The efficiency of a disinfecting agent depends on its molecules, the type of surface to be treated and how it is applied. Therefore, choosing the perfect agent implies knowing first your disinfection goals.
Some disinfectants and their characterstics :
- Chlorine compounds : Chlorine compounds act by oxidating micoorganisms' cell membranes. The main downside with the use of Chlorine compounds is that they are corrosive. We must therefore limit their concentrations. The best known Chlorine compound is the Bleach or Sodium Hypochlorite. Yet, the lifetime of the Chlorine compounds is limited and they usually lose their effectiveness.
- Aldehydes : Aldehydes denatures proteins and the nucleic acids of microorganisms. The most frequently used molecules are the Formaldehyde and the Glutaraldehyde. When they reach a high concentration in the air, they cause reactions in respiratory, skin and mucous membranes. Formaldehyde is considered as a carcinogen since January, the 1st 2007.
- Quaternary ammonium compounds : Their uses cause a disruption of plasma membrane and a leakage of cell components, leading to a cellular lysis. They have the advantage of being non-corrosive in the near-neutral pH. As they are surface active compounds, they are mostly foam which limits their use.
- Peracetic acid : Acetic acid and hydrogen peroxide-based, it has an oxidizing action on the molecular bonds leading to the destruction of the cells. It is not corrosive for metals if it has been diluted in distilled or reverse osmosis water . However, it is very corrosive with chlorinated water.
- Biguanides : They alter the permeability of the microorganisms' cell membranes. The Chlorhexidine is the best known and it is often used as an antiseptic. Biguanides' advantages is their little toxicity and non-corrosivity.
- Alcohols : Ethanol and Isopropanol are the most frequently used. Their action requires the presence of water with an optimal concentration of 70%. They have the advantages of beeing "self-drying" and having no effect on most surfaces. However, they can lead to clouding on acrylate surfaces (Plexiglas...).
- Chlorine Dioxide : It has an action on the transport of nutrients across the cell wall. This oxidant is as effective as Chlorine compounds, with a higher spectrum efficiency and the possibilty of destrying biofilms.
|Quaternary Ammonium compounds||+++||+++||++|
|Aluminium Alloys||Phosphoric acid|
|Aluminium Alloys||Alkaline pH > 12|