Hi Jill,

Waterless urinals are great. But they need to be from the right manufacturer and their recommended maintenance regimes must be followed. Please go back to that manufacturer and tell them that this advice was silly: "I have been told by manufacturers to place vegetable oil into the traps to contain odours". You can't just convert any old urinal into a waterless urinal just by adding some vegetable oil!

There are two ways of odour traps in proper waterless urinals: either with a blocking fluid (= the example that Patrick gave in the post before this one) or a silicone curtain membrane (my personal preference). Both require maintenance. If that is neglected, it can start smelling.

The wikipedia article on urinals has a pretty good section on waterless urinals, see here:
en.wikipedia.org/wiki/Urinal#Waterless_urinals
The last two photos in the photo gallery of that section (and some of the text and references) were added by me. I used to dabble a fair bit with waterless urinals. They are all over the place in Germany nowadays.

So your university needn't have replaced their waterless urinals with flush urinals unless they picked the wrong manufacturer to start with. More likely, they just didn't have a good maintenance routine.

Regards,
Elisabeth

Hi Jill,

Odour from a urinal comes from two places; the sewer and the fitting itself. Using a flush urinal the urinal is rinsed with water periodically to remove urine and there is a water barrier ( u bend) between your nose and the sewer that is replenish with clean water each time the urinal is flushed. This is how the smells are avoided.
Most Waterless urinals ( and i must say here that i am a dealer for one brand ( www.toiletrevolution.com/waterless-urinals/) use an oil based trap to prevent sewer odours but the trap has been redesigned so it is not simply a case of adding oil to a traditional U Bend because the urine would flush the oil through and leave a “trap” of urine that would smell. The second smell issue is that with all waterless urinals the fitting needs to be cleaned down with a proprietary fluid that is compatible with the oil based trap. When this is done there are no issues with smells and they are installed all over the world. 👍

I have been told by manufacturers to place vegetable oil into the traps to contain odours, but in practice I have witnessed that this method still doesn't eliminate odours.
One building at my university converted all waterless urinals to water flushing ones because of the constant odour issue.

Oh...I did not. Will check it.
Thank you.

I'm just wondering if you have browsed through the existing threads in this sub-category on urinals because the various options have been discussed there: forum.susana.org/172-urinals

Regards,
Elisabeth

To properly trap urine odours from urinals(waterless) what would you suggest to be used?