A high-temperature, halogen-free mineral flame retardant that also neutralizes process acids and treats effluent. In polymers it serves as a halogen-free flame retardant and smoke suppressant with higher thermal stability than aluminum hydroxide.
▸Flame retardant: Halogen-free flame retardant and smoke suppressant for polymers.
▸Acid neutralization: Neutralizing agent for acids in the chemical industry.
▸Wastewater treatment: pH adjustment and treatment in wastewater.
▸Chemical intermediate: Raw material for magnesium metal and magnesium compounds.
▸Process additive: Additive in residual fuel oil and sulfite pulp processing.
Physical Properties
Physical Description
White odorless solid; Colorless or white solid; Hygroscopic in powdered form; White odorless powder; Practically insoluble in water
Appearance
White, hexagonal crystals
Odor
Odorless
Melting Point
350 °C (decomposes)
Solubility
White, friable masses or bulky, white powder; at about 700 °C is converted to MgO; sol in about 3,300 parts CO2-free water; more sol in water containing CO2; sol in dilute acids with effervescence; insol in alcohol /Magnesium carbonate hydroxide/
Density
2.36 g/mL
pH
pH = 9.5-10.5 (aqueous slurry)
Refractive Index
Index of refraction: 1.559, 1.580
Safety & Handling
Full SDS available on request
A grade-specific Safety Data Sheet (SDS) — with the complete hazard classification, handling precautions, and transport information — is supplied with every shipment and available on request. Confirm all safety and regulatory details against the SDS for your specific grade.
Magnesium hydroxide (MDH, CAS 1309-42-8) is an inorganic compound, occurring naturally as brucite, used as a flame retardant, acid neutralizer, and chemical intermediate. In polymers it serves as a halogen-free flame retardant and smoke suppressant with higher thermal stability than aluminum hydroxide. It is also used to neutralize acids in the chemical industry and in wastewater treatment.
Frequently Asked Questions
What is magnesium hydroxide used for?
Magnesium hydroxide (MDH, CAS 1309-42-8) is used as a halogen-free flame retardant and smoke suppressant in polymers, as an acid-neutralizing agent in the chemical industry, and for pH adjustment in wastewater treatment. It also serves as a chemical intermediate for magnesium metal and compounds.
What is the name of Mg(OH)2?
Mg(OH)2 is magnesium hydroxide (CAS 1309-42-8, formula H2MgO2), which occurs naturally as the mineral brucite. It is sometimes abbreviated MDH in flame-retardant applications.
Why is magnesium hydroxide used as a flame retardant?
As a halogen-free flame retardant and smoke suppressant, magnesium hydroxide offers higher thermal stability than aluminum hydroxide, making it suitable for polymers processed at elevated temperatures. It decomposes endothermically to release water and form a protective oxide layer.
What is the HS code for magnesium hydroxide?
Magnesium hydroxide classifies under HS 2816.10. Use this code for customs documentation and verify against your jurisdiction's current tariff schedule.
How is bulk magnesium hydroxide supplied and priced?
It is supplied as a powder in bulk for flame-retardant, acid-neutralization, wastewater, and intermediate applications. Pricing depends on grade, volume, and packaging; request a bulk quote with CoA and SDS for your target quantity.
Disclaimer. Information on this page — including properties, identifiers, hazard, transport (DOT/UN) and tariff (HS) classifications, and applications — is provided for general reference and is compiled from authoritative public sources (e.g. PubChem/ECHA, 49 CFR 172.101, the Harmonized Tariff Schedule). Values are typical and are not a guaranteed specification; the Certificate of Analysis (CoA) for the lot purchased governs. Products are sold for industrial and professional use only. Nothing here is a medical, health, or efficacy claim or advice. Always consult the current Safety Data Sheet (SDS) before handling, storage, transport or disposal, and confirm regulatory status, classification and suitability for your application and jurisdiction. Hazard, transport and tariff classifications must be verified for your specific shipment. RawSource makes no warranty, express or implied, and assumes no liability for use of this information. Trademarks. Third-party trademarks and brand names are the property of their respective owners; any reference is nominative — used only to identify a comparable product — and does not imply affiliation with, sponsorship by, or endorsement by the trademark owner.
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