Sodium nonanoyloxybenzenesulfonate (NOBS) is an important component of laundry detergents and bleaches.

[1] 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[2] and was first used in American laundry detergents in 1988.

[4] Compared to TAED, which is the predominant bleach activator used in Europe, NOBS is efficient at much lower temperatures.

[5] When attacked by the perhydroxyl anion (from hydrogen peroxide), NOBS forms peroxynonanoic acid (a peroxy acid) and releases the leaving group sodium 4-hydroxybenzene sulfonate, which is an inert by-product.