What is the difference between distilled water and sterile water?

Answer 1

V. BARATHI

Chennai

Distilled water and sterile water are totally different. Water in pristine form, (as in the rain water or water obtained from snow) is called pure water. When water is taken from other sources (that is other than rain water) it may contain salts and other dissolved solids and this is therefore impure water.

To remove these salts or other dissolved solid etc from the impure water the process of distillation is used. Distillation is a process in which water is boiled and heated till it evaporates and the evaporated vapour is cooled, thereby condenses to form water again. This processed water is called distilled water.

Uses of distilled water are for working, cleaning of sensitive chemical plants, machines etc, and in preparation of chemical solutions where pathogens, microorganisms are not of concern. It be noted that distilled water is pure water free from other chemicals etc but is not sterile.

Sterile water is that which inhibits the growth of microorganisms. Since in nature there are a variety of microorganisms which withstand and survive heat treatment even beyond 100{+0}C, these temperature resistant organisms resist and survive after the process of distillation.

Thus the distilled water though pure, is not sterile water. So further processing of distilled water is done to make this water sterile. This is done by autoclaving the distilled water where due to increased pressure in the autoclave (as happens in domestic pressure cooker) the temperature is raised much beyond 100{+0}C due to which the high temperature resistive microorganisms called pyrogens get destroyed, rendering the distilled water sterile.

Thus, the difference between distilled water and sterile water is that whereas distilled water is not free from microorganisms and may permit their growth, sterile water is totally free from microorganisms .No organic growth is possible in this. It is this sterile water which is used for injections and parentaral preparations in pharmacy.

SOM SHANKAR

Assistant Professor of Engineering Chemistry

GITAM University

Visakhapatnam, Andhra Pradesh

Answer 2

Sterile water is clean water without any other chemicals added. Sterile Saline is a solution of 0.9% Sodium Chloride used for would irrigation and cleaning.

Both are used for cleaning wounds. Lets take a look at some advantages and disadvantages of both of them:

0.9% Sodium Chloride Saline is the traditional antiseptic and wound cleansing solution used today in hospitals. Whilst it has minimal healing properties, it does not have any detrimental properties either.

Water has been used for centuries as a cleaning solution for wounds. However, water causes wounds to 'weep' resulting in more frequent dressing change. This can be very inconvenient and if it is neglected it can cause infection.

Therefore I think that Saline Solution is the better choice for cleaning wounds.