Friday, January 16, 2009

Think Before You Flush: Investigating Toilet Handles

New toilet handles around campus claim to protect against germs. Do they? Find out after the jump.


Earlier this semester, my suitemate Christel Chehoud '11, mentioned that while she was at a precept, the boys commented that they were annoyed with the new UPPERCUT™ Dual-Flush toilets installed all across the University because they urinate standing up. The boys said they found it inconvenient because the new toilets instruct users to flush upward for liquid waste and downward for solid waste which is difficult because they use their feet to flush the toilet. This led her to wonder how clean the toilet handles really were, considering the sign from Sloan company says the handles have a "protective coating" which protects against germs.


We decided to investigate and we obtained 4 petri dishes from her lab and leaving one as the control, we swabbed 3 different toilet handles - two from a bathroom in 1981 Hall, Whitman College and one toilet which was not a dual-flush toilet in Rockefeller College for comparison. We left one petri dish untouched/the control so that you could see the difference.

We left the dishes in a cool, dark environment and after a few days found that protective coating doesn't make it "germ-free". One of the dishes showed signs of mold and of course it smelled horrible (but that's how bacteria is supposed to smell). The two with the protective coating fared better than the dish from Rocky, which was the worst offender, but still -- false advertising?

From Left: Handle from a stall in 1981 hall, Whitman College, Princeton University. (The clear dish on top was our control.), another stall in 1981 Hall, and lastly a non-dual-flush toilet handle in Rockefeller College.

When I contacted the Sloan Valve Company regarding the matter, a spokesman said "While the handle may be coated with a proprietary polymer layer that inhibits microbial growth, it does not prevent or eliminate such organisms." He suggested that cleaning products used on the handles could be impacting the surface of the handles.

He added that the "Princeton men angry about the 'Up' flush" should stop kicking because it could damage plumbing and cause leaks.

Yale, University of California, Santa Barbara and Purdue University have also installed dual-flush toilets, which according to the company's website
saves approximately a gallon of water per flush.

--Tasnim Shamma '11

4 comments:

Peter W. said...

Nice work, guys!

kungming2 said...

It says "protects against germs," not germ-free. Completely different, as the first just implies less germs than a regular handle.

Tasnim Shamma '11 said...

But it shouldn't have mold if it's claiming to protect against germs. They almost did as bad as the handle from Rocky.

Anonymous said...

Hello. And Bye.