Hydrogen peroxide was first discovered in 1818, but its use as an odour counteractant or disinfectant didn’t begin until 1891. Still, that makes it one of the oldest known disinfectant chemistries. Hydrogen peroxide generates hydroxyl radicals – the strongest known oxidant – which attack DNA, membrane lipids, enzymes and other vital cell components to exhibit its germicidal kill. The end result is hydrogen peroxide’s broad spectrum of potential germicidal activity. Depending upon its concentration, hydrogen peroxide can be used for applications ranging from use as a preservative to that of a chemical sterilant. At 25ppm, hydrogen peroxide can inhibit growth of bacteria, while 6% hydrogen peroxide can inactivate bacterial spores – the toughest known microorganisms. Hydrogen peroxide can also inactivate viruses (both enveloped, non-enveloped), fungi, and mycobacteria.
Believe it or not, hydrogen peroxide also naturally exists in honey and milk as a preservative. It is available in our saliva as an oxidant, in blood as a part of our immune system against pathogenic microorganisms, and in tissues due to cellular metabolism.
When applied to a surface or item, hydrogen peroxide does not carry any residual activity since it either evaporates from the surface or degrades into its constituent components – water and oxygen. Furthermore, because it has more than one target site while inactivating microorganisms the potential for bacterial resistance to develop against hydrogen peroxide is essentially non-existent.
The fact that hydrogen peroxide degrades into water and oxygen also makes it an environmentally preferable disinfectant chemistry.
As we have dwelled upon in previous blogs, another very important consideration is a product’s ability to clean and aid in the ability to lift and remove soils from a surface. Since hydrogen peroxide is an oxidizing agent, it oxidizes organic materials allowing them to be more easily removed from the surface. For this reason hydrogen peroxide is used in many commercial and consumer cleaning products.
With these key points fresh in your mind, how would you grade standard hydrogen peroxide as a disinfectant chemistry?
Similar to chlorine based solutions, hydrogen peroxide solutions are utilized within a spectrum of various concentrations. Taking this into account, here’s how we would score stand-alone hydrogen peroxide solutions on the key decision making criteria:
Speed of Disinfection – B to C
- High concentrations of hydrogen peroxide (6-7%) do carry relatively rapid contact times for the high level disinfection and/or chemical sterilization of medical instruments- For surface disinfectant applications, standard hydrogen peroxide solutions tend to be quite slow.
Spectrum of Kill – A to C
- Similar to the speed of disinfection, performance in this criteria is tied to the in-use concentration- 6-7% concentrations can be used as chemical sterilants to eradicate all microbial life; 3% solutions may be used as surface disinfectants or skin antispetics
Cleaning Effectiveness – B
- Hydrogen peroxide oxidizes organic materials allowing them to be more easily removed from the surface. For this reason hydrogen peroxide is used in many commercial and consumer cleaning products.
Safety Profile – A to B
- This is another parameter largely affected by the in-use concentration of the solution- Hydrogen peroxide based solutions tend to be safer alternatives to other commercially available disinfectant chemistries
- Concentrations used for surface applications tend to be non-toxic and non-irritating; concentrations used for medical device disinfection, although irritating to eyes and skin, do not carry respiratory irritation profiles as do many disinfectants used in these applications
Environmental Profile – A
Cost Effectiveness – B
- Hydrogen peroxide is readily available from various manufacturers and can be found in both concentrated and ready-to-use formats.
**For more in-depth scientific information about Hydrogen Peroxide and other disinfectant chemistries, stay tuned to www.infectionpreventionresource.com
Hasta la vista
Lee – The Germinator