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Sulfuric acid

Athanor · official

H2O4S · 98.08 g/mol

Also called oil of vitriol, battery acid

Open in Athanor
The structure of Sulfuric acid
Drawn from its SMILES with RDKit032
CorrosiveDangerCauses severe skin burns and eye damage

Names and identifiers

IUPAC name
sulfuric acid
Synonyms
oil of vitriol, battery acid, Sulphuric acid
+ 37 more

Dihydrogen sulfate, Dipping acid, Mattling acid, Battery acid, Acide sulfurique, Electrolyte acid, Acidum sulfuricum, Sulphuricum acidum, Schwefelsaeure, tetraoxosulfuric acid, Acido solforico, Acido sulfurico, Brimstone acid, Schwefelsaeureloesungen, H2SO4, Zwavelzuuroplossingen, Dihydrogen sulphate, DTXSID5029683, Anhydrous sulfuric acid, Nordhausen acid, Matting acid, O40UQP6WCF, NSC-38965, EPA Pesticide Chemical Code 078001, NSC-248648, INS NO.513, CHEBI:26836, INS-513, DTXCID709683, E-513, NSC38965, NSC248648, (S(OH)2O2), [S(OH)2O2], Sulfuric acid (aqueous), sulfur acid, Colds Flu

Molecular formula
H2O4S
Empirical formula
H2O4S
Molecular weight
98.08 g/mol
Exact mass
97.96738
CAS number
7664-93-9
PubChem CID
1118
Canonical SMILES
OS(=O)(=O)O
Isomeric SMILES
OS(=O)(=O)O
InChI
InChI=1S/H2O4S/c1-5(2,3)4/h(H2,1,2,3,4)
InChIKey
QAOWNCQODCNURD-UHFFFAOYSA-N
Molfile

Names, InChI and the identifiers from PubChem, retrieved 2026-10-14.

Physical properties

TemperaturePressureDensity
Appearance
Dense, oily liquid; colorless to dark brown depending on purity[6]
8 values

From Hazardous Substances Data Bank (HSDB), the most authoritative source here.

ValueAs writtenSource
–Sulfuric acid is a colorless oily liquid. It is soluble in water with release of heat. It is corrosive to metals and tissue. It will char wood and most other organic matter on contact, but is unlikely to cause a fire. Density 15 lb / gal. Long term exposure to low concentrations or short term exposure to high concentrations can result in adverse health effects from inhalation. It is used to make fertilizers and other chemicals, in petroleum refining, in iron and steel production, and for many other uses. Rate of onset: Immediate Persistence: Hours, days Odor threshold: Source/use/other h[1] CAMEO Chemicals
–Sulfuric acid, spent appears as a black oily liquid. Corrosive to metals and tissue. Density 15 lb /gal.[1] CAMEO Chemicals
–Gas Vapor; Liquid; Liquid; Liquid; Other Solid; CBI; Dry Powder; Gas Vapor[2] EPA Chemical Data Reporting (CDR)
–ODOURLESS COLOURLESS OILY HYGROSCOPIC LIQUID.[3] ILO-WHO International Chemical Safety Cards (ICSCs)
–Colorless to dark-brown, oily, odorless liquid.[4] Occupational Safety and Health Administration (OSHA)
–Colorless to dark-brown, oily, odorless liquid. [Note: Pure compound is a solid below 51 °F. Often used in an aqueous solution.][5] The National Institute for Occupational Safety and Health (NIOSH)
–shownDense, oily liquid; colorless to dark brown depending on purity[6] Hazardous Substances Data Bank (HSDB)cites Larranaga, M.D., Lewis, R.J. Sr., Lewis, R.A.; Hawley's Condensed Chemical Dictionary 16th Edition. John Wiley & Sons, Inc. Hoboken, NJ 2016., p. 1290
–Colorless to dark brown, oily liquid [Note: Pure compound is a solid below 51 degrees F. Often used in an aqueous solution][6] Hazardous Substances Data Bank (HSDB)cites NIOSH. NIOSH Pocket Guide to Chemical Hazards. Department of Health & Human Services, Centers for Disease Control & Prevention. National Institute for Occupational Safety & Health. DHHS (NIOSH) Publication No. 2010-168 (2010). Available from: https://www.cdc.gov/niosh/npg
Melting point
10.31 °C[7]
6 values

5 of 5 sources agree on it (most common value).

