Skip to Main Content

About Strontium

Strontium Bohr

In 1790 a Scottish physician named Adair Crawford was the first to distinguish strontium-containing minerals from barium minerals. He had examined a supposed barium carbonate sample from the mine at Strontian, Argyllshire and upon finding that the sample lacked the expected chemical properties, proposed that he had found a new “earth”--a novel natural compound that likely contained a previously unknown element. Many of his contemporaries confirmed the results of his experiments and supported his assessment, and the name “strontium” was given to the new element based upon the origins of the source mineral. It was not until 1808 that Sir Humphry Davy succeeded in isolating the pure metal, a difficult task due to strontium’s high reactivity with water and air. He ultimately succeeded using electrolysis of a mixture of mercury and strontium oxides, a method that also allowed him to produce barium and calcium metals for the first time.

Strontium’s earliest industrial use was in the extraction of sugar from sugar beet molasses through a chemical procedure known as the Strontian process. This method is now obsolete, but strontium remains in use primarily due to the unique chemistry of its compounds. Strontium salts typically burn a bright red, and for this strontium compounds, especially strontium nitrate, are included in fireworks, flares, and tracer ammunition. Strontium oxide is used in pottery glazes to replace alternative compounds which contain toxic lead or barium. When added to glass, the same compound increases hardness, strength, and the index of refraction. This produces a higher-quality glass suitable for optical applications. Additionally, strontium glass blocks UV and X-ray radiation, and for this reason is included in cathode ray tube (CRT) display faceplates. This was once one of the largest uses of strontium, before the use of CRT displays began to decline. Strontium ferrite is a ceramic compound used to produce high strength magnets. These magnets are useful for their resistance to corrosion, low density, effectiveness at high-temperatures, and their ability to be very permanently magnetized. They are generally found in small motors, speakers, decorative magnets, and toys.

Strontium additionally has important medical uses resulting from its chemical similarities to calcium. Though not needed in the body, strontium is taken up by the bones just like calcium, and is known to promote calcium uptake, increasing bone density. Strontium ranelate is used as a drug treatment for patients with osteoporosis, and succeeds in strengthening bones and preventing breaks. Additionally, the radioisotope strontium-89 is used to treat pain from metastatic bone cancer, as it will localize to the bones naturally and kill the cancer cells there, stopping the extreme pain caused by tumors growing within the bones. Strontium gels have even been investigated as promoters of bone growth in bone tissue engineering. Strontium chloride also serves a medical function, as it treats tooth sensitivity when included in toothpaste.

Strontium metal is used fairly rarely, but it is added to some aluminum alloys to improve their ability to be cast into detailed structures, and it also finds occasional use as a chemical reagent.

Strontium, like its fellow alkali earths, is highly reactive, and therefore is never found naturally in the form of the pure metal. Its primary mineral deposits are celestite, a strontium sulfate mineral, and strontianite, a carbonate mineral. Though the vast majority of strontium compounds used are derived from the carbonate, celestite is more commonly mined, as it tends to occur more frequently in deposits large enough to exploit economically. Almost all of the strontium extracted is therefore converted from the sulfate to the carbonate. For the rare cases where strontium metal is needed, it is produced by reducing strontium oxide with aluminum.


Sputtering Targets
+ Open All
- Close All

High Purity (99.999%) Strontium (Sr) Sputtering Target Strontium has low tech applications as an additive to flares and pyrotechnics because of the bright crimson flame produced by its salts. It alsoHigh Purity (99.999%) Strontium Oxide (SrO) Powder has many high technology applications because of its high refractive index as a titanate in glass, as a "getter" in electron tubes and as a dopant for numerous perovskite formulations to produce cathodes for oxygen generation or solid oxide fuel cells. Historically the primary use of strontium has been to produce CRT glass for color televisions and computer monitors. Strontium is available as metal and compounds with purities from 99% to 99.999% (ACS grade to ultra-high purity). Elemental or metallic forms include pellets, rod, wire and granules for evaporation source material purposes. Strontium oxide is available in powder and dense pellet form for such uses as optical coating and thin film applications. Oxides tend to be insoluble. Strontium fluorides is an insoluble strontium source for uses in which oxygen is undesirable such as metallurgy, chemical and physical vapor deposition and in some optical coatings. Strontium is also available in soluble forms including chlorides, nitrates and acetates. These compounds can be manufactured as solutions at specified stoichiometries.

