The Complete Handbook of Bleach

Chapter 1: Understanding Bleach

What Bleach Actually Is

At its core, bleach is a chemical compound that degrades organic molecules through oxidation. The word "bleach" describes a function, not a single substance: anything that removes color or whitens by chemically altering chromophores (the parts of a molecule that absorb visible light) is technically a bleach. But in commercial practice, the term refers to a much smaller set of compounds, nearly all of which fall into two families: chlorine-based bleaches and oxygen-based bleaches.

The most common chlorine bleach is sodium hypochlorite (NaOCl), typically sold as an aqueous solution containing 5-12% available chlorine by weight. Household liquid bleach is usually a 5-6% solution. Industrial and institutional formulations range from 8% to 12.5%, often labeled as "commercial strength" or "industrial bleach." When you pour this solution into water, it rapidly establishes an equilibrium that produces hypochlorous acid (HOCl), which is the species primarily responsible for the oxidizing action. The term "available chlorine" refers to the amount of chlorine gas needed to produce the same oxidizing power as the hypochlorite solution, expressed as a percentage by weight. This is the number you should care about when comparing products, not the raw concentration of NaOCl.

Oxygen bleaches work on the same principle but instead use hydrogen peroxide (H2O2) or compounds that release it, like sodium percarbonate (2Na2CO3 * 3H2O2) and sodium perborate. Sodium percarbonate is a solid crystalline powder that dissolves in water to release hydrogen peroxide and soda ash. This makes it the active