Laundry Detergent Ingredients and How They Work

Laundry detergent ingredients have evolved from bar soaps made of animal fat and lye to scrubbing chemicals and enzymatic stain fighters. Today, both natural and synthetic detergent options will keep your laundry looking and smelling fresh. Learn more about basic laundry detergent ingredients and the chemistry that goes into making them work.

Basic Detergent Formulas

Every detergent manufacturer has secret ingredients and mixtures to produce their specific brands. Many of these ingredients can be manufactured from plants; others are petroleum-based. The amount of each ingredient and how they are combined affects a detergent's cleaning ability. 

Alkalies

Alkalies, a major component in most laundry detergents, are soluble salts and a base that reacts with an acid to neutralize it. They are effective in removing dirt and stains from fabric without excessive rubbing. Soluble salts of an alkali metal, such as potassium or sodium, are good grease removers. They form an emulsion of the oily or solid particles held in suspension in wash water to be rinsed away. When added to the laundry detergent, the alkalies react with the fats in the formula to make soap.

The first soap and detergent makers used plant ashes to produce alkalis. Today they are chemically produced by running electricity through salt water to produce sodium hydroxide (NaOH), caustic soda and potassium hydroxide (KOH), or caustic potash. These are the most commonly used alkalies in soaps and detergents.

Alkaline substances vary in their strength with the strongest causing burns and internal injuries if swallowed. But, because all detergents are correctly formulated to ensure alkalies neutralize with other ingredients, this shouldn't be a cause of concern.

Some varieties are:

• A mild alkali is baking soda (sodium bicarbonate).
• Moderate alkalies include household ammonia, borax, and trisodium phosphate (TSP).
• Strong alkalies include washing soda (sodium carbonate) and lye (caustic soda).

Surfactants and Anti-Redepositing Agents

Surfactants are one of the major components of laundry and cleaning products. In washing machines, surfactants lift dirt and oils off the fabric and attach them to the water, so the dirt gets rinsed away when the water drains out of the machine. They break up stains and suspend the dirt in the water to prevent the redeposition of the dirt onto the surface.

They work like an oil and vinegar salad dressing. They do not mix unless shaken vigorously in the bottle and separate almost immediately afterward. The same is true when washing clothes. Surfactants stick to the soil in clothing, making it dispersible and able to be removed with the wash water. As the water swishes around, the oil is lifted into the water and swished away.

Types of surfactants include:

• Alkyl sulfates (anionic)
• Alkyl ethoxylate sulfates (anionic)
• Ethers of fatty alcohol (non-ionic)

Anionic vs. Non-Ionic Surfactants

In anionic surfactants, the head of the molecule is negatively charged. This type of surfactant is very good at removing oily dirt and stains unless used in water full of minerals, including calcium and magnesium. The minerals keep the anionic surfactant from working properly. Anionic surfactants are listed as alkyl sulfates, alkyl ethoxylate sulfates, and soaps in the ingredient list.

If you have hard water, you will get better cleaning results with a non-ionic surfactant. These surfactant molecules have no electrical charge. These surfactants are listed as ethers of fatty alcohols on the label. You might find them combined with anionic surfactants to complement and boost cleaning action.

Functional Materials in Laundry Detergent

A functional material has a unique characteristic that helps it perform in a specific way when it is exposed to other materials and stimuli, such as the odors in workout clothes. Here are functional materials in laundry detergents:

• PH modifiers to balance acids and bases in water
• Optical brighteners (bleach alternative) improve the appearance of whiteness by absorbing UV light and giving off a blue tint
• Water conditioners to manage hard water and inhibit dye transfer
• Suds control with soap or silicone to prevent excess foaming
• Preservatives to prevent microbial growth

Catalytic Enzymes 

Enzymes, such as the following, can be natural or processed chemically. Different enzymes target specific soils, and the catalytic action breaks the soil into smaller molecules to be washed away.

