Heres the arm and hammer web site. It is baking soda (duh)
You wont believe all the uses for this stuff.[up]
What can ARM & HAMMER® Baking Soda do for my laundry?
We're glad you asked! Our larger 4 lb. box or our 12 lb. Resealable Pouch with it's enclosed scoop make using
ARM & HAMMER® Baking Soda in the laundry easy. Here's how:
Cleaning Booster-- ARM & HAMMER® Baking Soda works with your liquid laundry detergent to make it work harder for you (it's a pH thing!). Just add 1/2 cup of ARM & HAMMER® Baking Soda to your wash with the usual amount of liquid detergent.
ARM & HAMMER® Baking Soda can also help your chlorine bleach work harder for you… add 1/2 cup of ARM & HAMMER® Baking Soda with a 1/2 cup of bleach (instead of the usual 1 cup) to get whites whiter without smelly harsh chemicals that can damage clothes.
Deodorizing Clothes—Freshen any smelly laundry—work shirts, baby bibs, musty towels—by adding 1/2 cup of ARM & HAMMER® Baking Soda in the rinse cycle to neutralize and eliminate odors. As a cloth diaper soak, dissolve 1/2 cup of ARM & HAMMER® Baking Soda in 2 quarts of water to keep those smells down.