ValueAs writtenSource
10.4 °C50.65 °F (EPA, 1998)[1] CAMEO Chemicalscites U.S. Environmental Protection Agency. 1998. Extremely Hazardous Substances (EHS) Chemical Profiles and Emergency First Aid Guides. Washington, D.C.: U.S. Government Printing Office.
11 °C51 °F (NIOSH, 2024)[1] CAMEO Chemicals
10 °C10 °C[3] ILO-WHO International Chemical Safety Cards (ICSCs)
11 °C51 °F[4] Occupational Safety and Health Administration (OSHA)
10.3 °Cshown10.31 °C[7] PAC Chemical Database, U.S. Department of Energy
11 °C51 °F[5] The National Institute for Occupational Safety and Health (NIOSH)
Boiling point
290 °C (554 °F) at 760 mmHg (EPA, 1998)[1]
5 values

3 of 4 sources agree on it (most common value).

ValueAs writtenSource
290 °Cshown554 °F at 760 mmHg (EPA, 1998)[1] CAMEO Chemicalscites U.S. Environmental Protection Agency. 1998. Extremely Hazardous Substances (EHS) Chemical Profiles and Emergency First Aid Guides. Washington, D.C.: U.S. Government Printing Office.
100 °C212 °F at 760 mmHg (USCG, 1999)[1] CAMEO Chemicalscites U.S. Coast Guard. 1999. Chemical Hazard Response Information System (CHRIS) - Hazardous Chemical Data. Commandant Instruction 16465.12C. Washington, D.C.: U.S. Government Printing Office.
290 °C554 °F[4] Occupational Safety and Health Administration (OSHA)
337 °C337 °C @760 [mm Hg][7] PAC Chemical Database, U.S. Department of Energy
290 °C554 °F[5] The National Institute for Occupational Safety and Health (NIOSH)
Density
1.8302 @25 °C[7]
7 values

5 of 6 sources agree on it (most common value).

ValueAs writtenSource
–1.841 (EPA, 1998) - Denser than water[1] CAMEO Chemicalscites U.S. Environmental Protection Agency. 1998. Extremely Hazardous Substances (EHS) Chemical Profiles and Emergency First Aid Guides. Washington, D.C.: U.S. Government Printing Office.
–1.39 at 68 °F (USCG, 1999) - Denser than water[1] CAMEO Chemicalscites U.S. Coast Guard. 1999. Chemical Hazard Response Information System (CHRIS) - Hazardous Chemical Data. Commandant Instruction 16465.12C. Washington, D.C.: U.S. Government Printing Office.
–density: 1.675-1.710 at 15 °C /Commercial acid/[6] Hazardous Substances Data Bank (HSDB)cites MacBean C, ed; e-Pesticide Manual. 15th ed., ver. 5.1, Alton, UK; British Crop Protection Council. Sulfurid Acid (7664-93-9) (2008-2010)
–Relative density (water = 1): 1.8 (20 °C)[3] ILO-WHO International Chemical Safety Cards (ICSCs)
–1.84 (96-98% acid)[4] Occupational Safety and Health Administration (OSHA)
–shown1.8302 @25 °C[7] PAC Chemical Database, U.S. Department of Energy
–1.84 (96-98% acid)[5] The National Institute for Occupational Safety and Health (NIOSH)
Solubility in water
Solubility in water at 20 °C: miscible[3]
4 values

From ILO-WHO International Chemical Safety Cards (ICSCs), the most authoritative source here.

