While Clorox Regular bleach (in the U.S.) is 6%, most off-brand regular bleaches are 3% or less, but the off-brand Ultra bleaches are 6%. As for what is in bleach, if 6% sodium hypochorite, then it also has 4.7% sodium chloride (salt) with the rest, 88.7%, water. There is a very small amount of excess lye, the amount varying by brand, but in Clorox Regular it's around 0.06%.