researchers at Virginia Polytechnic Institute found that when products containing triclosan are mixed with water, a chemical reaction between chlorine and triclosan occurs, creating chloroform. That's not really the best gas to be inhaling while you're brushing your teeth. Just sayin.
Triclosan is in Colgate 2 in 1 toothpaste, Colgate Toothpaste Clean Mint, Colgate Total Plus Whitening Toothpaste, Colgate Total Gel Mint Stripe Toothpaste, Colgate Total Advanced Fresh Anticavity Fluoride & Antigingivitis toothpaste and thirty other toothpastes, a list of which you can find on the Cosmetics Database. If you want a recommendation of what to replace your old tube with, see my post on Jasons toothpastes. Triclosan is also in mouthwashes, so check the Cosmetics Database for a full list.
In other words, check the label of your toothpaste! And maybe chuck it in the waste basket, slam dunk.