as an antiseptic, 70 percent of alcohol is prefered to a stonger solution. Pure alcohol coagulates protein in contact. Suppose the pure alcohol is poured ovr a single celled organism. Th alcohol will penetrate the cell wall of the organism in all direction, coagulating the protein just inside the cell wall. the ring of the coagulated protein would then prevent the alcohol from penetrating farther from the cell, and no more coagulation woul take place. At this time the cell would become dormant butnot dead. under the proper condition the cell would then begin to function. if 70 percent of alcohol is poured to a single celled organism, the diluted alcohol also coagulates the protein, but at a slower rate, so that it penetrates all the way through the cell before coagulation can block it. then all the cell is coagulated and the organism dies.
The percentages refer to the relative amount of alcohol as compared to the amount of water. 70% alcohol is 30% water. 91% alcohol is 9% water. Which is a better disinfectant depends somewhat on how it is used, but 70% alcohol will tend to disinfect much more effectively than 90%+ alcohol. This is particularly true for the disinfection of surfaces, including human skin.
This may seem counter-intuitive, but the reason has to do in part with the fact that alcohol evaporates much more quickly than water. With the 70% solution, evaporation tends to be slower (due to higher water content), and therefore the alcohol will have more time to kill microorganisms. In other words, the 91% solution has a higher tendency to evaporate before all susceptible microorganisms are killed. This is the primary reason that 70% alcohol tends to be a more effective disinfectant for surfaces than 90-91% alcohol.
The 70% solution also helps to ensure that the alcohol enters the cells of microorganisms, rather than just rapidly disrupting the cell walls and doing nothing further, which is what tends to happen with 90%+ alcohol solutions.
Also, the greater relative concentration of water in the 70% alcohol solution means that more proteins--and more types of proteins--in microorganism cells will be denatured (i.e. destroyed). This is because water plays an important role in the destruction of proteins.
This should not be taken to mean that 91% alcohol is not an effective disinfectant; it is. But for maximum efficacy, I would recommend 70% alcohol. If disinfection is a primary concern, you definitely do not want to go above 91%, in any case.
So as we can see, one should not simply see the bigger number and make assumptions based on that.
Seventy percent isopropyl alcohol is the most effective concentration for killing microbes. Lower concentrations are not strong enough, and higher concentrations evaporate too quickly.
Too high of an alcohol content tends to preserve microorgs instead of killing them (or so I've been told, but can't remember the logic behind it).
This is a solution containg 60 percent isopropyl alcohol; can be used as rubbing alcohol.
iso HEET is 99% isopropyl alcohol
iso HEET is 99% isopropyl alcohol
No. Grain alcohol is ethyl alcohol. Isopropyl alcohol is a different compound and is not safe to drink.
Yes, it is.
Hydrogen peroxide 3% is a much better disinfectant. Hydrogen peroxide may be used in the oral cavity for disinfection. Isopropyl alcohol, also known as Rubbing Alcohol is only used on surface skin and not on mucosa. It dries quickly by evaporation, hence it does not have too much contact time to completely disinfect. Hydorgen peroxide's foaming action ensures full coverage of an area, with extended disinfecting action.
add water
by using fractional distillation
70%
The weight will depend on how much of the substance there is.
It is difficult and expensive to refine anything to 100% purity. Best to use 70% as it is just as effective and cost a whole lot less.
Wieland said Lysol disinfectant spray contains about 80 percent ethyl alcohol, compared with 40 percent to 50 percent in most whiskeys.