. It can be assumed that the efficacy is seriously limited in such a case.
For BODE/HARTMANN disinfectants, proof of efficacy at low temperatures is only available for surface disinfectants that have also been tested for use in the food sector and are used, for example, for disinfecting refrigerators or cold rooms. The following measures are generally helpful against the temperature-related loss of efficacy of disinfectants: higher concentrations of the respective active ingredient or longer exposure times.
Disinfectants with aldehydes and organic acids as active ingredients:
• at temperatures of about 10 to 15 °C, double the concentration
• at very low temperatures of approx. 1 to 10 °C, triple the concentration
All other surface disinfectants:
Sources:
1 Kramer A und Assadian O (Hrsg.) Wallhäußers Praxis der Sterilisation, Desinfektion, Antiseptik und Konservierung. 2008, S. 169.
2 Rheinbaben F.v. und Werner S (2014) Desinfektionsmittel – Einflussfaktoren auf die Wirksamkeit. Dialyse aktuell 18(3): 138-147.