Strontium Properties

Strontium (Sr) atomic and molecular weight, atomic number and elemental symbolStrontium is a Block S, Group 2, Period 5 element. The number of electrons in each of Strontium's shells is 2, 8, 18, 8, 2 and its electron configuration is [Kr] 5s2. Strontium Bohr ModelStrontium was discovered by William Cruickshank in 1787 and first isolated by Humphry Davy in 1808. Strontium was named after the Scottish town it was discovered in.

Symbol: Sr
Atomic Number: 38
Atomic Weight: 87.62
Element Category: alkaline earth metal
Group, Period, Block: 2, 5, s
Color: silvery white
Other Names: Stronzio, Estrôncio
Melting Point: 777 °C, 1430.6 °F, 1050.15 K
Boiling Point: 1377 °C, 2510.6 °F, 1650.15 K
Density: 2.54 g/cm3
Liquid Density @ Melting Point: 2.375 g/cm3
Density @ 20°C: 2.6 g/cm3
Density of Solid: 2630 kg/m3
Specific Heat: 0.0719 Cal/g/K @ 25°C
Superconductivity Temperature: N/A
Triple Point: N/A
Critical Point: N/A
Heat of Fusion (kJ·mol-1): 9.16
Heat of Vaporization (kJ·mol-1): 154.4
Heat of Atomization (kJ·mol-1): 164.4
Thermal Conductivity: 0.354 W/cm/K @ 298.2 K
Thermal Expansion: 22.5 µm·m-1·K-1 (25 °C)
Electrical Resistivity: 23.0 nΩ·cm @ 20 °C
Tensile Strength: N/A
Molar Heat Capacity: 26.4 J·mol-1·K-1
Young's Modulus: 15.7 GPa
Shear Modulus: 6.03 GPa
Bulk Modulus: N/A
Poisson Ratio: 0.28
Mohs Hardness: 1.5
Vickers Hardness: N/A
Brinell Hardness: N/A
Speed of Sound: N/A
Pauling Electronegativity: 0.95
Sanderson Electronegativity: 0.72
Allred Rochow Electronegativity: 0.99
Mulliken-Jaffe Electronegativity: 1.00 (sp orbital)
Allen Electronegativity: 0.963
Pauling Electropositivity: 3.05
Reflectivity (%): N/A
Refractive Index: N/A
Electrons: 38
Protons: 38
Neutrons: 50
Electron Configuration: [Kr] 5s2
Atomic Radius: 215 pm
Atomic Radius, non-bonded (Å): 2.49
Covalent Radius: 195±10 pm
Covalent Radius (Å): 0.9
Van der Waals Radius: 249 pm
Oxidation States: 2, 1 (strongly basic oxide)
Phase: Solid
Crystal Structure: face-centered cubic
Magnetic Ordering: paramagnetic
Electron Affinity (kJ·mol-1) 4.63
1st Ionization Energy: 549.48 kJ·mol-1
2nd Ionization Energy: 1064.25 kJ·mol-1
3rd Ionization Energy: 4138.29 kJ·mol-1
CAS Number: 7440-24-6
EC Number: 231-133-4
MDL Number: MFCD00134060
Beilstein Number: N/A
SMILES Identifier: [SrH2]
InChI Identifier: InChI=1S/Sr
PubChem CID: 5359327
ChemSpider ID: 4514263
Earth - Total: 14.5 ppm
Mercury - Total: 1.11 ppm
Venus - Total: 15.2 ppm
Earth - Seawater (Oceans), ppb by weight: 8100
Earth - Seawater (Oceans), ppb by atoms: 570
Earth -  Crust (Crustal Rocks), ppb by weight: 360000
Earth -  Crust (Crustal Rocks), ppb by atoms: 85000
Sun - Total, ppb by weight: 50
Sun - Total, ppb by atoms: 0.7
Stream, ppb by weight: 60
Stream, ppb by atoms: 0.7
Meterorite (Carbonaceous), ppb by weight: 8900
Meterorite (Carbonaceous), ppb by atoms: 2000
Typical Human Body, ppb by weight: 4600
Typical Human Body, ppb by atom: 330
Universe, ppb by weight: 40
Universe, ppb by atom: 0.06
Discovered By: William Cruickshank
Discovery Date: 1787
First Isolation: Humphry Davy (1808)

