What compounds count as "soap"?

[ckater]

Been trying to figure this out on my own, now turning to the experts. Thanks in advance for your insight. 

Disinfecting sprays are virtually impossible to purchase; soap and water does the trick for killing coronavirus; but taking a soapy rag to doorknobs is time consuming and messy. QUESTION 1: Does a "multipurpose cleaning spray" count as "soap". Do they contain the necessary components to break down the virus? 

Examples: 

Method multipurpose spray Chemical Compound: D-Glucopyranose Oligomers Decyl Octyl Glycosides Dirt Types: Grease Grime.

JR Watkins cleaner: Water/aqua/eau, propanediol, decyl glucoside, sodium citrate, SD alcohol 40-B, Rosmarinus officinalis (rosemary) leaf oil, citric acid, sodium carbonate, fragrance/parfum, methylisothiazolinone.

Meyers Clean Day: Water, Decyl Glucoside, Polysorbate 20, Betula Alba (Birch) Bark Extract, Citrus Limon (Lemon) Peel Oil, Abies Alba (Fir) Leaf Oil, Cymbopogon Schoenanthus (Lemongrass) Oil, Fragrance, Sodium Citrate, Glycerin, Sodium Methyl 2-Sulfolaurate, Citric Acid, Tetrasodium Glutamate Diacetate, Sodium Sulfate, Peg-5 Cocoate, Methylisothiazolinone, Benzisothiazolinone.

QUESTION 2 - Are there particular compounds to look for that would indicate a multipurpose spray cleaner would function as well as (or like) "soap"? 

QUESTION 3 - Would combining liquid soap and water in a spray bottle work for this purpose? Would it need to be rinsed? (The beauty of multipurpose cleaners is that they need no rinsing.)

[mbdowell]

Hi Cynthia,

Let me try Question No. 3 first and work back-- would combining liquid soap and water in a spray bottle work? Sure it would! It will dissolve grease and anything that is water-soluble, like sugars and salts. That's what detergents do; they release fats and greases particularly from surfaces so that the surfaces can be cleaned. You need to wipe, of course, and then as you say, you should rinse or else you leave a soap film behind and it would feel yucky. Even if there is a soap film, is your surface now disinfected? Yes, if it was infected in the first place. The heads (capsids) of viruses and the cell walls of bacteria contain not just proteins and nucleic acids but fats (lipids) and sugars that can be dissolved or detached from the surface by water and soap, which disinfects because it is a good detergent.

We'll get to what makes a good detergent in a minute, but let me suggest some single-ingredient cleaners that don't need rinsing although they do like to be wiped away. You can use rubbing alcohol (70% isopropyl alcohol in water), which dissolves lipids and sugars on viruses and bacterial walls; that's how it disinfects. Or Windex-- ammonium hydroxide is basic and viral capsids and bacterial walls dissolve at its pH, ~11. Or vinegar; if you use distilled vinegar it's 5-10% acetic acid in water, pH ~3 and cell walls don't like to be that acid so it's a pretty good disinfectant with very little residue.

That brings us to Question 1. I'd say that soap is a good example of a multi-purpose cleaner. There are lots of ingredients, but the ones you want are the ones that disinfect (kill bacteria or viruses) because they are good detergents  (remove fats, sugars and greases).

The ingredients that do that are surfactants. They remove the sharp barrier between water and fats (think beads on waxed paper, then put a little dish soap or alcohol in the water). A surfactant lets fats mix with water; that's why it's a good detergent. Here's Question 2, what to look for on the ingredients label. First look for organic alcohols (name ends in -ol). Isopropyl alcohol or isopropanol has the formula C3H8-OH. The -OH end dissolves in water but the C3H8-  end dissolves in fats and oils. If you add an alcohol to fat and water, the fat will lift off the surface (detergent) and the alcohol will keep fat and water together (surfactant). So look first for alcohol surfactants; they end in -ol. Then look for            "(something)yl (something else)ide" or "(something)yl (something else)ate". Anything like that-- for example, Watkins' decyl glucoside or Meyers' Sodium Methyl-2 Sulfolaurate-- is an ionic surfactant. It has an organic end (decyl, methyl) that doesn't like water and dissolves in oils or fats, and an ionic end (glucoside, sulfolaurate) that dissolves readily in water. Multipurpose cleaners have a lot of ingredients for their different purposes, and formulating a cleaner for a set of purposes is a lot of fun. But if you are just looking for surfactants on the label, look for -ol for alcohol surfactants and -yl with -ate and -ide for ionic surfactants.

Hope this helps!

Mike Dowell  

[speerd]

This is a great video on how soap kills the corona virus:

Can Soap REALLY Kill the Coronavirus? | Reactions Science Videos - American Chemical Society 

[scooke]

GREAT link, Drew!  To others interested in helping with PSAs, there is another recent video (Apr20) there about mask efficiency, use, and homemade applications.  Watch them and share them on your social media!