Tuesday, January 05, 2010

Is it white or is it fluorescent?

Think about ultra-bright copy paper, and brand new white clothes. How did they get so white? Lots of bleach? Think again. Bleach only gets the color so far. And a lot of companies use what are called "fluorescent whitening agents" to get that "whiter than white" look. These are chemicals that glow slightly blue under a ultraviolet light to compensate for the dingy look of partially bleached materials. The subtle blue plus dingy yellow gives you a nice bright white. They also glow under a black light.

But don't worry. These chemicals are non-toxic (though I wouldn't eat them). Just another example of how chemistry makes life better. And brighter. Want to know more? Here's a good link.

ps - You might think these would also be used in teeth whiteners. Especially after that Friends episode. But teeth whiteners are actually bleaches like hydrogen peroxide. These bleaches don't just clean the enamel (which starts to wear away over time), but bleach the off-white dentin behind the enamel.

1 comment:

Kenna said...

Hmmmmm. . .