I’ve been known to imbibe now and again. I like to have fun. Those that know me well may have been involved in one or two of my escapades and a few of you may have heard some stories. I am happy to say I have never been arrested and never been hospitalized. Being grounded while a teenager…..well that’s another story!
Why the discussion of alcohol? Alcohol is one of those “magical” chemicals – you can drink it, you can cook with it, you can wash your hands with it, you can clean with it, you can kill with it and you can use it for fuel (it’s also lights nicely with a match!). In the chemical world, there are a number of different types of alcohols that can be used as a solvent (helps to dissolve things) mixed in with other chemistries (e.g. Quats) that can be used as a disinfectant. On its own (aka 70% IPA), we use it as a disinfectant for skin prep and in microbiology, use it as a fixative agent. Here in lies the catch.
Alcohol is a fixative. It’s well known to be one, but generally speaking most do not realize what that means or how its ability to adhere organic matter to a surface can impede cleaning and disinfection. In fact, a study published in AJIC recently looked at just that. The researchers found that treating contaminated surgical instruments with alcohol and allowing them to dry, increased difficulty in cleaning and could lead to sterilization inefficiency. The rationale of using alcohol in this way is of course for its killing properties to reduce pathogen load prior to cleaning and disinfection or sterilization. The researchers found that yes, the bacterial load was reduced when instruments were wiped or sprayed, but this practice significantly increased the attachment of soil to the instruments which made cleaning these same instruments significantly harder. The long and the short was that the benefit associated with the decreased microbial load was overshadowed by the increased difficulty in cleaning and should be discouraged.
While the study looked at surgical instruments, we need to contemplate that alcohol used for surface disinfection will do the same thing. In surface products, alcohol (IPA, ethanol etc) is often added to boost the efficacy of quats and other disinfectant actives to either enhance efficacy (such as achieve a TB claim) or help to reduce the contact time. Similar to the effect of sticking soils to instruments, the same will happen when using alcohols on surfaces, highlighting the importance of removing soils prior to wiping with an alcohol containing surface disinfectant.
In the end, it’s about finding the balance of what you are looking for in your facility and knowing the advantages and disadvantages of the disinfectant you are looking at. If you know what you’re dealing with, you can implement practices to try and minimize the negative side effects of the product. When it comes to surgical equipment, as cleaning is so vital to ensuring that disinfection or sterilization can occur, I hope you’ll stop the practice of using alcohol to wipe down the instruments prior to cleaning. When it comes to surface products, I hope you also do your research, particularly if you work in a high soil environment!