CAS 10043-35-3 · Inorganic Acid
Boric Acid
Orthoboric Acid · H₃BO₃ · MW 61.83 g/mol
A mild, water-soluble inorganic acid with a broad range of industrial, agricultural, and pharmaceutical applications. Boric acid's unique Lewis acid chemistry, low toxicity profile, and versatile reactivity make it a critical input for glass manufacturing, electroplating, wood preservation, and micronutrient fertilization. CFPT supplies boric acid in bags, drums, and super sacks.
Formula
H₃BO₃
Melting Point
171 °C
Solubility
57 g/L at 20 °C
Pack Sizes
Bags · Drums · Super Sacks
Structural Formula
Trigonal planar boron center — Lewis acid with three hydroxyl groups
Safety & Regulatory
- NFPA Health
- 2 — Moderate hazard
- NFPA Flammability
- 0 — Non-flammable
- NFPA Reactivity
- 0 — Stable
- OSHA PEL (TWA)
- 15 mg/m³ (total dust)
- ACGIH TLV (TWA)
- 2 mg/m³ (inhalable fraction)
- DOT Hazard Class
- Not regulated
- UN Number
- Not assigned
- Packing Group
- N/A
- SARA 313
- Not listed
SDS available upon request.
Grades & Packaging
Available Grades
Pack Sizes
Physical & Chemical Properties
| Molecular Formula | H₃BO₃ |
| Molecular Weight | 61.83 g/mol |
| CAS Number | 10043-35-3 |
| Appearance | White crystalline powder or granules |
| Melting Point | 171 °C (340 °F) |
| Boiling Point | 300 °C (572 °F) — dehydrates to B₂O₃ |
| Density | 1.435 g/cm³ at 20 °C |
| Solubility in Water | 57 g/L at 20 °C; 275 g/L at 100 °C |
| pH (0.1 M solution) | ~5.1 — Weakly acidic |
| Vapor Pressure | Negligible at 20 °C |
| Flash Point | Non-flammable solid |
| pKa | 9.24 (Lewis acid mechanism) |
Industrial Applications
Glass & Fiberglass Manufacturing
Essential flux and network modifier in borosilicate glass (Pyrex), optical glass, and fiberglass insulation. Lowers melting temperature, improves thermal shock resistance, and reduces the coefficient of thermal expansion.
Electroplating & Metal Finishing
pH buffer in nickel, copper, and tin electroplating baths. Maintains stable bath chemistry, prevents hydrogen embrittlement, and improves deposit quality and brightness.
Wood Preservation & Pest Control
Broad-spectrum biocide for wood treatment against fungi, termites, and wood-boring insects. Low mammalian toxicity and long service life make it preferred for structural lumber and utility poles.
Flame Retardants
Incorporated into cellulosic materials, textiles, and insulation products to impart flame retardancy. Decomposes endothermically at elevated temperatures, releasing water vapor that dilutes combustible gases.
Pharmaceuticals & Antiseptics
USP/FCC grade used in ophthalmic solutions, ear drops, and topical antiseptic formulations. Mild bacteriostatic and fungistatic activity at low concentrations.
Fertilizers & Agriculture
Micronutrient boron source for boron-deficient soils. Critical for cell wall formation, pollen germination, and sugar transport in crops such as alfalfa, cotton, and sugar beets.
Why Source Boric Acid from CFPT?
- 35+ years supplying industrial acids and specialty chemicals to Texas industry
- Industrial, Technical, ACS, and USP/FCC grades stocked for diverse applications
- Flexible packaging from 50-lb bags to super sacks and bulk
- Competitive pricing backed by top-tier producer relationships
- Technical support and SDS documentation with every order
- Same-day quotes for standard quantities