Cleaning agents are substances (usually liquids, powders, sprays, or granules) used to remove dirt, including dust, stains, bad smells, and clutter on surfaces. Purposes of cleaning agents include health, beauty, removing offensive odor, and avoiding the spread of dirt and contaminants to oneself and others. Some cleaning agents can kill bacteria and clean at the same time.
Cleaning agents normally water solutions that might be acidic, alkaline, or neutral, depending on the use. Cleaning agents may also be solvent-based or solvent-containing and are then called degreasers.
Acidic cleaning agents are mainly used for removal of inorganic deposits like scaling. The active ingredients are normally strong mineral acids and chelants. Often, surfactants and corrosion inhibitors are added to the acid.
Hydrochloric acid (also called muriatic acid) is a common mineral acid typically used for concrete. Vinegar can also be used to clean hard surfaces and remove calcium deposits. Sulfuric acid is used in acidic drain cleaners to unblock clogged pipes by dissolving greases, proteins, and even carbohydrate-containing substances such as toilet tissue.
Alkaline cleaning agents contain strong bases like sodium hydroxide or potassium hydroxide. Bleach (pH 12) and ammonia (pH 11) are common alkaline cleaning agents. Often, dispersants, to prevent redeposition of dissolved dirt, and chelants, to attack rust, are added to the alkaline agent.
Neutral washing agents are pH-neutral and based on non-ionic surfactants that disperse different types of dirt.
Cleaning agents specially made for removal of grease are called degreasers. These may be solvent-based or solvent-containing and may also have surfactants as active ingredients. The solvents have a dissolving action on grease and similar dirt. The solvent-containing degreaser may have an alkaline washing agent added to a solvent to promote further degreasing. Degreasing agents may also be made solvent-free based on alkaline chemicals and/or surfactants.
Common cleaning agents
- Water, the most common cleaning agent, which is a very powerful polar solvent
- Soap or detergent
- Calcium hypochlorite (powdered bleach)
- Citric acid
- Sodium hypochlorite (liquid bleach)
- Sodium hydroxide (lye)
- Acetic acid (vinegar)
- Various forms of alcohol - like isopropyl alcohol or rubbing alcohol
- Sodium bicarbonate (baking soda)
- Tetrachloroethylene (dry cleaning)
- Carbon dioxide
- Chromic acid
- Trisodium phosphate
- Saltwater soap (a potassium based soap)
- Sodium percarbonate
- Sodium perborate
- Acetone (can damage plastics)
- Amyl nitrite and other nitrites
- Xylene (can damage plastics)
- Freon-Dichlorodifluoromethane (discontinued in 1995 due to damage to the ozone layer).