A Scratch-and-Sniff Story

"Responsible thing: An energy company sending out scratch-and-sniff cards that smell like natural gas so customers can learn to identify the smell in case of a leak. Unfortunate thing: An entire box of said cards compressed in a garbage truck that then travels through town and makes residents think there’s a widespread gas leak." -- from The Consumerist, 5/8/13

 A gas company employee in Great Falls, Montana, threw away the scratch-and-sniffs because they were expired, but when the garbage truck's compressor processed them, it was like "turning the compressor into a giant finger that scratched all those smelly cards."

"Gas on all floors" -- Paris sign that inspired Marcel Duchamp
See this blog post for details

What people really smelled was a harmless but smelly gas called mercaptan, which gas companies for a long time have added to harmful but odorless natural gas to make sure people can smell it when it leaks.  (The practice started after a build-up of the undetectable gas caused a tragic school explosion in 1937.)

Whether they had been educated by one of the scratch-and-sniffs or otherwise learned to recognize a gas leak, the people in Great Falls recognized the smell so -- "Emergency crews responded to reports of gas smells and evacuated at least six downtown buildings," according to the Great Falls Tribune.

I was surprised that anyone thought it was necessary to ensure that people could recognize the smell of natural gas. I thought the smell was absolutely universal in America where so many homes have a gas line, and occasional bits of odor escape from time to time without consequences -- other than maybe a call to the gas company to check for leaks.  When a person totally loses the sense of smell, a condition called anosmia, the fear of missing a gas leak is one of many terrible reactions to the loss.

My own false alarms about a gas smell have resulted when my hands have absorbed the stinky aroma of garlic during food preparation. Sometimes the odor stays on my hands until the middle of the night, when it's made me think of mercaptan, a thiol (organo-sulfide) with a garlic-like odor. I've talked to other garlic-loving cooks who have experienced this.

A lot of stinky organic chemicals can cause a similar odor. For example, it can also result from algae in seaside ponds. Last May in Santa Barbara I wondered why the beautiful ponds of the Andree Clark Wildlife Refuge near the downtown beaches were absolutely rank-smelling. The rotten-egg-like odor, according to the Santa Barbara Independent, came from an unnatural algae bloom, which arises from time to time in the artificial pond which replaced a natural wetland.

I imagine that everyone has a memory of a gas-leak smell that wasn't a gas leak, but I guess Great Falls is the champion!