Sodium fluoride

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Sodium fluoride
Sodium fluoride
Sample of sodium fluoride, AR grade
Names
Pronunciation /ˌsoʊdiəm ˈflʊəraɪd/[1]
IUPAC name
Sodium fluoride
Other names
Florocid
Identifiers
ChEBI
ChEMBL
ChemSpider
ECHA InfoCard
 100.028.789 Edit this at Wikidata
EC Number
  • 231-667-8
KEGG
RTECS number
  • WB0350000
UNII
UN number 1690
  • InChI=1S/FH.Na/h1H;/q;+1/p-1 checkY
    Key: PUZPDOWCWNUUKD-UHFFFAOYSA-M checkY
  • InChI=1/FH.Na/h1H;/q;+1/p-1
    Key: PUZPDOWCWNUUKD-REWHXWOFAH
Properties
NaF
Molar mass 41.988173 g/mol
Appearance White to greenish solid
Odor odorless
Density 2.558 g/cm3
Melting point 993 °C (1,819 °F; 1,266 K)
Boiling point 1,704 °C (3,099 °F; 1,977 K)
36.4 g/L (0 °C);
40.4 g/L (20 °C);
50.5 g/L (100 °C)[2]
Solubility slightly soluble in HF, ammonia
negligible in alcohol, acetone, SO2, dimethylformamide
Vapor pressure 1 mmHg @ 1077 °C[3]
Acidity (pKa) 3,20 (weak base, see HF)
−16.4·10−6 cm3/mol
1.3252
Structure
Cubic
a = 462 pm
Octahedral
Thermochemistry
46.82 J/(mol K)
51.3 J/(mol K)
Std enthalpy of
formation
(ΔfH⦵298)
 -573.6 kJ/mol
-543.3 kJ/mol
Pharmacology
A01AA01 (WHO) A12CD01 (WHO),
V09IX06 (WHO) (18F)
Hazards
GHS labelling:
Acute Toxicity GHS07: Exclamation mark GHS08: Health hazard
Danger
H301, H315, H319, H335[4]
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 3: Short exposure could cause serious temporary or residual injury. E.g. chlorine gasFlammability 0: Will not burn. E.g. waterInstability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no code
3
0
0
Flash point Non-flammable
Lethal dose or concentration (LD, LC):
52–130 mg/kg (oral in rats, mice, rabbits)[6]
NIOSH (US health exposure limits):
PEL (Permissible)
 TWA 2.5 mg/m3[5]
REL (Recommended)
 TWA 2.5 mg/m3[5]
IDLH
(Immediate danger)
 250 mg/m3 (as F)[5]
Safety data sheet (SDS) [4]
Related compounds
Other anions
 Sodium chloride
Sodium bromide
Sodium iodide
Sodium astatide
Other cations
 Lithium fluoride
Potassium fluoride
Rubidium fluoride
Caesium fluoride
Francium fluoride
Related compounds
 TASF reagent
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
☒N verify (what is checkY☒N ?)

Sodium fluoride (NaF) is an

fluoridation of drinking water to prevent tooth decay, and in toothpastes and topical pharmaceuticals for the same purpose. In 2021, it was the 291st most commonly prescribed medication in the United States, with more than 600,000 prescriptions.[7][8] It is also used in metallurgy and in medical imaging
.

Uses

Sodium fluoride is sold in tablets for cavity prevention

Dental caries

See also: Fluoride therapy and Water fluoridation

Fluoride salts are often added to municipal drinking water (as well as to certain food products in some countries) for the purpose of maintaining dental health. The fluoride enhances the strength of teeth by the formation of fluorapatite, a naturally occurring component of tooth enamel.[9][10][11] Although sodium fluoride is used to fluoridate water and is the standard by which other water-fluoridation compounds are gauged, hexafluorosilicic acid (H2SiF6) and its salt sodium hexafluorosilicate (Na2SiF6) are more commonly used additives in the United States.[12]

Osteoporosis

Fluoride supplementation has been extensively studied for the treatment of postmenopausal osteoporosis. This supplementation does not appear to be effective; even though sodium fluoride increases bone density, it does not decrease the risk of fractures.[13][14]

Medical imaging

In medical imaging,

SPECT systems, PET offers more sensitivity and spatial resolution. Fluorine-18 has a half-life of 110 min, which requires it to be used promptly once produced; this logistical limitation hampered its adoption in the face of the more convenient technetium-99m-labelled radiopharmaceuticals. However fluorine-18 is generally considered to be a superior radiopharmaceutical for skeletal imaging. In particular it has a high and rapid bone uptake accompanied by very rapid blood clearance, which results in a high bone-to-background ratio in a short time.[16] Additionally the annihilation photons produced by decay of 18F have a high energy of 511 keV compared to the 140 keV photons of 99mTc.[17]

Chemistry

Sodium fluoride has a variety of specialty chemical applications in synthesis and extractive

Electrofluorination, Fowler process
).

Biology

Sodium fluoride is sometimes added at relatively high concentrations (~20 mM) to protein lysis buffers in order to inhibit endogenous

Sodium pyrophosphate and Sodium orthovanadate are also used for this purpose.[20]

Other uses

Sodium fluoride is used as a cleaning agent (e.g., as a "laundry sour").[21]

Sodium fluoride can be used in a nuclear

molten salt reactor
.

