No word on the smell . . .

I was taken aback (sort of) by reading about a new technique for producing bricks . . . using human urine.

The world’s first ‘bio-brick’ made from human urine was unveiled by University of Cape Town (UCT) civil engineering masters student Suzanne Lambert on Wednesday.

. . .

Dr Dyllon Randall, Lambert’s supervisor and senior lecturer in water quality at UCT, explained that the “bio brick” is created through a natural process called microbial carbonate precipitation.

“It’s not unlike the way seashells are formed,” Randall said.

Parts of the urine are combined with loose sand and a bacteria to produce an enzyme called urease which breaks down the urine to produce calcium carbonate through a complex chemical reaction.

The calcium carbonate turns the sand into “cement”. The bricks are made in moulds at room temperature – better for the environment, as regular bricks are kiln-fired at temperatures around 1 400°C and produce vast quantities of carbon dioxide.

The strength of the bio-bricks would depend on client needs.

“If a client wanted a brick stronger than a 40% limestone brick, you would allow the bacteria to make the solid stronger by ‘growing’ it for longer,” said Randall.

There’s more at the link.

I daresay this process might have all sorts of useful applications in areas where bricks are hard to come by and/or make . . . but I can’t help feeling a bit queasy about the process.  How are you going to go about collecting the urine?  Shared urinals draining into a barrel?  If you can’t flush them, that’s going to get a bit aromatic after a while.  The article also points out that men might have an easier time “donating” urine than women, particularly where tribal taboos predominate (which, in Africa, is a large part of the continent).  And what about “number two”?  It’s going to be hard, if not impossible, to separate “number one” from the solids involved.  Can animal urine also be used?  If so, how to collect it?

Still, those are just details.  If the new process works, and it’s cheaper and easier than current technology, there’s sure to be interest in it.  I just hope the odor of urine doesn’t carry over to the bricks – or the houses built with them!



  1. That may compete with DEF as well. Diesel Exhaust Fluid is derived from cow urine as I remember.

    I wonder why people hate plants so much that they would try and limit what they breathe? I mean, co2 is plant food…

  2. People in the Middle East are still making useful bricks by mixing clay, straw, and water, and setting molds in the sun to dry for a day or two. Adding a little sheep dung apparently makes them a bit stronger, although much more aromatic.

  3. In pre-industrial Europe, many kept a covered bucket next to the privy to collect urine, which over time, became a weak bleach. This would be used for laundry purposes. When you consider they laundered every month or so, you always had some bleach on hand, so to speak. Also, our noses are far more dainty when compared to our ancestors. They often lived in one room houses with their farm animals, in a sort of communal barn. Life could be much worse, and often was.

  4. I think I read somewhere that in ancient Rome, leather tanneries kept a large amphora outside for passers-by to urinate into. Apparently it was used in tanning leather. And Alaska natives use a mixture of urine & moose brains to cure moose hide.

  5. It's only in the modern age that we think that flushing away a small amount of urine with two or more gallons of potable water is a good idea.

  6. stencil has the germ of a good idea….

    You could have "Premium Brand" weewee!! Aspargus is a good starter, but I'm sure there are other ingredients which could "enhance" the product.

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