 NOBS is formed by the reaction of nonanoic acid (or its esters) with phenol followed by aromatic sulfonation using SO3 to form a sulfonic acid at the para-position.NOBS was developed by Procter & Gamble in 1983 and was first used in American laundry detergents in 1988.NOBS is the main bleach activator used in the U.S.A. and Japan.