ValueAs writtenSource
–Miscible (NIOSH, 2024)[1] CAMEO Chemicals
–Miscible (NIOSH, 2024)[1] CAMEO Chemicals
–shownSolubility in water at 20 °C: miscible[3] ILO-WHO International Chemical Safety Cards (ICSCs)
–Miscible[5] The National Institute for Occupational Safety and Health (NIOSH)
pKa
pKa = 1.92 at 25 °C[6]
Vapor pressure
Vapor pressure: 1 mmHg at 145.8 °C[6]
3 values

2 of 2 sources agree on it (most common value).

ValueAs writtenSource
1 mmHg1 mmHg at 294.8 °F (EPA, 1998)[1] CAMEO Chemicalscites U.S. Environmental Protection Agency. 1998. Extremely Hazardous Substances (EHS) Chemical Profiles and Emergency First Aid Guides. Washington, D.C.: U.S. Government Printing Office.
1 mmHgshownVapor pressure: 1 mm Hg at 145.8 °C[6] Hazardous Substances Data Bank (HSDB)cites Lewis, R.J. Sr. (ed) Sax's Dangerous Properties of Industrial Materials. 12th Edition. Wiley-Interscience, Wiley & Sons, Inc. Hoboken, NJ. 2012., p. 4107
0.0000593 mmHg5.93X10-5 mm Hg at 25 °C /from experimentally-derived coefficients/[6] Hazardous Substances Data Bank (HSDB)cites Daubert TE, Danner RP; Physical and Thermodynamic Properties of Pure Chemicals: Data Compilation. Design Institute for Physical Property Data, American Institute of Chemical Engineers. New York, NY: Hemisphere Pub Corp (2000)

4 more values were reported but failed the checks (unreadable or out of range), so they are not shown.

Autoignition temperature
Reported, but no value passed the checks.
The 2 values and why
  • Not flammable (USCG, 1999) (could not be read; source [1])
  • Not flammable (USCG, 1999) (could not be read; source [1])
Viscosity
21 mPa.s at 25 °C[6]

Each value as its source reports it, with the source's number after it (listed under References). Where several sources report a property, the row shows the value most of them agree on, the rule the app uses; open the values to see every one.

Calculated

Heavy atoms
5
Rings
0
Aromatic rings
0
Fraction sp³ carbons (Fsp3)
0
H-bond donors
2
H-bond acceptors
2 computed here · PubChem 4
Rotatable bonds
0
TPSA (Ų)
74.6 computed here · PubChem 83
Formal charge
0
XLogP3
-1.4 PubChem
Complexity
81 PubChem
Stereocenters
None
Double-bond geometry
None specified
Point group
C2 of one 3D conformer with its hydrogens, by Athanor’s engine (as in the app)

Elemental analysis

  • H2.06%
  • O65.25%
  • S32.70%

Isotope pattern

100%97.96798.9685.3%99.965

Each peak is a nominal mass with its abundance-weighted exact mass, as a percentage of the tallest, from IUPAC natural isotope abundances.

Computed from the structure with RDKit 2026.09 when this page was built, beside PubChem's own computed values from its record; where the two differ, both are shown.

Predicted

log P
-0.65 Crippen (Wildman and Crippen 1999)
log S (water solubility)
-0.04 ESOL (Delaney 2004), log mol/L
Synthetic accessibility
2.02 SA score, 1 easy to 10 hard (Ertl and Schuffenhauer 2009)

Drug-likeness: Lipinski’s rule of five

  • Molecular weight ≤ 500: 98.08
  • log P ≤ 5 (Crippen): -0.65
  • H-bond donors ≤ 5: 2
  • H-bond acceptors ≤ 10: 2

Passes all four rules.

Predictions, not measurements; each names its method. A measured log P, where a source reports one, is under Physical properties.

Safety

Danger

Harmonized EU classification (CLP Annex VI). Source [8].

