Molekula
Magnesium hydroxide
Supplying 4,500+ customers in over 80 countries
ISO 9001:2015 & ISO 14001:2015 certified · Supplying laboratories and industry since 2000 · Listed pack sizes are a starting point — we manufacture, source and repack to the quantity you need
Magnesium hydroxide is a white, crystalline powder used as an antacid, laxative, and flame retardant. It is also employed in water treatment and as a neutralizing agent. Available in powder form with a molecular weight of 58.32 g/mol, it has a CAS number of 1309-42-8 and is stable at ambient storage conditions. Molekula supplies Magnesium hydroxide from research to bulk quantities with full documentation and ISO 9001:2015 traceability.
Example image for illustration only. Other packaging and pack sizes are available.
Pricing & pack sizes
These pack sizes aren't a limit. Molekula manufactures, sources and repacks to order — if you need 500 kg and only see 1 kg listed, . We quote from grams to multi-tonne.
Need a different size? Add the nearest pack and change the size in your basket — we price it at the same rate per unit.
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100 g — £30.90 per pack ex VAT · £37.08 inc. VAT
Need a different quantity or pack?
Tell us how much you need and when — drums, IBCs, sacks or a one-off bulk lot. We'll manufacture or source it and come back with a price.
Prices exclude VAT/sales tax and shipping.
Specifications
| Property | Value |
|---|---|
| Appearance | White to off-white powder |
| Water | ≤0.3% |
| Loss on Drying | ≤31% |
| Chloride (Cl-) | ≤0.08% |
| Assay | ≥99.0% |
| Iron (Fe) | ≤0.006% |
| Calcium (Ca) | ≤0.03% |
| Manganese (Mn) | ≤0.005% |
| Aluminium (Al) | ≤0.005% |
| Silicon (Si) | ≤0.032% |
Storage & handling
| Property | Value |
|---|---|
| Storage Temperature | Ambient |
| Acidity | Base |
Literature values
Published physical properties of the substance, not batch specifications.
| Property | Value |
|---|---|
| Appearance | White, hexagonal crystals |
| Odour | Odorless |
| Melting Point | 350 °C (decomposes) |
| Density | 2.36 g/cm³ |
| Solubility (other solvents) | Soluble in dilute acids |
| Refractive Index | 1.559 |
Source: PubChem CID 73981 (HSDB)
Identification
| Property | Value |
|---|---|
| SKU | 65551228 |
| CAS Number | 1309-42-8 |
| IUPAC Name | magnesium dihydroxide |
| Molecular Formula | Mg(OH)2 |
| Molecular Weight | 58.32 |
| Exact Mass | 57.9905 |
| SMILES | [OH-].[OH-].[Mg+2] |
| InChIKey | VTHJTEIRLNZDEV-UHFFFAOYSA-L |
| InChI | InChI=1S/Mg.2H2O/h;2*1H2/q+2;;/p-2 |
| PubChem CID | 73981 |
| REACH Code | Y113 |
| TSCA Listed | Yes |
| HTS Code | 2816.10.00.00 |
| Tariff Code | 2816100000 |
Safety & GHS
Precautionary statements
- P280 Wear protective gloves/protective clothing/eye protection/face protection
Documents
Safety Data Sheets (SDS)
Available in English, French, German, Italian, Portuguese, Spanish.
Certificate of Analysis (CoA) by batch
Enter a lot or batch number to retrieve the CoA for that specific batch. We can generate one from spec data if no PDF is on file.
Synonyms
- INS NO.528
- Magnesii hydroxidum
- Magnesium (as hydroxide)
- Magnesium dihydroxide
- Magnesium hydrate
- Magnesium hydroxide (Mg(OH)2)
- Magnesium(II) hydroxide
- Milk of magnesia
- Phillips magnesia tablets
- Phillips milk of magnesia liquid
Frequently asked questions
What is magnesium hydroxide used for?
Magnesium hydroxide is commonly used as an antacid, laxative, and in water treatment for pH adjustment and heavy metal precipitation.
What is the chemical formula and molecular weight of magnesium hydroxide?
The formula is Mg(OH)2 and the molecular weight is 58.32 g/mol.
How should magnesium hydroxide be stored?
It should be stored at ambient temperature, protected from moisture and contamination.
What grade of magnesium hydroxide does Molekula supply?
Molekula supplies reagent grade magnesium hydroxide suitable for laboratory and industrial applications.
Can Molekula supply magnesium hydroxide in bulk?
Yes, Molekula can supply magnesium hydroxide in bulk quantities—please contact us for pricing and availability.
What documentation comes with a magnesium hydroxide order?
Each order includes a Certificate of Analysis (CoA) and safety data sheet (SDS) upon request.
Ready to order or need a custom pack?
Tell us the product, grade, and quantity — Molekula usually responds within one working day with pricing and lead time.