Does salt kill bacteria?

In this brief guide, we will answer the question “Does salt kill bacteria?” and discuss why salt is used as a preservative. We will also discuss whether putting salt on a canker sore helps.

Does salt kill bacteria?

Yes, salt can kill bacteria. Salt draws out water from bacteria and dehydrates them. The dehydration obviously kills them. So when there is no bacteria left to damage cells, healing is promoted.

Salt has been used as a disinfection for a long time. Salt helps disinfect the wounds and promotes healing. What happens is salt robs the injured cells of their water by osmosis. The dehydration makes it very hard for bacteria to survive in it.

Although salt can disinfect, it is only a temporary fix. You should go see a doctor for more serious wounds as salt can kill most of the bacteria, but not all.

Moreover, saline water is used to clean the wounds rather than salt in its crystalline form as first of all salt can sting, and secondly the salt crystals can be harsh for the skin.

Why is salt used as a preservative?

Salt is used as a preservative due to its hygroscopic nature and also because it is toxic to microorganisms. It is widely used to cure meat because when it is applied to meat, it absorbs the moisture from the meat leaving it dry and dehydrated. 

This dehydration leaves the meat less susceptible to contamination by bacteria. Dehydrated meat does not serve as a favorable condition for the survival of bacteria.

In addition, bacteria will get robbed off any water present inside its cells due to the presence of salt outside, again due to osmosis. So this is why salt has been used for years now as a natural preservative.

Does putting salt on a canker sore help?

Yes, putting salt on a canker sore helps but it can be very painful so it is better to put salt in warm water and then use it to rinse your mouth. 

Salt increases the pH of the canker sore and makes it more alkaline. Bacteria need acidic conditions to grow, it is hard for them to survive in alkaline conditions. 

Warm up some water in the microwave in a cup and dissolve some salt in it. Rinse your mouth with it and keep it in your mouth for 15 to 30 seconds then spit it out. Repeat it every couple of hours.

Keep in mind that it will sting.

Find out more ways to get rid of canker sores here.

Does salt have calories?

No, salt does not have any calories at all. If you add it to your food, the total calorie count of your food would not increase because of salt. 

Can salt make you gain weight?

Yes, salt can make you gain weight but only water weight. Salt directly does not have any effect on weight gain but what it does is, when you take a lot of salt, your body makes you feel thirsty so that you drink water and everything stays balanced. 

When you do drink water, your body holds onto that water. So this water retention is what can make you gain weight. 

Does salt have an expiration date?

No pure salt does not have an expiration date but table salt does come with a ‘best before’ date. Salt is a natural preservative. Pure salt  (NaCl) does not go bad. Salt generally lacks moisture which makes it very hard for bacteria to survive on it.

However, table salt that has other chemicals added to it may go bad. The salt itself does not go bad, but the chemical may go bad. One example of these chemicals is iodine which is added to salt to prevent goiter, a thyroid disease. 

This is why table salt comes with the best before date. It still does not mean that the salt will be harmful if used. Instead the chemicals may just not provide the benefits that they were meant to provide.

Other FAQs about Salt that you may be interested in.

Does salt evaporate with water?

Does salt have a smell?

Does salt have an expiration date?


In this brief guide, we answered the question “Does salt kill bacteria?” and discussed why salt is used as a preservative. We also discussed whether putting salt on a canker sore helps.


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