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What are Urinal Cakes?

They may be a mystery to the ladies, but they’re very familiar to gentlemen. They’re called “urinal cakes” and are commonly seen at the bottom of urinals. Their purpose? Control bacteria and reduce smell.

They may be a mystery to the ladies, but they’re very familiar to gentlemen. They’re called “urinal cakes” and are commonly seen at the bottom of urinals. Their purpose? Control bacteria and reduce smell.  They’re made of para-dichlorobenzene, a chemical that does deodorize but comes with baggage.  The solid cake sublimes, meaning it converts to a gas without going through the liquid state.  It is a recognized animal carcinogen and causes concern because it can be found in the blood of most people.  Not all of it comes from urinals of course.  Dichlorobenzene is used as an insecticide and moth repellant and is found in many air-freshners.  It would not be a bad idea to phase it out from urinal cakes.  So here’s another question to consider.  Should you or should you not pee on the urinal cake?  In theory the warm urine will vaporize more dichlorobenzene putting the peeer at greater risk.  Supposedly the reason we refer to these ites as “cakes” traces back to Benjamin Franklin.  While experimenting with the Franklin stove he baked a bunch of cookies that he eventually placed beside the outhouse for his guests.  Apparently John Hancock accidentally knocked the plate into the urine pot, and presto, the cakes absorbed the smell.  At least so goes the story.

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