Hand cleaners remove tough, sticky soils from hands through a combination of physical, chemical, and sometimes enzymatic actions. These cleaners often contain surfactants, which are compounds that lower the surface tension between the skin and the soil, allowing the soil to be lifted and suspended in water. Surfactants have hydrophilic (water-attracting) and hydrophobic (water-repelling) ends, which help to emulsify oils and grease, breaking them down into smaller particles that can be rinsed away.
Abrasives are another key component in many hand cleaners, especially those designed for heavy-duty cleaning. These small, gritty particles physically scrub the skin, helping to dislodge stubborn dirt and grime. Common abrasives include pumice, silica, or polymer beads.
Some hand cleaners also contain solvents, which dissolve sticky substances like adhesives, tar, or paint. These solvents can be natural, such as citrus-based oils, or synthetic, like mineral spirits or alcohols. They work by breaking down the chemical bonds in the sticky substances, making them easier to remove.
Additionally, certain hand cleaners incorporate enzymes, which are biological molecules that catalyze the breakdown of organic materials. Enzymes can be particularly effective against protein-based soils or food residues.
Moisturizers and skin conditioners are often included in hand cleaners to counteract the drying effects of surfactants, abrasives, and solvents, helping to maintain skin health and prevent irritation.
Overall, the effectiveness of a hand cleaner in removing tough, sticky soils depends on the combination and concentration of these ingredients, as well as the method of application, such as rubbing or scrubbing, which enhances the mechanical removal of soils.