Over a century ago,[

oxidative metabolism.[23]

Safety

See also:
Fluoride poisoning

The lethal dose for a 70 kg (154 lb) human is estimated at 5–10 g.[21]

Fluorides, particularly aqueous solutions of sodium fluoride, are rapidly and quite extensively absorbed by the human body.[24]

Fluorides interfere with electron transport and

arrhythmias due to profound hypocalcemia. Chronic over-absorption can cause hardening of bones, calcification of ligaments, and buildup on teeth. Fluoride can cause irritation or corrosion to eyes, skin, and nasal membranes.[25]

Sodium fluoride is classed as toxic by both inhalation (of dusts or aerosols) and ingestion.[26] In high enough doses, it has been shown to affect the heart and circulatory system. For occupational exposures, the Occupational Safety and Health Administration and the National Institute for Occupational Safety and Health have established occupational exposure limits at 2.5 mg/m3 over an eight-hour time-weighted average.[27]

In the higher doses used to treat

mottling of the teeth (fluorosis) and an exposure of 1.7 ppm will produce mottling in 30%–50% of patients.[24]

Chemical structure

Sodium fluoride is an inorganic

ionic compound, dissolving in water to give separated Na+ and F− ions. Like sodium chloride, it crystallizes in a cubic motif where both Na+ and F− occupy octahedral coordination sites;[30][31] its lattice spacing, approximately 462 pm
, is smaller than that of sodium chloride (564 pm).

Occurrence

The mineral form of NaF, villiaumite, is moderately rare. It is known from plutonic nepheline syenite rocks.[32]

Production

NaF is prepared by neutralizing

phosphate rock during the production of superphosphate fertilizer. Neutralizing agents include sodium hydroxide and sodium carbonate. Alcohols are sometimes used to precipitate the NaF:[21]

HF + NaOH → NaF + H2O

From solutions containing HF, sodium fluoride precipitates as the bifluoride salt sodium bifluoride (NaHF2). Heating the latter releases HF and gives NaF.

HF + NaF ⇌ NaHF2

In a 1986 report, the annual worldwide consumption of NaF was estimated to be several million tonnes.[21]

See also

Wikimedia Commons has media related to Sodium fluoride.

References

  1. ISBN 978-1-4058-8118-0. According to this source, an alternative pronunciation of the second word is /ˈflɔːraɪd/ and, in the UK, also /ˈfluːəraɪd/
    .
  2. ISBN 978-1-4398-5511-9
    .
  3. ^ Lewis, R.J. Sax's Dangerous Properties of Industrial Materials. 10th ed. Volumes 1–3 New York, NY: John Wiley & Sons Inc., 1999., p. 3248
  4. ^ a b Sigma-Aldrich Co., Sodium Fluoride.
  5. ^ a b c NIOSH Pocket Guide to Chemical Hazards. "#0563". National Institute for Occupational Safety and Health (NIOSH).
  6. ISBN 978-1-903996-65-2
  7. ^ "The Top 300 of 2021". ClinCalc. Archived from the original on 15 January 2024. Retrieved 14 January 2024.
  8. ^ "Sodium Fluoride – Drug Usage Statistics". ClinCalc. Retrieved 14 January 2024.
  9. ISBN 978-3-8055-4341-5. {{cite book}}: |first1= has generic name (help)CS1 maint: multiple names: authors list (link
    )
  10. ISBN 978-0-471-31266-6
    .
  11. S2CID 204616785
    .
  12. ^ Division of Oral Health, National Center for Prevention Services, CDC (1993), Fluoridation census 1992 (PDF), retrieved 2008-12-29.{{citation}}: CS1 maint: multiple names: authors list (link)
  13. PMID 11034769
    .
  14. S2CID 25890845
    .
  15. PMID 5059349
    .
  16. PMID 25750032
    .
  17. PMID 18077529
    .
  18. ISBN 978-0-471-93623-7
  19. PMID 3355162
    .
  20. ^ "Overview of Protease and Phosphatase Inhibition for Protein Preparation - US". Thermo Fisher Scientific. 2017-05-10. Retrieved 2023-02-03.
  21. ^
    ISBN 978-3527306732
    .
  22. ISBN 978-0-12-802979-4
    .
  23. ^ Metcalf, Robert L. (2007), "Insect Control", Ullmann's Encyclopedia of Industrial Chemistry (7th ed.), Wiley, p. 9
  24. ^ a b Kapp, Robert (2005), "Fluorine", Encyclopedia of Toxicology, vol. 2 (2nd ed.), Elsevier, pp. 343–346
  25. ^ Greene Shepherd (2005), "Fluoride", Encyclopedia of Toxicology, vol. 2 (2nd ed.), Elsevier, pp. 342–343
  26. ^ NaF MSDS. hazard.com
  27. ^ CDC – NIOSH Pocket Guide to Chemical Hazards
  28. PMID 8837545
    .
  29. PMID 18584000
    .
  30. ISBN 978-0-19-855370-0
  31. ^ "Chemical and physical information", Toxicological profile for fluorides, hydrogen fluoride, and fluorine (PDF), Agency for Toxic Substances and Disease Registry (ATDSR), September 2003, p. 187, retrieved 2008-11-01
  32. ^ Mineral Handbook (PDF), Mineral Data Publishing, 2005.
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