Expert: Dana Krempels, Ph.D. - 12/7/2009

Question
QUESTION: Is human urine sterile?  Is human urine sterile after it leaves the body months later? What are the health issues in babies or adults if unsterile urine is ingested?

ANSWER: Dear Jaime,

Human urine is sterile while in the bladder, as long as there is no urinary tract infection.  Once it exits the bladder, however, and leaves the urethra (which usually contains resident bacteria), it can be contaminated by bacteria on the outside of the body and in the environment.  

Once there is bacteria in the urine, it's no longer sterile (by definition).  And it doesn't take long for the urine to start to decompose through the action of these bacteria, unless it is sterilized and/or refrigerated.

Ingestion of non-sterile urine may or may not cause problems.  But many environmental bacteria are destroyed by the enzymes in the mouth and stomach, and will not survive the trip to the intestine unless they are very numerous in the sample ingested (more likely that some will survive).  And the exact nature of the upset will depend on what bacteria have taken up residence in the urine.  I would think that the most likely result would be an intestinal upset, which could be severe if really nasty bacteria were growing in the urine.  But there are many different possibilities.

If you are concerned about this, please consult your physician to make sure no treatment is necessary for a person who has (accidentally, I hope!) ingested old, non-sterile urine.

Dana



---------- FOLLOW-UP ----------

QUESTION: My baby could POSSIBLY be exposed to this in his fathers home and am just looking for the answers.  My babies health is my first priority.  You know babies, they suck on everything or put everything in their mouth.  If a baby were to suck on nonsterile, aged urine, are there any other health conserns like organ/respitory development (other than the fact it is gross).  ANY other advice is appreciated.

Answer
Dear Jaime,

I would suggest that you take this issue up with the father:  old urine in the house suggests that this might not be the only hygiene problem, and this doesn't sound like a healthy environment for a young baby.  Decaying urine also exudes ammonia fumes, which can be harmful and irritating to the lungs.

The urine itself might not be deadly.  But it's certainly not hygienic, and I would not want any infant of mine to be wandering around in a place where s/he could ingest things contaminated with old, bacteria-laden urine.  Yuck!

I hope this helps.

Dana