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. Texas-Chem 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
Low acute toxicity — use standard industrial hygiene practices. Avoid dust inhalation when handling powder. Always consult the current Safety Data Sheet before handling.
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 Texas-Chem?
- 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
Boric Acid vs. Alternatives
Boric acid is a mild inorganic acid with broad applications in glass, agriculture, and pest control. Here's how it compares to related acids.
| Attribute | Boric Acid | Phosphoric Acid | Citric Acid |
|---|---|---|---|
| pKa | 9.24 (very weak acid) | 2.15 (first) | 3.13 (first) |
| Physical State | White crystalline powder | Colorless liquid or solid | White crystalline solid |
| Primary Use | Glass/fiberglass, agriculture, pest control | Fertilizers, metal treatment, food | Food, pharma, cleaning |
| Toxicity | Low — mild antiseptic | Moderate — corrosive at high conc. | Very low — food-safe |
| Solubility in Water | 57 g/L at 25 °C | Fully miscible | 592 g/L at 20 °C |
Industries We Supply Boric Acid To
Glass & Fiberglass Manufacturing
Boric acid is a key flux and stabilizer in borosilicate glass and fiberglass insulation production, improving thermal and chemical resistance.
Boric Acid supply in Houston, TXAgriculture & Micronutrients
Used as a boron micronutrient supplement in fertilizers for crops grown in boron-deficient soils across Texas agricultural regions.
Boric Acid supply in Lubbock, TXWood Preservation
Borate-based wood preservatives protect structural lumber and timber from fungal decay and insect damage in construction applications.
Boric Acid supply in Fort Worth, TXNuclear & Industrial
Used as a neutron absorber in nuclear reactor coolant systems and as a flame retardant additive in industrial applications.
Boric Acid supply in Beaumont, TX