| MadSci Network: Chemistry |
After asking a few colleagues and trying to find information on the web, I do not have a clear answer for your question. I would recommend that you contact the company (perhaps they have a consumer number on the label) to see how much they will tell you about it. They might not tell you much, depending on how proprietary the information is.
The bluing agents used in laundry detergents (and, I discovered, pet shampoo to whiten coats!) are dyes that are applied to make everything a little bluer. Blue is the complementary color to yellow. This makes a "yellowing" white fabric appear white again, because now your eye sees the combination of yellow and blue.
Most dyes are organic molecules, so bluing agents probably are, too. As you might already know, many different chemicals can be used to promote crystal growth. The bluing agent may act as a catalyst for the crystallization of salt.
Good luck, and do not hesitate to resubmit this question if you're still in a stump.
Try the links in the MadSci Library for more information on Chemistry.