杏吧原创

Mystery stench explained

The vexed question of why some brand-new carpets smell of cat urine, even in feline-free households, has been answered.

Last year, a carpet manufacturer approached Jodi Martin of the Calgon Corporation in Pittsburgh, saying that customers were complaining that their new carpets smelled of cat urine. 鈥淚t鈥檚 something that pops up occasionally,鈥� says Ken McIntosh of the Carpet and Rug Institute in Dalton, Georgia. Carpets are sometimes returned to stores because customers suspect that animals have infiltrated the sales warehouse and left behind unwelcome deposits.

Martin obtained samples of carpet, some with and some without the offending odour. But she and her colleagues couldn鈥檛 find any chemicals that were used during the manufacture of the carpets that would account for the smell, so they isolated bacteria from the samples and identified the organisms present using gas chromatography.

The team found that all of the foul-smelling samples of carpet contained large quantities of anaerobic bacteria that emit a chemical called butyric acid.

Many people feel that butyric acid has a stench reminiscent of urine, says Martin, who presented her research this week at a meeting of the American Society for Microbiology in Los Angeles.

The bacteria are probably introduced into the carpet during manufacture and it will take time to figure out how to prevent this, says Martin. But she thinks they鈥檝e found the culprits.

From New 杏吧原创, 27 May 2000