Hydrofluorosilicic Acid 23% (HFS)

Product Overview

Hydrofluorosilicic Acid 23% (HFS) is a colorless, aqueous solution of fluorosilicic acid designed for precise fluoride delivery in water treatment and industrial fluoride applications. This solution provides fluoride ions for dental cavity prevention programs and serves as a versatile precursor in the synthesis of fluorinated organic and inorganic compounds. The product is formulated to deliver a typical assay of 23% with strict control of color (APHA/Hazen color ≤ 8, typical 4) to ensure compatibility with downstream processes and regulatory requirements. The solution exhibits a density near 1.15 g/mL at 25°C and a refractive index of 1.335, supporting consistent dosing strategies in both municipal and industrial settings. All handling and dosing strategies align with ACS Reagent Grade and USP-NF Monograph expectations to support high-purity fluoride delivery in demanding environments.

In addition to water fluoridation, HFS is employed in chemical synthesis as a source of fluorine-containing fragments and in corrosion-inhibition contexts where controlled fluoride activity is beneficial. Maintained under controlled storage conditions to preserve fluoride concentration and reduce variability, the material is supplied in HDPE-compatible packaging suitable for transport and on-site storage. This product is non-flammable and is accompanied by a Safety Data Sheet (SDS) detailing hazard classifications and emergency procedures consistent with industry best practices.

Key Properties

• Appearance: Colorless liquid
• Odor: Slightly pungent
• Chemical Formula: H₂SiF₆
• Molecular Weight: 144.28 g/mol
• Boiling Point: 100°C
• Density (25°C): 1.15 g/mL
• Specific Gravity (20°C): 1.15 – 1.20 (typical 1.175)
• Water Solubility: Soluble in water
• Refractive Index (20°C): 1.335
• Assay (wt %): 22.5 – 23.5% (typical 23%), Titration with standardized NaOH
• Available Chlorine (wt %): 0.2 – 1.2% (typical 0.8%), Iodometric titration
• pH (target/application dependent): Controlled by formulation; typical ranges align with fluoride delivery requirements
• Residue After Ignition: ≤ 0.1% (typical 0.05%), gravimetric analysis

Common Applications

• Application Category: Water Fluoridation – Used to add fluoride to drinking water to enhance dental health outcomes; dosing is calibrated against assay and specific gravity to achieve target fluoride concentrations per municipal guidelines.
• Application Category: Chemical Synthesis – Serves as a fluoride source in the synthesis of fluorinated organic and inorganic compounds, enabling access to fluorinated intermediates with high purity.
• Application Category: Corrosion Inhibition – Integrated into processing streams to leverage fluoride-based protection in specific metal-finishing environments.
• Application Category: pH Adjustment – Applied in water treatment and environmental management to stabilize pH while delivering fluoride ion activity.
• Application Category: Electroplating – Utilized in electroplating baths to influence adhesion, finish quality, and barrier properties in metal coatings.
• Application Category: Catalyst Preparation – Used in certain catalytic systems where fluoride ligands modulate activity and selectivity.

Safety Precautions

Handle and store in accordance with SDS guidance: store in a cool, dry place away from direct sunlight in HDPE containers; ensure adequate ventilation; wear appropriate PPE including chemical-resistant gloves, goggles, and protective clothing. Avoid contact with strong bases and oxidizing agents; implement spill containment and emergency wash stations in the area of use.

In the event of exposure or release, consult the SDS for first-aid guidance: skin and eye contact require immediate flushing with water for extended periods; if inhaled, move to fresh air and seek medical attention; for ingestion, rinse the mouth and do not induce vomiting and seek medical care. The product is classified with GHS labels including Skin Corr. 1A, Eye Dam. 1, and Aquatic Acute 1; follow established emergency response procedures for corrosive and aquatic toxicants. Transport as UN 1760, Corrosive liquid, n.o.s., Class 8, PG II.

Benefits

✔ Precise Fluoride Delivery – Consistent assay and controlled fluoride content support reliable dosing in water treatment and fluorination processes.
✔ Standards-Compliant Purity – Meets ACS Reagent Grade and USP-NF Monograph expectations for high-purity fluorosilicic acid formulations.
✔ Analytical Traceability – Comprehensive specification suite (IC, ICP-OES, ICP-MS based) enables traceable quality control and regulatory compliance.
✔ Storage and Handling Robustness – Stable formulation with clear storage guidelines, reducing variability in field applications.