Sodium hydroxymethylglycinate is a synthetic preservative that works by slowly releasing small amounts of formaldehyde. It's typically used in formulations as a paraben-free preservative, though it's controversial for the same reason it works.
How is it used?
If used, add to the water phase — but given the regulatory direction and sensitization risk, this is generally not recommended as a first-choice preservative.
Forms
Available forms and grades affect how this ingredient behaves and how it should be selected for a formula.
Appearance
Color, texture, and physical characteristics can vary between suppliers and product grades.
Usage rate
Recommended incorporation levels depend on product type, supplier guidance, and the intended result.
Why we use it
Formulators choose this ingredient for specific performance, sensory, and stability benefits.
Strengths and limitations
Its advantages, compatibility considerations, and practical tradeoffs should be weighed during development.
Alternatives and substitutions
Possible replacements depend on the ingredient's role, desired skin feel, and formulation system.
Storage and shelf life
Appropriate storage conditions help protect quality and performance throughout the ingredient's usable life.
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