04-24-2020, 10:40 PM
d4 wrote:
[quote=neophyte]
It's a complex interplay of lipid bilayer intercalating/disrupting ability versus persistence. Alcohol sanitizers (above 70% alcohol concentrations) will immediately disrupt the integrity of the viral (or bacterial) lipid bilayers and thus disrupt the presentation of lipid bilayer-imbedded proteins responsible for attachment to cells and subsequent infection (or in the case of bacteria - disrupt cellular integrity and internal structures and allow leakage of vital internal fluids and ions). Then the alcohol evaporates, and carries away the water in the bacteria or virus, thus dessicating them.
Quaternary ammonium compounds, like myristalkonium chloride in Barbacide, act the same way, but are at much lower concentration in the solvent (water), and thus take longer to build up to an effective level in the lipid bilayer. Hence the instruction to allow adequate time, without rinsing, to insure the full germicidal effect. As the solvent evaporates, the effective concentration rises, as does the germicidal activity.
In general, quaternary ammonium compounds are quite stable in water. For example, Lysol has a shelf life of about 2 years, although it has other ingredients that may protect it from contamination with microbes after it is opened. I think it is that contamination that reduces germicidal effectiveness over time, rather than chemical instability of the active ingredient.
So in a nutshell:
(If I'm reading this correctly)
Alcohol based consumer household cleaners like Lysol and Clorox are the best. The inclusion of alcohol along with the chemicals has an immediate effect.
Barbacide and Steramine do not contain alcohol so they are second best. And need to "soak" on the surface for a few minutes before wiping for it to have full effect.
The information is great if you have a choice of products. I haven't seen Lysol or Clorox on store shelves for over a month, so i don't really have a choice. Barbacide and Steramine is "better than nothing!"
Sorry, no. Firstly, as Robert M points out, the manufacturer provides the best guidance for their particular product. My statements about the efficacy of alcohol refer only to solutions having 70% or more alcohol (short chain: 2 or 3 carbons only, ie ethanol or propanol) . Neither Lysol nor Clorox have these alcohols. Lysol's main germicidal effect is due to its "quat" chlorides and long chain derivatized alcohols, each of which can disrupt lipid bilayer membranes but are present at only 10% or so in undiluted Lysol. Thus it takes a little time for these ingredients to partition out of the water and into the lipid bilayers at a level high enough to be germicidal. Clorox bleach is an oxidizing agent whose effect is time dependent as well, with higher concentrations requiring much less time to kill germs. But bleach is volatile and can cause body damage if you breathe its fumes, requires much rinsing to remove from your skin, and is generally all around a pain in the tuchus to use.