Ethylisothiazolinone ●
TL;DR. This ingredient is used as a synthetic preservative and antimicrobial agent, mainly to control bacteria, yeast, and mold in water-based formulas.
What does Ethylisothiazolinone do in a cosmetic formula?
This ingredient is used as a synthetic preservative and antimicrobial agent, mainly to control bacteria, yeast, and mold in water-based formulas.
Is Ethylisothiazolinone clean?
It has significant clean-standard friction because this preservative family is associated with contact allergy and tight regulatory scrutiny. Many clean-beauty frameworks flag or exclude it, especially in leave-on products.
Is Ethylisothiazolinone sustainable?
This material is synthetically made, typically from petrochemical feedstocks, and is used at very low levels. Its biocidal purpose creates aquatic-life concerns during manufacturing and wastewater release, even when formula concentrations are small.
Is Ethylisothiazolinone COSMOS-approved?
It is not permitted under COSMOS-natural or COSMOS-organic standards. From a Green Chemistry view, it scores poorly because it is a synthetic biocide with sensitization concerns and limited alignment with renewable sourcing or benign end-of-life principles.
How does Ethylisothiazolinone work chemically?
The molecule is a small sulfur- and nitrogen-containing heterocycle with a carbonyl group, built to interfere with microbial enzyme systems. Formulation use is tightly constrained by sensitization potential, and performance can be affected by pH, reducing agents, and nucleophilic ingredients that may deactivate the reactive ring.
Last updated 2026-05-16