Washing Powder

Almost all washing powder contain a surfactant–the ingredient that provides most of the cleaning power. Today, use anionic surfactants such as alkyl sulfates and non-ionic surfactants instead. These molecules have water-loving (hydrophilic) heads and long water-avoiding (hydrophobic) hydrocarbon tails. When you wash clothes, the hydrophobic tails of surfactant molecules are attracted to any oil and grease on the clothes' surface. A group of surfactant molecules then surround the oil droplets, forming spheres with the oil trapped inside. These spheres – called micelles – lift off the clothes' surface and get washed away down the drain.

Some washing powder also contain bleaching agents that release hydrogen peroxide during the wash cycle. The hydrogen peroxide oxidises stains from certain foods and from gardening, such as chlorophyll (found in grass).

The oxidation breaks down the stains, making it easier to wash them away. These bleaching agents are why people used hot washes in the past: hydrogen peroxide is only an effective bleach at temperatures over 60℃. Today, we can use colder washes as washing powder also contain bleach activators – molecules that react with hydrogen peroxide to produce peroxy acids, which then act as the bleach on clothes.

Biological washing powder also include enzymes. These break down stubborn stains, such as fats and proteins, into smaller molecules in the same way they work in our bodies. While enzymes are great at cleaning clothes, they can irritate some people's skin. Non-bio detergents don't contain enzymes and usually avoid colourings and fragrances to make them even kinder to sensitive skin.

Washing powder can also contain water softeners, known as chelating agents. These react with metal ions from dissolved minerals (such as calcium and magnesium) found in hard water. In doing so, the chelating agents prevent the minerals from reacting with the surfactant because this makes it less effective at washing and also forms a horrible foamy scum in the machine. Alkali builders are another handy addition to washing powder. Some fabrics (such as cotton) have a negative surface charge. By increasing the alkalinity of your wash, you increase the charge, causing mutual repulsion and helping to boost cleaning power.

Acrylic Acid Homopolymer – Also known as polyacrylic acid or Carbomer, this alkali salt is used as a dispersing agent in detergents, paint, and nail polishes. It keeps liquid combinations together (think of an emulsified oil and water mixture, such as mayonnaise or salad dressing) and allows for ingredients to be evenly concentrated throughout the liquid.

Alkyl Ethoxy Sulfate – A common anionic surfactant (see below) used in shampoo, liquid soap, dishwashing detergent and laundry detergent. AES helps remove dirt and oil from fabrics (or dishes or your hair and skin) and create suds.

Alkylbenzene Sulfonic Acid – Also sometimes listed as linear alkylbenzenesulfonate, this is one of the most widely used anionic surfactants in the world. It's been around since 1964, and can be found in many liquid soaps, shampoos, dishwashing detergents and laundry detergents. In detergents, it surrounds dirt and oils and then bonds with water to remove them with the rinse cycle.

Anionic Surfactant – These molecules have a negatively charged end that is attracted to water (hydrophilic) and repelled by the fabric. The other end of the same surfactant molecule is attracted to dirt and oil and bonds with those particles. Anionic surfactants create suds and help penetrate the fabric to remove dirt and oil.

Amylase – An enzyme that targets and breaks down starch-based stains such as from corn, potatoes, rice, and many thickeners.

Borax Pentahydrate – In liquid laundry detergents, this ingredient helps to stabilize enzymes and keep them from degrading in the bottle. It also softens water to allow the surfactants to work better. In powdered detergents, it is used to adjust pH.

Calcium Chloride – This ingredient is used in laundry detergents to stabilize enzymes and keep them from degrading in the bottle.

Carboxymethylcellulose – A polymer that contains plant fibers and is sometimes used in liquid laundry detergents to help build the viscosity – or to make the liquid thicker and less runny. It also helps keep dirt that has been removed from clothes from settling back onto them.

Citric Acid – This ingredient is common in sour foods and citrus juices, but when used in laundry detergents it helps to prevent mineral buildup on your clothes and your washing machine.

Disodium Distyrylbiphenyl Disulfonate – An optical brightener that coats clothing fibers to make them appear more white or bright. It's similar to the former whitening technique known as “bluing” and works by causing the fabric to reflect more blue light vs. yellow light. Your clothes come from the store coated with optical brighteners. As these wear off over time or with repeated washing, clothes appear dingy and less white. This ingredient adds the brighteners back to the clothing fibers.

Ethoxylated C12-15 Alcohols – These non-ionic surfactants are a “fatty alcohol” that helps break the surface tension of water. This allows your laundry to get wet and the cleansers to penetrate the clothing fibers. Linear surfactants biodegrade quickly and are more environmentally friendly. They are widely used in laundry detergents, cosmetics, and glass or surface cleaners.

Fragrance – An optional ingredient in laundry detergent to make your clothes smell clean, fresh, and pleasant.

Hydrated Silica – This compound naturally occurs in the form of the opal gem and as diatomaceous earth. About 12 percent of the earth's crust is made of silicon dioxide, from which hydrated silica is derived. It's commonly used in toothpastes and as a stabilizer in beer. In laundry detergents, you'll usually find it in the individual paks to aid in breaking down the packet and helping other ingredients work.

Hydrogen Peroxide – Some laundry detergents and stain pretreatment solutions contain hydrogen peroxide to help whiten and brighten clothes, disinfect them, and reduce soap buildup. It breaks down into oxygen and water, so it's safe for the environment and your home.