  • Corrosive
032
NFPA 704[6]
  • H314Causes severe skin burns and eye damage

Precautionary statements: P260, P264, P280, P301+P330+P331, P302+P361+P354, P304+P340, P305+P354+P338, P316, P321, P363, P405, P501

View all classifications (4)
  • [8] Regulation (EC) No 1272/2008 of the European Parliament and of the Council · DangerH314
  • [9] European Chemicals Agency (ECHA)This chemical does not meet GHS hazard criteria for < 0.1% (1 of 8811) of reports.
  • [9] European Chemicals Agency (ECHA) · 8,811 reports · DangerNo hazard statements
  • [6] Hazardous Substances Data Bank (HSDB) · DangerH290, H314, H318

Exposure limits

  • PEL-TWA (8-Hour Time Weighted Average): 1 mg/m³[4]
  • PEL: TWA 1 mg/m3[5]
  • TLV: 0.2 mg/m[3]
  • TLV-TWA (Time Weighted Average): 0.2 mg/m³ (thoracic particulate matter) [2000][4]
  • IDLH: 15 mg/m3 (NIOSH, 2024)[1]
  • IDLH: 15 mg/m3 [From npg: Sulfuric acid] (NIOSH, 2024)[1]

First aid

  • Caution: Sulfuric acid is extremely corrosive. Caution is advised. Signs and Symptoms of Acute Sulfuric Acid Exposure: Signs and symptoms of acute ingestion of sulfuric acid may be severe and include salivation, intense thirst, difficulty in swallowing, pain, and shock. Oral, esophageal, and stomach burns are common. Vomitus generally has a coffee-ground appearance. The potential for circulatory collapse is high following ingestion of sulfuric acid.[1]
  • Excerpt from NIOSH Pocket Guide for Sulfuric acid: Eye: Irrigate immediately - If this chemical contacts the eyes, immediately wash (irrigate) the eyes with large amounts of water, occasionally lifting the lower and upper lids. Get medical attention immediately. Skin: Water flush immediately - If this chemical contacts the skin, immediately flush the contaminated skin with water. If this chemical penetrates the clothing, immediately remove the clothing and flush the skin with water.[1]
  • General First Aid: · Call 911 or emergency medical service. · Ensure that medical personnel are aware of the material(s) involved, take precautions to protect themselves and avoid contamination. · Move victim to fresh air if it can be done safely. · Administer oxygen if breathing is difficult. · If victim is not breathing: -- DO NOT perform mouth-to-mouth resuscitation; the victim may have ingested or inhaled the substance. -- If equipped and pulse detected, wash face and mouth, then give artificial respiration using a proper respiratory medical device (bag-valve mask, pocket mask equipped…[10]
  • General First Aid: · Call 911 or emergency medical service. · Ensure that medical personnel are aware of the material(s) involved, take precautions to protect themselves and avoid contamination. · Move victim to fresh air if it can be done safely. · Administer oxygen if breathing is difficult. · If victim is not breathing: -- DO NOT perform mouth-to-mouth resuscitation; the victim may have ingested or inhaled the substance. -- If equipped and pulse detected, wash face and mouth, then give artificial respiration using a proper respiratory medical device (bag-valve mask, pocket mask equipped…[10]

Storage

  • Dry. Separated from food and feedstuffs and incompatible materials. See Chemical Dangers. Store only in original packaging.[3]
  • Keep container tightly closed in a dry and well-ventilated place. Containers which are opened must be carefully resealed and kept upright to prevent leakage.[6]
  • Smoking, open lights, flames, and spark-producing tools shall not be permitted near sulfuric acid carboys, drums, tank cars, or metal storage tanks because of the possible production of explosive mixtures of hydrogen during storage.[6]
  • Store in cool, dry, well-ventilated location. Separate from combustibles, and other reactive materials. Separate from carbides, chlorates, fulminates, nitrates, picrates, and powdered metals.[6]

