why do nurses and physicians use 70% alcohol to wipe the skin up to that time giving an injection?

why do nurses and physicians use 70% alcohol to wipe the skin up to that time giving an injection?
Alcohol sterilises the site of injection. It is cheap.
In order to prevent infections form occuring. If you would inject those without first cleanign the nouns, it is possible that bacteria or other substances from the skin's surface may be pushed into the interior of the body beside the needle, so they try to prevent this by swabbing the nouns with alcohol. The alcohol doesnt capture rid of the bacteris, but it effectually kills them, which finances that they wont be able to replicate once contained by the body.
Hope this helps
70 percent alcohol is bactericidal.wipe the skin removes the bacteria from the skin and prevents microbes being injected into the tissues
This is the most bacteriocidal percentage.
To shrink the number of bacteria on the skin that could bring back transported inside the body by the needle.
To sterilise the site of injection and thus prevent infection, when the skin is punctured.
I've other found it very interesting that they swab the site on the arm of a being who is sentenced to die by leathal injection. Infection is the least of their worries.
Alcohol sterilises the skin. Your skin is extremely dirty even though you take showers. There is so much on your skin you don't know roughly speaking. If something is going in your body it have to be clean. Also doctors don't want you to carry a infection from the needle.
In charge to prevent infections due to bacteria on the injection site.