Health, Safety & Transportation Information for Strontium

The non-radioactive isotopes of Strontium are not toxic. Safety data for Strontium and its compounds can vary widely depending on the form. For potential hazard information, toxicity, and road, sea and air transportation limitations, such as DOT Hazard Class, DOT Number, EU Number, NFPA Health rating and RTECS Class, please see the specific material or compound referenced in the Products tab. The below information applies to elemental (metallic) Strontium.

Safety Data
Signal Word Danger
Hazard Statements H260-H315
Hazard Codes F,Xi
Risk Codes 11-14-36
Safety Precautions 26
RTECS Number UN 3208 4.3/PG 1
Transport Information N/A
WGK Germany 3
Globally Harmonized System of
Classification and Labelling (GHS)
Exclamation Mark-Acute Toxicity Flame-Flammables
Review and Print SDS for Strontium Metal


Date Revised: 05/15/2015
Date Revised: 05/15/2015


Product Name: Strontium Metal

Product Number: All applicable American Elements product codes, e.g. SR-M-02, SR-M-03, SR-M-04, SR-M-05

CAS #: 7440-24-6

Relevant identified uses of the substance: Scientific research and development

Supplier details:
American Elements
1093 Broxton Ave. Suite 2000
Los Angeles, CA 90024
Tel: +1 310-208-0551
Fax: +1 310-208-0351

Emergency telephone number:
Domestic, North America +1 800-424-9300
International +1 703-527-3887


Classification of the substance or mixture in accordance with 29 CFR 1910 (OSHA HCS)
GHS02 Flame
Water-react. 2 H261 In contact with water releases flammable gas.
Hazards not otherwise classified
No information known.
Label elements
GHS label elements
The product is classified and labeled in accordance with 29 CFR 1910 (OSHA HCS)
Hazard pictograms

Flame - GHS02

Signal word
Hazard statements
H261 In contact with water releases flammable gas.
Precautionary statements
P231+P232 Handle under inert gas. Protect from moisture.
P280 Wear protective gloves/protective clothing/eye protection/face protection.
P233 Keep container tightly closed.
P370+P378 In case of fire: Use for extinction: Special powder for metal fires.
P402+P404 Store in a dry place. Store in a closed container.
P501 Dispose of contents/container in accordance with local/regional/
national/international regulations.
WHMIS classification
B6 - Reactive flammable material
Classification system
HMIS ratings (scale 0-4)
(Hazardous Materials Identification System)
Health (acute effects) = 1
Flammability = 3
Physical Hazard = 2
Other hazards
Results of PBT and vPvB assessment
Not applicable.
Not applicable.


Chemical characterization: Substances
CAS# Description:
7440-24-6 strontium
Identification number(s):
EC number:


Description of first aid measures
After inhalation
Supply fresh air. If required, provide artificial respiration. Keep patient warm.
Seek immediate medical advice.
After skin contact
Immediately wash with water and soap and rinse thoroughly.
Seek immediate medical advice.
After eye contact
Rinse opened eye for several minutes under running water. Then consult a doctor.
After swallowing
Seek medical treatment.
Information for doctor
Most important symptoms and effects, both acute and delayed
No further relevant information available.
Indication of any immediate medical attention and special treatment needed
No further relevant information available.


Extinguishing media
Suitable extinguishing agents
Special powder for metal fires. Do not use water.
For safety reasons unsuitable extinguishing agents
Carbon dioxide
Special hazards arising from the substance or mixture
If this product is involved in a fire, the following can be released:
Metal oxide fume
Advice for firefighters
Protective equipment:
Wear self-contained respirator.
Wear fully protective impervious suit.


Personal precautions, protective equipment and emergency procedures
Wear protective equipment. Keep unprotected persons away.
Ensure adequate ventilation
Keep away from ignition sources
Environmental precautions:
Do not allow material to be released to the environment without proper governmental permits.
Methods and material for containment and cleaning up:
Keep away from ignition sources.
Ensure adequate ventilation.
Do not flush with water or aqueous cleansing agents
Prevention of secondary hazards:
Keep away from ignition sources.
Reference to other sections
See Section 7 for information on safe handling
See Section 8 for information on personal protection equipment.
See Section 13 for disposal information.


