- What it is. This sodium fluoride is an ACS reagent-grade white crystalline powder, supplied in a 1 lb size. It is a high-purity fluoride salt used to prepare fluoride standards, inhibit enzymes, and support analytical and industrial applications.
- What ACS grade guarantees. ACS reagent sodium fluoride limits insoluble matter (0.01%), free acid and free alkali, sodium fluorosilicate (0.1%), chloride (0.003%), sulfate (0.01%), sulfite (0.005%), heavy metals (0.001%), and iron (0.002%), with an assay of at least 99.5% in comparable ACS products.
- Chemical identity. Sodium fluoride (CAS 7681-49-4, NaF, 41.99 g/mol) is a colorless to white crystalline salt with a density of about 2.7 to 2.8 g/cm³ and a water solubility of about 42 g per liter.
- Fluoride standards. ACS sodium fluoride is the usual source for preparing fluoride standards for ion-selective electrode and colorimetric fluoride analysis. A 1000 mg/L fluoride stock requires about 2.210 g of dried NaF per liter (calculated). Lab Pro also stocks a ready-made Fluoride Standard, 1 mg/L (ppm), 500 mL.
- Biochemistry. Sodium fluoride inhibits phosphatases and enolase, so it is added to lysis buffers to preserve protein phosphorylation and to blood collection tubes to stop glycolysis in glucose samples.
- Other uses. Sodium fluoride is used in water fluoridation chemistry, toothpaste and dental formulations, metal surface treatment and fluxes, glass etching mixtures, and wood preservation.
- Toxicity. Sodium fluoride is toxic if swallowed, and it irritates the skin and eyes. When it contacts strong acids, it releases hydrogen fluoride. Handle it with gloves and eye protection, avoid creating dust, and keep it away from acids.
- Preparing standards safely. When preparing fluoride stock solutions, weigh the salt in a ventilated area, avoid dust, and dissolve it in plastic labware. Label standards with concentration and date, and keep them away from acids, which could release hydrogen fluoride.
- Compatible labware. Fluoride solutions slowly attack glass, especially when acidic. Store fluoride standards and solutions in polyethylene or polypropylene containers rather than glass.
Technical Specifications
| Chemical Name | Sodium fluoride |
| CAS Number | 7681-49-4 |
| EC Number | 231-667-8 |
| Synonyms | NaF, natrium fluoride |
| Formula | NaF |
| Molecular Weight | 41.99 g/mol |
| Grade | ACS reagent |
| Assay (comparable ACS products) | 99.5% min |
| Insoluble Matter | 0.01% max |
| Free Acid (as HF) | 0.05% max |
| Free Alkali (as NaOH) | 0.04% max |
| Sodium Fluorosilicate (Na2SiF6) | 0.1% max |
| Chloride (Cl) | 0.003% max |
| Sulfate (SO4) | 0.01% max |
| Sulfite (SO3) | 0.005% max |
| Heavy Metals (as Pb) | 0.001% max |
| Iron (Fe) | 0.002% max |
| Potassium (K) | 0.02% max |
| Loss on Drying (150 °C) | 0.2% max |
| Water Solubility | About 42 g/L |
| Density | About 2.7 g/cm³ |
| NaF for 1000 mg/L F⁻ | About 2.210 g/L (calculated) |
| Hazard Profile | Toxic if swallowed; skin and eye irritant; releases HF with acids (confirm on SDS) |
| DOT (typical) | UN1690, Sodium fluoride, solid, Class 6.1, PG III (confirm on SDS) |
| Package Size | 1 lb |
Applications / Common Uses
- Fluoride standards: Prepares stock standards for ISE and colorimetric analysis.
- Phosphatase inhibition: Preserves phosphorylation in lysis buffers.
- Glycolysis inhibition: Stabilizes glucose in blood samples.
- Dental and fluoridation chemistry: Supports formulation and research.
- Metal treatment: Serves in fluxes and surface treatment.
Storage, Handling & Shipping
Caution: Sodium fluoride is toxic if swallowed and irritates the skin and eyes. Contact with strong acids releases hydrogen fluoride. Wear gloves and eye protection, avoid creating dust, and keep it away from acids.
Store in a tightly closed container in a cool, dry, secure location away from acids and food. Keep fluoride solutions in polyethylene or polypropylene containers, since fluoride slowly attacks glass.
- Incompatible materials: Strong acids (release HF), glass and silicates (slowly attacked), and strong oxidizers.
- Personal protection: Safety glasses, nitrile gloves, and dust control.
- Spill response: Sweep up without raising dust and place in a closed container for disposal.
- First aid: Ingestion: seek immediate medical attention. Eyes or skin: Rinse with water for several minutes.
Related Categories & Services
- Shop ACS Grade Laboratory Chemicals for related products in this category.
- Explore Inorganic Chemicals and Buffers, Standards & Solutions.
- Vendor Managed Inventory (VMI) Program: Lab Pro can stock, track, and replenish this item on site so it never runs out. Contact info@labproinc.com or 888-452-2776 to set up a VMI assessment.
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FAQs
How do I prepare a 1000 mg/L fluoride standard?
Dry ACS sodium fluoride, cool it in a desiccator, and dissolve 2.210 g in deionized water, diluting to 1 liter in a volumetric flask. Transfer the standard to a polyethylene container for storage, since fluoride slowly attacks glass, and label it with the preparation date.
Why is sodium fluoride added to lysis buffers?
Sodium fluoride inhibits serine and threonine phosphatases, enzymes that remove phosphate groups from proteins. Adding it to lysis buffers preserves proteins' phosphorylation state during extraction, which is essential for studying signaling pathways and phosphoproteins. It is commonly combined with sodium orthovanadate, which inhibits tyrosine phosphatases, for broader protection of phosphorylated proteins.
Why are some blood tubes treated with sodium fluoride?
Sodium fluoride inhibits enolase, an enzyme in glycolysis. In blood collection tubes, it stops red and white blood cells from consuming glucose after the sample is drawn, so measured glucose reflects the level at collection rather than falling over time. These tubes usually have gray stoppers.
Is sodium fluoride toxic?
Yes. Sodium fluoride is toxic if swallowed and irritates the skin and eyes. When it comes into contact with strong acids, it releases hydrogen fluoride. Handle it with gloves and eye protection, avoid creating dust, store it securely away from food, and seek medical attention after any ingestion.
Why store fluoride solutions in plastic?
Fluoride reacts slowly with silica in glass, especially in acidic solution, which can etch the container and change the fluoride concentration. Polyethylene and polypropylene containers do not react with fluoride, so they maintain the stated concentration. Label all fluoride containers clearly, and keep them separate from food and drink areas.
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