Database/Preservative/Methylisothiazolinone
100% petroleum · ISO 16128

Is Methylisothiazolinone natural?

No. The isothiazolinone ring and methyl group are synthesised entirely from petrochemical starting materials.

INCI nameMethylisothiazolinone
CAS2682-20-4
FormulaC4H5NOS · 115.16 Da
FunctionPreservative
FeedstockManufactured via multi-step organic synthesis from petrochemical amide…

How we scored it

Isothiazolinone ring built via petrochemical amide/sulfur chemistry → 0/total = 0.0.
What counts. ISO 16128-2 scores the atoms that remain in the final ingredient. Reagents, solvents, catalysts and protecting groups used during manufacture leave no mass behind and are not counted.

Where it comes from

Manufactured via multi-step organic synthesis from petrochemical amide and sulfur-chemistry intermediates. No natural or fermentation route is used commercially.

In plain English

A fast-acting preservative used at very low levels to stop bacterial and fungal growth in water-based cosmetics. It is a fully man-made molecule manufactured from petrochemical starting materials.

CosIng definition: Methylisothiazolinone is the heterocyclic organic compound that conforms to the formula:

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Structure

2D structure of Methylisothiazolinone

2-methyl-1,2-thiazol-3-one

PubChem CID 39800 ↗

References

  1. 1ISO 16128-1:2016 and ISO 16128-2:2017 — Guidelines on technical definitions and criteria for natural and organic cosmetic ingredients and products. ISO, Geneva.
  2. 2Methylisothiazolinone. PubChem CID 39800. National Center for Biotechnology Information. pubchem.ncbi.nlm.nih.gov ↗
  3. 3METHYLISOTHIAZOLINONE. CosIng — European Commission cosmetic ingredient database. ec.europa.eu/cosing ↗
  4. 4METHYLISOTHIAZOLINONE. CosIng u2014 European Commission database for information on cosmetic substances and ingredients. https://ec.europa.eu/growth/tools-databases/cosing/search?search=METHYLISOTHIAZOLINONE