Precautions for safe handling
Handle under dry protective gas.
Keep container tightly sealed.
Store in cool, dry place in tightly closed containers.
Ensure good ventilation at the workplace.
Reacts violently with water
Information about protection against explosions and fires:
Protect against electrostatic charges.
Conditions for safe storage, including any incompatibilities
Requirements to be met by storerooms and receptacles:
No special requirements.
Information about storage in one common storage facility:
Store away from air.
Store away from water/moisture.
Do not store together with acids.
Store away from oxidizing agents.
Further information about storage conditions:
Store under dry inert gas.
Keep container tightly sealed.
Store in cool, dry conditions in well sealed containers.
Protect from humidity and water.
Specific end use(s)
No further relevant information available.


Additional information about design of technical systems:
Properly operating chemical fume hood designed for hazardous chemicals and having an average face velocity of at least 100 feet per minute.
Control parameters
Components with limit values that require monitoring at the workplace:
The product does not contain any relevant quantities of materials with critical values that have to be monitored at the workplace.
Additional information:
No data
Exposure controls
Personal protective equipment
General protective and hygienic measures
The usual precautionary measures for handling chemicals should be followed.
Keep away from foodstuffs, beverages and feed.
Remove all soiled and contaminated clothing immediately.
Wash hands before breaks and at the end of work.
Maintain an ergonomically appropriate working environment.
Breathing equipment:
Use suitable respirator when high concentrations are present.
Recommended filter device for short term use:
Use a respirator with type P100 (USA) or P3 (EN 143) cartridges as a backup to engineering controls. Risk assessment should be performed to determine if air-purifying respirators are appropriate. Only use equipment tested and approved under appropriate government standards.
Protection of hands:
Impervious gloves
Check protective gloves prior to each use for their proper condition.
The selection of suitable gloves not only depends on the material, but also on quality. Quality will vary from manufacturer to manufacturer.
Penetration time of glove material (in minutes)
Not determined
Eye protection:
Safety glasses
Full face protection
Body protection:
Protective work clothing


Information on basic physical and chemical properties
General Information
Form: Solid
Color: White to yellow to gold
Odor: Not determined
Odor threshold: Not determined.
pH-value: Not applicable.
Change in condition
Melting point/Melting range: 777 °C (1431 °F)
Boiling point/Boiling range: 1382 °C (2520 °F)
Sublimation temperature / start: Not determined
Flammability (solid, gaseous)
Contact with water liberates extremely flammable gases.
Ignition temperature: Not determined
Decomposition temperature: Not determined
Auto igniting: Not determined.
Danger of explosion: Not determined.
Explosion limits:
Lower: Not determined
Upper: Not determined
Vapor pressure at 20 °C (68 °F): 0 hPa
Density at 20 °C (68 °F): 2.64 g/cm³ (22.031 lbs/gal)
Relative density
Not determined.
Vapor density
Not applicable.
Evaporation rate
Not applicable.
Solubility in / Miscibility with Water: Contact with water releases flammable gases
Partition coefficient (n-octanol/water): Not determined.
dynamic: Not applicable.
kinematic: Not applicable.
Other information
No further relevant information available.


In contact with water releases flammable gases which may ignite spontaneously.
Chemical stability
Stable under recommended storage conditions.
Thermal decomposition / conditions to be avoided:
Decomposition will not occur if used and stored according to specifications.
Possibility of hazardous reactions
Reacts with strong oxidizing agents
Contact with water releases flammable gases
Conditions to avoid
No further relevant information available.
Incompatible materials:
Oxidizing agents
Hazardous decomposition products:
Metal oxide fume


Information on toxicological effects
Acute toxicity:
The Registry of Toxic Effects of Chemical Substances (RTECS) contains acute toxicity data for components in this product.
LD/LC50 values that are relevant for classification:
No data
Skin irritation or corrosion:
May cause irritation
Eye irritation or corrosion:
May cause irritation
No sensitizing effects known.
Germ cell mutagenicity:
No effects known.
No classification data on carcinogenic properties of this material is available from the EPA, IARC, NTP, OSHA or ACGIH.
Reproductive toxicity:
No effects known.
Specific target organ system toxicity - repeated exposure:
No effects known.
Specific target organ system toxicity - single exposure:
No effects known.
Aspiration hazard:
No effects known.
Subacute to chronic toxicity:
No effects known.
Additional toxicological information:
To the best of our knowledge the acute and chronic toxicity of this substance is not fully known.


