Preservatives & Stabilizers

A broad-spectrum preservative protects a formula against all three main types of microbe: bacteria, mold, and yeast. Many single ingredients cover only some of these, which is why formulators use broad-spectrum options or ready-made blends. Any water-containing cosmetic needs broad-spectrum protection to stay safe over its shelf life.

If it contains water, yes. Water-based creams, lotions, gels, toners, and anything you dip wet fingers into will grow bacteria, mold, and yeast within days without a broad-spectrum preservative. Anhydrous products made only of oils, butters, and waxes do not need a water-phase preservative, though an antioxidant helps them last.

Both are widely used, and the right one depends on your formula. Phenoxyethanol is a globally approved, paraben-free preservative often paired with a booster for full coverage. Germall Plus is a formaldehyde-releasing preservative effective across many formulas. Check each product's approved pH range and attributes, and pick the one that fits your product and label preferences.

Disodium EDTA is a chelator. It binds the metal ions found in hard water and plant extracts, which would otherwise feed microbes and destabilize a product. This boosts your preservative's performance and improves stability. It is used at a low level, around 0.1 to 0.2 percent, in the water phase, and it works alongside a preservative rather than replacing it.

Most cosmetic preservatives work at well under 1 percent, and each has its own recommended level and pH range on the listing. Phenoxyethanol, for example, is commonly used at 0.5 to 1 percent. More is not better, since overdosing wastes product and can irritate skin. Add at the stated level and test your finished formula.

Several are, including phenoxyethanol and phenoxyethanol-based blends and Optiphen options. If a paraben-free label is important to you, check each product's attributes, since the range includes both paraben-free options and other broad-spectrum systems. The listing states what each one contains.

It depends on the preservative. Some are heat-stable and can be added to the water phase, while many are added during the cool-down phase, once the mixture has dropped below a stated temperature, to avoid degrading them. Follow the temperature guidance on the listing, and add the chelator to the heated water phase