Personal Care

Replace SLES and SLS with surfactants that contain no alkyl sulphate: alpha olefin sulphonate, sodium cocoyl or lauroyl isethionate, sodium lauryl sarcosinate, or glucosides such as coco and lauryl glucoside, usually with cocamidopropyl betaine for foam and mildness. Alpha olefin sulphonate thickens fairly easily, but many other sulphate-free systems respond poorly to salt, so formulators add a thickener such as PEG 150 distearate or xanthan gum and confirm pH, clarity and foam in trials.

Cocamidopropyl betaine is an amphoteric co-surfactant that makes SLES-based shampoos and body washes gentler, gives a denser and more stable foam, and helps the formula thicken when salt is added. It works as a secondary surfactant alongside the main anionic rather than on its own. Check the betaine's active content and its sodium chloride level on the COA, because both change how much salt the formula needs to reach its target viscosity.

HLB (hydrophilic-lipophilic balance) runs from about 0 to 20 and shows whether an emulsifier prefers oil or water. Low-HLB emulsifiers, roughly 3-6, form water-in-oil emulsions; those of about 8-18 form oil-in-water creams and lotions; those above about 15 solubilise fragrance into water. Formulators often pair a low-HLB emulsifier such as glyceryl monostearate (about 3.8) with a high-HLB one such as PEG 100 stearate or a polysorbate to match the oil phase.

It depends mainly on the abrasive. Sodium fluoride releases free fluoride ions that react with calcium abrasives such as calcium carbonate or dicalcium phosphate to form insoluble calcium fluoride, so it is normally paired with silica. Sodium monofluorophosphate keeps its fluoride bound to phosphate and is the usual choice with calcium-based abrasives. Stannous fluoride needs a specially stabilised formula. In every case total fluoride must stay within the limit of the applicable standard.