Aquatic toxicity:
No further relevant information available.
Persistence and degradability
No further relevant information available.
Bioaccumulative potential
No further relevant information available.
Mobility in soil
No further relevant information available.
Additional ecological information:
General notes:
Do not allow material to be released to the environment without proper governmental permits.
Do not allow undiluted product or large quantities to reach ground water, water course or sewage system.
Avoid transfer into the environment.
Results of PBT and vPvB assessment
Not applicable.
Not applicable.
Other adverse effects
No further relevant information available.


Waste treatment methods
Consult state, local or national regulations to ensure proper disposal.
Uncleaned packagings:
Disposal must be made according to official regulations.


UN proper shipping name
Metallic substance, water-reactive, n.o.s. (strontium)
Transport hazard class(es)
4.3 Substances which, in contact with water, emit flammable gases.
4.3 (W2) Substances which, in contact with water, emit flammable gases
4.3 Substances which, in contact with water, emit flammable gases.
Packing group
Environmental hazards:
Not applicable.
Special precautions for user
Warning: Substances which, in contact with water, emit flammable gases
EMS Number: F-G,S-N
Transport in bulk according to Annex II of MARPOL73/78 and the IBC Code
Not applicable.
Transport/Additional information:
Marine Pollutant (DOT):
UN "Model Regulation":
UN3208, Metallic substance, water-reactive, n.o.s. (strontium), 4.3, II


Safety, health and environmental regulations/legislation specific for the substance or mixture
GHS label elements
The product is classified and labeled in accordance with 29 CFR 1910 (OSHA HCS)
Hazard pictograms
Signal word
Hazard statements
H261 In contact with water releases flammable gas.
Precautionary statements
P231+P232 Handle under inert gas. Protect from moisture.
P280 Wear protective gloves/protective clothing/eye protection/face protection.
P233 Keep container tightly closed.
P370+P378 In case of fire: Use for extinction: Special powder for metal fires.
P402+P404 Store in a dry place. Store in a closed container.
P501 Dispose of contents/container in accordance with local/regional/national/international regulations.
National regulations
All components of this product are listed in the U.S. Environmental Protection Agency Toxic Substances Control Act Chemical substance Inventory.
All components of this product are listed on the Canadian Domestic Substances List (DSL).
SARA Section 313 (specific toxic chemical listings)
Substance is not listed.
California Proposition 65
Prop 65 - Chemicals known to cause cancer
Substance is not listed.
Prop 65 - Developmental toxicity
Substance is not listed.
Prop 65 - Developmental toxicity, female
Substance is not listed.
Prop 65 - Developmental toxicity, male
Substance is not listed.
Information about limitation of use:
For use only by technically qualified individuals.
Other regulations, limitations and prohibitive regulations
Substance of Very High Concern (SVHC) according to the REACH Regulations (EC) No. 1907/2006.
Substance is not listed.
The conditions of restrictions according to Article 67 and Annex XVII of the Regulation (EC) No 1907/2006 (REACH) for the manufacturing, placing on the market and use must be observed.
Substance is not listed.
Annex XIV of the REACH Regulations (requiring Authorisation for use)
Substance is not listed.
Chemical safety assessment:
A Chemical Safety Assessment has not been carried out.


Safety Data Sheet according to Regulation (EC) No. 1907/2006 (REACH). The above information is believed to be correct but does not purport to be all inclusive and shall be used only as a guide. The information in this document is based on the present state of our knowledge and is applicable to the product with regard to appropriate safety precautions. It does not represent any guarantee of the properties of the product. American Elements shall not be held liable for any damage resulting from handling or from contact with the above product. See reverse side of invoice or packing slip for additional terms and conditions of sale. COPYRIGHT 1997-2016 AMERICAN ELEMENTS. LICENSED GRANTED TO MAKE UNLIMITED PAPER COPIES FOR INTERNAL USE ONLY.

