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Loss Of A Printed Icon, Methylimidazole-Lite Cola

by Stephen K. Ritter
May 1, 2012 | A version of this story appeared in Volume 90, Issue 14


Credit: Encyclopaedia Britannica
Dinosaur volumes: They still look good on a bookshelf.
The 2010 edition, the last to be printed.
Credit: Encyclopaedia Britannica
Dinosaur volumes: They still look good on a bookshelf.

Once upon a time, it was a happy day in the lives of many Americans when an Encyclopaedia Britannica salesman’s shadow graced the front door. If the monthly payments were affordable, a set of the encyclopedias would join the family station wagon and television set as status symbols. But now, after 244 years, the venerable Encyclopaedia Britannica is going out of print, a victim of the digital age.

First published in Scotland in 1768, the encyclopedia going forward will be available only online. This occurrence might stir up some feelings of lament among Newscripts readers.

This Newscripter, for example, grew up leafing through the 1967 edition. Pulling one of the heavy alphabetical volumes off the shelf, I could look up biographies of writers or war heroes, or check out topics in science. The entry on chemistry spans more than 50 pages—it even mentions C&EN.

But now that Wikipedia and other Internet tools are available, the printed Encyclopaedia Britannica is a dinosaur. The encyclopedia’s last print version is the 32-volume 2010 edition, which weighs about 130 lb and costs $1,395. Only 8,000 sets were sold, compared with 120,000 sets sold per year during the printed encyclopedia’s golden days, which peaked in 1990.

Anyone can still get the information they need from the encyclopedia’s online version, which costs $70 per year and collects no dust; you just can’t sit on the floor with one of the volumes in your lap and feel the knowledge.

When cola drinks were invented as tonics in the late 1800s, who knew we would have methylimidazanity in 2012? Much like the Linsanity associated with the sudden fame of basketball player Jeremy Lin of the New York Knicks this year, 4-methylimidazole (4-MEI) has taken the cola world by storm.

Credit: Shutterstock
Famous molecule: 4-MEI makes it to prime time.
A glass of cola, which contains 4-MEI, a suspected cancer causing chemical.
Credit: Shutterstock
Famous molecule: 4-MEI makes it to prime time.

The Newscripts blog reported last year (March 9, 2011) that caramel coloring used to improve the eye appeal of colas had been taking fire for containing 4-MEI and its 2-methyl isomer (2-MEI). These chemicals are by-products when sugar is pyrolyzed with the aid of ammonium compounds in the caramelization process.

A 2007 National Toxicology Program report concluded that a high dose of 4-MEI caused cancer in mice. A 2004 NTP report made a similar conclusion about 2-MEI. But the Food & Drug Administration doesn’t seem to think there is enough risk to regulate the methylimidazoles: Caramel coloring is a “generally recognized as safe” food ingredient, according to the agency.

Enter the State of California, which cited NTP’s report last year when it added 4-MEI to its list of some 500 chemicals known to cause cancer or reproductive toxicity. California didn’t include 2-MEI on its list because the compound apparently doesn’t show up in caramel coloring. California set a “safe harbor” exposure level for 4-MEI of 16 µg per day. Any product containing more than that amount, presumably per serving, must carry a cancer warning on its label.

A University of California, Davis, study on cola drinks found that they contain about 10 µg of 4-MEI per oz, so a 12-oz can of cola significantly exceeds the safe-harbor level. But the American Beverage Association pointed out in a recent press release that a person would need to drink 2,900 cans of cola per day to equal the amount of 4-MEI given to lab animals in the NTP study.

Rather than stamping their cans and bottles with a skull and crossbones, Coca-Cola and PepsiCo announced a few weeks ago that they were opting to tone down their recipes by backing off the 4-MEI. Although it was widely reported elsewhere in the media that Coke and Pepsi have changed their world-famous recipes, that isn’t true, the companies say. They simply asked caramel-coloring suppliers to ensure that the additive contains less 4-MEI.


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