Incompatibilities

  • Incompatible materials: Bases, halides, organic materials, carbides, fulminates, nitrates, picrates, cyanides, chlorates, alkali halides, zinc salts, permanganates, e.g. Potassium permanganate, hydrogen peroxide, azides, perchlorates, nitromethane, phosphorous; Reacts violently with: Cyclopentadiene, cyclopentanone oxime, nitroaryl amines, hexalithium disilicide, phosphorous(iii) oxide, powdered metals.[6]
  • P-Chloronitrobenzene, sulfur trioxide and sulfuric acid: The reaction mixture from sulfonation of the nitro-compound in 20% oleum, containing 35% wt of 2-chloro-5-nitrobenzene-sulfonic acid, shows two exothermic stages at 100 °C, respectively, the latter being violently rapid. The adiabatic reaction mixture, initially at 89 °C, attained 285 °C with boiling after 17 hr. At 180 °C the induction period was about 20 min. Sulfonation of p-chloronitrobenzene with 65% oleum at 46 °C led to a runaway decomposition reaction in a 2000 l vessel. The original process using 20% oleum was less sensitive to[6]
  • Addition of sulfuric acid to the cyano-alcohol caused a vigorous reaction which pressure-ruptured. This seems likely to have been due to insufficient cooling to prevent dehydration of the alcohol to methylacrylonitrile and lack of inhibitors to prevent exothermic polymerization of the nitrile.[6]
  • Cyclopentanone oxime and sulfuric acid: Heating the oxime with 85% sulfuric acid to effect the Beckmann rearrangement caused eruption of the stirred flask contents. Benzenesulfonyl chloride in alkali was a less vigorous reagent.[6]

Always read the supplier’s safety data sheet before working with it.

Spectra

Experimental spectra held by these sources; each link opens the source's own record.

Literature

Reading PubChem, OpenAlex and GSRS…

Bioactivity

Reading ChEMBL…

References

  1. [1]CAMEO Chemicals · Public domain (NOAA) · via PubChem · retrieved 2026-10-14
  2. [2]EPA Chemical Data Reporting (CDR) · Public domain (US EPA) · via PubChem · retrieved 2026-10-14
  3. [3]ILO-WHO International Chemical Safety Cards (ICSCs) · CC BY 4.0 · via PubChem · retrieved 2026-10-14
  4. [4]Occupational Safety and Health Administration (OSHA) · Public domain (US DOL) · via PubChem · retrieved 2026-10-14
  5. [5]The National Institute for Occupational Safety and Health (NIOSH) · Public domain (US CDC) · via PubChem · retrieved 2026-10-14
  6. [6]Hazardous Substances Data Bank (HSDB) · Public domain (US NLM) · via PubChem · retrieved 2026-10-14
  7. [7]PAC Chemical Database, U.S. Department of Energy · Public domain (US DOE) · via PubChem · retrieved 2026-10-14
  8. [8]Regulation (EC) No 1272/2008 of the European Parliament and of the Council · EU reuse policy, CC BY 4.0 · via PubChem · retrieved 2026-10-14
  9. [9]European Chemicals Agency (ECHA) · ECHA legal notice: reuse with acknowledgement · via PubChem · retrieved 2026-10-14
  10. [10]Emergency Response Guidebook (ERG) · Public domain (US DOT) · via PubChem · retrieved 2026-10-14
  11. [11]SpectraBase · Linked only · via PubChem · retrieved 2026-10-14
  12. [12]Human Metabolome Database (HMDB) · Linked only · via PubChem · retrieved 2026-10-14
  13. [13]MassBank of North America (MoNA) · CC BY 4.0 · via PubChem · retrieved 2026-10-14
  14. [14]NIST Mass Spectrometry Data Center · Linked only · via PubChem · retrieved 2026-10-14
  15. ·Calculated values: computed by Athanor with RDKit 2026.09 from the structure.
  16. ·Literature on PubChem

Data last updated 2026-10-14.