4-Methoxyphenol (MEHQ), CAS 150-76-5, is a phenolic polymerization inhibitor used in polymerization control in selected acrylic and vinyl monomer systems. For procurement review, confirm assay, required inhibitor performance, physical form, and handling requirements, the actual packaging, and applicable safety documentation.
4-Methoxyphenol (MEHQ) CAS 150-76-5
- CAS: 150-76-5
- Synonyms: 4-Methoxyphenol; p-Hydroxyanisole; MEHQ; Hydroquinone monomethyl ether; Mequinol
- Einecs: 205-769-8
- Molecular Formula: C₇H₈O₂
- Grade: Confirm assay and inhibitor-performance requirements
- Package: Confirm packaging for the offered solid form
Product Description
Product: 4-Methoxyphenol (MEHQ); CAS number: 150-76-5.
Identity boundary: 4-Methoxyphenol (MEHQ) is not BHA (butylated hydroxyanisole). These are different substances and RFQs should use CAS 150-76-5 for MEHQ.

Technical context: polymerization control in selected acrylic and vinyl monomer systems. Procurement review: Confirm assay, required inhibitor performance, physical form, and handling requirements, the actual packaging, and applicable safety documentation for the actual offered material.
FAQ - Technical & Supply Chain
-
Q:
Are 4-Methoxyphenol, Hydroquinone Monomethyl Ether and MEHQ the same substance?
A: Yes. These names commonly identify CAS 150-76-5, also called p-hydroxyanisole. Do not confuse MEHQ with hydroquinone, catechol or anisole; they have different identities and inhibitor behavior. Contracts, labels and COA documents should use the full name and CAS number because the abbreviation alone does not define the supplied substance. -
Q:
Which batch controls should be set for industrial MEHQ?
A: Agree assay and method, melting range, water, color, hydroquinone and other specified organic impurities, ash or nonvolatile residue, and particle form where dissolution rate matters. Check the batch COA against the same test methods used for approval. A nominal purity statement alone does not establish suitability for a monomer inhibition system. -
Q:
How should MEHQ requirements be defined for monomer stabilization?
A: State the monomer, target inhibitor concentration, dosing basis and permitted contribution from the incoming monomer. Confirm whether MEHQ will be added as solid or as a prepared solution and define any solvent restrictions. Inhibitor performance also depends on oxygen, temperature and residence time, so the end user should validate the complete storage system.
Ordering & Documentation
Key information for document requests, quotations, and supply planning.
Documents
COA, TDS, SDS/MSDS and packing details are available on request.
Quotation
Send the CAS number, grade, quantity, packing preference and destination.
Sample & Supply
Support is available for samples, trial orders, bulk and repeat supply.
Storage & Shipping
Product-specific conditions are confirmed before order.


