Acids & Salts Available — Bulk Only

Boric Acid (Orthoboric Acid)

CAS 10043-35-3 · Formula BH3O3 · MW 61.84 g/mol

A primary boron feedstock bridging glassmaking, fluxing, and flame-retardant treatments. It is used in the manufacture of borosilicate glass and glass fiber, as a flux in metallurgy and soldering, as a flame retardant for cellulose insulation and textiles, and as a wood preservative.

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HS Code
2810.00
At a Glance
Material Family
Acids & Salts
Record Type
Pure compound
Primary Role
Biocidal Action · pH Adjustment
Functional Roles
BORIC ACID
ANTIMICROBIALBUFFERINGDENATURANT
Applications & Use Cases
  • Glass and glass fiber: Boron source for borosilicate glass and fiberglass.
  • Metallurgical flux: Flux for soldering and brazing.
  • Flame retardant: Treats cellulose insulation and textiles.
  • Wood preservation: Used to protect and weatherproof wood.
  • Electroplating: Buffer additive for nickel plating baths.
Physical Properties
Physical Description
Colourless, odourless, transparent crystals or white granules or powder; slightly unctuous to the touch; occurs in nature as the mineral sassolite
Appearance
Colorless, transparent crystals or white granules or powder
Odor
Odorless
Taste
Faintly bitter
Boiling Point
300 °C at 760 mmHg (decomposes)
Melting Point
171 °C
Solubility
Water solubility: 2.52% at 0 °C; 3.49% at 10 °C; 4.72% at 20 °C; 6.23% at 30 °C; 8.08% at 40 °C; 10.27% at 50 °C; 12.97% at 60 °C; 15.75% at 70 °C; 19.10% at 80 °C; 23.27% at 90 °C; 27.53% at 100 °C
Density
1.435 at 20 °C
Vapor Pressure
1.6X10-6 mm Hg at 25 °C (2.136X10-4 Pa); log P (in Pa) = 26.83
LogP
log Kow = 0.175
pH
3,8-4,8 (3,3 % aqueous solution)
Refractive Index
Index of refraction: 1.337, 1.461, 1.462
Dissociation Constants
Ka = 5.80X10-10 at 25 °C (pKa = 9.24)
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.

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HS / Tariff Classification
Harmonized System (HS) Code — 6-digit international heading
2810 . 00
Chapter 28
Inorganic chemicals; compounds of precious metals and rare-earth metals
Heading 28.10
Internationally harmonized (WCO HS)
Subheading 2810.00
6-digit international code — national tariff line adds further digits
Chemical Identity
CAS Number
10043-35-3
Molecular Formula
BH3O3
Molecular Weight
61.84 g/mol
IUPAC Name
boric acid
INCI Name
BORIC ACID
PubChem CID
InChI Key
KGBXLFKZBHKPEV-UHFFFAOYSA-N
Synonyms & Trade Names
BORIC ACID Orthoboric acid Boracic acid Borofax Boron hydroxide Boric acid (H3BO3) Boron trihydroxide Basilit B Three Elephant Boric acid (BH3O3) Trihydroxyborane Trihydroxyborone Flea Prufe Super Flea Eliminator Orthoborsaeure Borsaeure Borsaure Orthoboric acid (B(OH)3) NCI-C56417 Dr.'s 1 Flea Terminator DT
Full Description

Boric acid (CAS 10043-35-3, H3BO3) is a weak inorganic acid and boron source. It is used in the manufacture of borosilicate glass and glass fiber, as a flux in metallurgy and soldering, as a flame retardant for cellulose insulation and textiles, and as a wood preservative.

Frequently Asked Questions

What is boric acid commonly used for?

Boric acid (CAS 10043-35-3, H3BO3) is a boron source and weak inorganic acid used industrially in borosilicate glass and glass-fiber manufacture, as a flux for soldering and brazing, as a flame retardant for cellulose insulation and textiles, as a wood preservative, and as a buffer additive in nickel electroplating baths.

What is the chemical formula of boric acid?

Boric acid has the formula H3BO3 (also written BH3O3) and CAS number 10043-35-3. It is a weak inorganic acid and one of the principal industrial sources of boron.

Why is boric acid used in glass and metallurgy?

In glass manufacture boric acid supplies boron oxide for borosilicate glass and glass fiber, lowering thermal expansion. In metallurgy it acts as a flux during soldering and brazing, helping clean metal surfaces and protect them from oxidation during heating.

What grade and packaging is bulk boric acid available in?

RawSource supplies boric acid in industrial bulk packaging for glass, foundry, coatings, and electroplating customers. Specify your intended application and required quantity to receive a grade recommendation; a CoA and SDS accompany each shipment.

What is the cost of bulk boric acid?

Boric acid pricing depends on grade, order volume, and packaging and is quoted per order rather than as a fixed price. Submit a bulk RFQ with your target quantity to get current pricing and lead time.

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.