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Thursday, July 11, 2013

A lamp hot enough to melt polymer banknotes?

Resting on top of my bedside reading lamp, a polymer banknote was unaffected.

A London woman told The London Free Press that she placed an envelope, containing a number of hundred dollars bills, beneath a common table lamp. On returning a few hours later, she discovered the heat from the lamp had shriveled her polymer currency.

The paper missed the story. The shriveled bills are not the story; The bills are the evidence — evidence of a seriously defective and incredibly dangerous table lamp.

What company makes such a monster and how many watts is the light bulb? Is an old incandescent bulb screwed into the brute? This lamp is clearly a fire hazard as polymer bills reportedly require about 140-degrees Centigrade (284-degree Fahrenheit) to suffer heat damage. Don't believe me? Read what the Bank of Canada says about what they call the urban myth concerning melting notes.

Even if the Canadian government is overstating the temperature at which damage occurs, one can suffer a serious burn touching a hot surface at 90-degrees Centigrade for as short a time as half a second.

These bills surely reached a temperature higher than 90-degrees Centigrade to suffer so much damage. This lamp clearly poses a real danger to this woman and her family. In fact, The Bank of England has proven that even a temperature of 100-degrees Centigrade fails to cause any damage even after subjecting notes to this high temperature for a full hour.

This is not the first story about Canada's melting currency. A year ago newspapers across Canada carried a story based partially on anecdotal tales repeated by Brittney Halldorson, a teller at the Interior Savings Credit Union in Kelowna, B.C., claiming the polymer bills were melting and melding together.

When I was a photographer with The London Free Press, I hated stories like this one. I would have wanted to take an oven thermometre with me to take a reading of the temperature below the lamp. (Surely the lady did not sit the bills right on the hot, light bulb. A hundred watt light bulb can reach a temperature in the range of 475 degrees Fahrenheit on the surface of the glass. If you don't believe me, check the book Kirk's Fire Investigation.)

Sadly, stories like this almost write themselves. The reporter could write the lede before even meeting the lady with the crinkled, shrunken currency. The LFP reporter wrote: "This isn’t money burning a hole in your pocket — it’s money simply burning up." I'm sure the angle of the story was set before the reporter, Kate Dubinski, even left the office. I doubt Kate inspected the lamp in question.

Despite the problems the London woman has had with polymer banknotes and an unbelievably hot table lamp, the new Canadian notes should last about four times as long in circulation as the traditional paper bills being removed from daily use. The new $5s and $10s will be released later this year.

The four times figure is based on Australia's experience with plastic bills. In New Zealand, the lifetime factor increase ranged from 4.5 to 7.3 depending on the denomination. The Bank of Canada’s assumption of a 2.5 factor is conservative.

Of course, all bets are off if you leave your plastic money under Super Lamp, a lamp so hot it's the stuff of urban legends.

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Two British Standards address hazards of hot, touchable surfaces. The British Standard EN 563 (1994), Safety of machinery – Temperatures of Touchable Surfaces – Ergonomics Data to Establish Temperature Limit Values for Hot Surfaces states that the burn threshold for contacting glass for a time of 0.5 seconds is between 183.2º F and 194º F (84º C to 90º C).

Snopes calls tales of melting Canadian money an urban legend. Their reporter agrees with the Bank of Canada.

For Search Engines: file under Melting Polymer Banknote M

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