Glossary
A class of cosmetic preservatives that slowly release small amounts of formaldehyde gas to prevent microbial growth in water-containing products. Common formaldehyde releasers include DMDM hydantoin, imidazolidinyl urea, diazolidinyl urea, quaternium-15, and bronopol.
Formaldehyde is one of the most effective broad-spectrum antimicrobials known. At very low concentrations, it kills bacteria, yeasts, and molds that would otherwise grow in water-based cosmetics. Rather than adding formaldehyde directly (which would raise immediate safety concerns), manufacturers use ingredients that slowly release it over time, maintaining a continuous low-level antimicrobial effect.
The FDA allows formaldehyde releasers in cosmetics at concentrations designed to keep free formaldehyde below 0.2 percent. At these levels, the formaldehyde concentration is considered safe by regulatory standards. However, consumer concern about formaldehyde exposure has made these ingredients increasingly controversial.
The simplest way to avoid formaldehyde releasers is to choose products that do not require preservatives at all. Water-free skincare formulations, made entirely from oils, butters, and waxes, cannot support microbial growth and need no preservatives of any kind. This is the approach Goodfriend Honey Co. takes with every product.
For water-based products, phenoxyethanol, potassium sorbate, and sodium benzoate are commonly used alternatives. While these are not entirely controversy-free either, they do not involve formaldehyde release.
Look for these ingredient names: DMDM hydantoin, imidazolidinyl urea, diazolidinyl urea, quaternium-15, bronopol (2-bromo-2-nitropropane-1,3-diol), and sodium hydroxymethylglycinate. If any of these appear on the label, the product contains a formaldehyde-releasing preservative.
The question is debated. At the low concentrations released by cosmetic preservatives, regulatory agencies consider the exposure safe. However, formaldehyde is classified as a known human carcinogen by the International Agency for Research on Cancer (IARC), and sensitive individuals may experience contact dermatitis from formaldehyde releasers.
Without water, bacteria, mold, and yeast cannot grow. Microorganisms require water (measured as water activity) to survive and reproduce. In a product with zero water content, the environment is too inhospitable for microbial growth, eliminating the need for any preservative.
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