Strontium Isotopes

Strontium has four stable isotopes: 84Sr (0.56%), 86Sr (9.86%), 87Sr (7.0%) and 88Sr (82.58%).

Nuclide Isotopic Mass Half-Life Mode of Decay Nuclear Spin Magnetic Moment Binding Energy (MeV) Natural Abundance
(% by atom)
73Sr 72.96597(64)# >25 ms ß+ to 73Rb; ß+ + p to 72kr 1/2-# N/A 579.71 -
74Sr 73.95631(54)# 50# ms [>1.5 µs] ß+ to 74Rb 0+ N/A 596.18 -
75Sr 74.94995(24) 88(3) ms ß+ to 75Rb; ß+ + p to 74kr (3/2-) N/A 610.78 -
76Sr 75.94177(4) 7.89(7) s ß+ to 76Rb 0+ N/A 626.31 -
77Sr 76.937945(10) 9.0(2) s ß+ to 77Rb; ß+ + p to 76kr 5/2+ N/A 638.11 -
78Sr 77.932180(8) 159(8) s ß+ to 78Rb 0+ N/A 650.85 -
79Sr 78.929708(9) 2.25(10) min ß+ to 79Rb 3/2(-) N/A 661.73 -
80Sr 79.924521(7) 106.3(15) min EC to 80Rb 0+ N/A 674.46 -
81Sr 80.923212(7) 22.3(4) min EC to 81Rb 1/2- 0.544 683.47 -
82Sr 81.918402(6) 25.36(3) d EC to 82Rb 0+ N/A 696.21 -
83Sr 82.917557(11) 32.41(3) h EC to 83Rb 7/2+ -0.898 705.22 -
84Sr 83.913425(3) Observationally Stable - 0+ N/A 717.02 0.56
85Sr 84.912933(3) 64.853(8) d EC to 85Rb 9/2+ -1.001 726.04 -
86Sr 85.9092602(12) STABLE - 0+ N/A 736.91 9.86
87Sr 86.9088771(12) STABLE - 9/2+ -1.09283 745.92 7
88Sr 87.9056121(12) STABLE - 0+ N/A 756.79 82.58
89Sr 88.9074507(12) 50.57(3) d ß- to 89Y 5/2+ -1.149 763.01 -
90Sr 89.907738(3) 28.90(3) y ß- to 90Y 0+ N/A 771.09 -
91Sr 90.910203(5) 9.63(5) h ß- to 91Y 5/2+ -0.887 776.37 -
92Sr 91.911038(4) 2.66(4) h ß- to 92Y 0+ N/A 783.52 -
93Sr 92.914026(8) 7.423(24) min ß- to 93Y 5/2+ N/A 788.8 -
94Sr 93.915361(8) 75.3(2) s ß- to 94Y 0+ N/A 795.95 -
95Sr 94.919359(8) 23.90(14) s ß- to 95Y 1/2+ N/A 800.3 -
96Sr 95.921697(29) 1.07(1) s ß- to 96Y 0+ N/A 806.52 -
97Sr 96.926153(21) 429(5) ms ß- to 97Y; ß- + n  to 96Y 1/2+ N/A 809.94 -
98Sr 97.928453(28) 0.653(2) s ß- to 98Y; ß- + n  to 97Y 0+ N/A 816.15 -
99Sr 98.93324(9) 0.269(1) s ß- to 99Y; ß- + n  to 98Y 3/2+ N/A 819.57 -
100Sr 99.93535(14) 202(3) ms ß- to 100Y; ß- + n  to 99Y 0+ N/A 825.79 -
101Sr 100.94052(13) 118(3) ms ß- to 101Y; ß- + n  to 100Y (5/2-) N/A 829.21 -
102Sr 101.94302(12) 69(6) ms ß- to 102Y; ß- + n  to 101Y 0+ N/A 837.29 -
103Sr 102.94895(54)# 50# ms [>300 ns] ß- to 103Y N/A N/A 845.37 -
104Sr 103.95233(75)# 30# ms [>300 ns] ß- to 104Y 0+ N/A 844.13 -
105Sr 104.95858(75)# 20# ms [>300 ns] Unknown N/A N/A 852.21 -