Dear Straight Dope:
I enjoyed your recent "Mountain Dew" article, especially its reference to "yellow #5," as it identified the actual chemical, tartrazine.
I may be dating myself by recalling the "red dye #2" panic and the furor about those deadly red M&M's. I also remember that very few articles at the time actually named the chemical itself.
My question is much more innocuous. Why are food-grade dyes numbered, instead of being identified by a chemical name? Who started this system, and why? And how can I find out what "blue #2" is, so I can fret about my M&M's yet again?
SDStaff Melis replies:
The numbering system has several purposes. First, it lets you know that the Food and Drug Administration has approved the coloring for consumer use. If the number is in the form “FD&C x,” that means the chemical can be used in food, drugs, and cosmetics. If you see just a D&C, that means it was approved for only drugs and cosmetics, not food. Second, the numbers alert you that this is, in fact, an artificial coloring agent. Third, the numbers make for much easier label-reading than the actual chemical names. If there’s any question of safety — if, for example, the product is found to have long-term side effects — it’s also easier to yank off the shelf or avoid.
Some consumer advocates suggest we try to avoid products that are artificially colored and/or flavored. Are there natural coloring agents and flavorings? Sure, but the artificial stuff does have a longer shelf life and is more consistent from batch to batch.
To find out the chemical names of the different products, as well as to keep tabs on the latest studies, keep an eye on Web sites like the FDA’s home page at http://www.fda.gov
SDStaff Melis, Straight Dope Science Advisory Board
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