• Protease: Degrades protein-based soils
• Amylase: Degrades starch-based or carbohydrate soils
• Cellulase: Breaks down cotton fibers to release soils
• Lipase: Degrades fat-based soils
• Mannanase: Degrades food-based stains
• Pectinase: Degrades fruit-based stains

Enzymes are naturally occurring; they help bread rise faster and increase wine yields. The introduction of enzymes into laundry detergents dramatically changed how we do laundry. Enzymes allow us to use lower water temperatures and less detergent to clean clothes. For many years, the only way to achieve clean laundry was to use boiling water and harsh lye-based soaps.

Today, scientists have created industrial biotechnology or "white biotech," which uses enzyme cells or components of cells to generate industrially useful enzymes for laundry detergents. Industrial biotechnology has the potential to save the planet billions of tons of CO2 emissions per year and support building a sustainable future.

Fragrance

Fragrances influence the perception of cleanliness. They are often added to the detergent composition and mixed during production. While clean, light, floral scents can be refreshing, scented laundry detergent can also contain hazardous chemicals that can cause skin irritation or other health issues. Laundry detergent fragrances can also harm the environment.

It is best to choose safer options labeled "fragrance-free." However, if you wish to scent your laundry, do so naturally with a drop of essential oil to your unscented laundry detergent before you begin the wash load. Lavender, vanilla, tropical scents, clean linen, and rainwater are popular scents to keep your clothes smelling fresh post-wash.

Colorant or Dyes 

Dyes are added for the aesthetic appeal to the customer. They perform no role in cleaning.

How Detergents Work to Clean Clothes

There is a three-fold process, including chemical energy, thermal energy, and mechanical energy that must be used when washing clothes to get the best results from any laundry detergent.

• Chemical energy: The chemical energy is the laundry detergent. The ingredients in the laundry detergent you choose will affect the final results. Less expensive detergents have fewer or no enzymes. Fewer enzymes equal less cleaning power.
• Thermal energy: This pertains to water temperature. Different detergents are formulated to work best at different temperatures. Read the directions to select the best product for your laundry. While all soaps benefit from warmer water, we know that heat sometimes ruins certain fabric types. As a result, some laundry detergent formulas have been designed to compensate for the lack of heat, with more surfactants and alkalies to stick to the soils and convert the cold fats, so it still cleans without the heat.
• Mechanical energy: This comes from either a washer or a person hand-washing clothes.

How to Select the Best Detergent

There are dozens of choices on the laundry detergent shelves. How do you choose? The best one suits your family’s needs to work well on specific stains, a preference for fragrance, a favorite form (powder, liquid, or single dose), and price.

• Observe common stains: Start by assessing your household's common stains and soils. If most of the garments are only lightly soiled with few stains, you might find that a less expensive detergent and a good stain remover are all you need. Use a heavy-duty detergent for heavily soiled items, gym clothes with lots of body odor, and garments with food/grease/outside stains.
• Read labels: Know what's in the detergent or go online to read the ingredients. Look for surfactants and enzymes to remove soil and stains. Bargain brands have fewer of these components and will not clean as well. You might find that having two formulas on your laundry shelf will serve your needs: a detergent for lightly soiled clothes and one for heavily soiled clothes.
• Pick cold or hot: Although most detergents will work in cold water, choose one formulated for cold water if you plan to use cold water exclusively.
• Choose a formula: Liquids and powders come in concentrated or ultra formulas. Although packaged in smaller sizes, they provide the same cleaning power as their larger unconcentrated counterparts. To determine the correct amount, follow the label instructions and use the companion measuring cup or scoop. These products have the extra water or fillers removed making them easier and less expensive to ship and store. The single-dose packs and pods are concentrated even further and might save you money by preventing overuse.
• Find a favorite scent: Many people choose their laundry detergent based on scent. Remember that "smelling clean" is not the same as being clean. Be sure that soil is removed and not just covered up with perfume.