Record Information
Version2.0
Creation Date2014-10-02 22:12:24 UTC
Update Date2014-12-24 20:27:00 UTC
Accession NumberT3D4968
Identification
Common NameHydrochloric acid
ClassSmall Molecule
DescriptionHCl refers to both hydrogen chloride gas and aqueous hydrochloric acid. Hydrogen chloride gas is a colorless gas formed from the reaction of hydrogen with chlorine. It forms white fumes of hydrochloric acid upon contact with atmospheric humidity. Hydrochloric acid is a highly corrosive, strong mineral acid with many industrial uses. Hydrochloric acid is found naturally in gastric acid. Hydrogen chloride gas and hydrochloric acid are important in technology and industry. For example, hydrochloric acid is used in the chemical industry as a chemical reagent in the large-scale production of vinyl chloride for PVC plastic, and MDI/TDI for polyurethane. It has numerous smaller-scale applications, including household cleaning, production of gelatin and other food additives, descaling, and leather processing. Hydrogen chloride is less widely used, although even in the absence of water, hydrogen chloride can still act as an acid. For example, hydrogen chloride can dissolve in certain other solvents such as methanol, protonate molecules or ions, and serve as an acid-catalyst for chemical reactions where anhydrous (water-free) conditions are desired. Hydrogen chloride is corrosive, particularly in the presence of moisture. Likewise hydrochloric acid is also extremely corrosive. Most hydrochloric acid is sold or is available as a 38% aqueous solution.
Compound Type
  • Industrial/Workplace Toxin
  • Metabolite
  • Natural Compound
Chemical Structure
Thumb
Synonyms
Synonym
HCl
Hydrochlorate
Hydrochloride
Hydrogen chloride
[HCl]
Chemical FormulaClH
Average Molecular Mass36.461 g/mol
Monoisotopic Mass35.977 g/mol
CAS Registry Number7647-01-0
IUPAC Namehydrogen chloride
Traditional Namehydrogen chloride
SMILESCl
InChI IdentifierInChI=1S/ClH/h1H
InChI KeyInChIKey=VEXZGXHMUGYJMC-UHFFFAOYSA-N
Chemical Taxonomy
Description belongs to the class of inorganic compounds known as halogen hydrides. These are inorganic compounds in which the heaviest atom bonded to a hydrogen atom is a halogen.
KingdomInorganic compounds
Super ClassHomogeneous non-metal compounds
ClassHalogen organides
Sub ClassHalogen hydrides
Direct ParentHalogen hydrides
Alternative Parents
Substituents
  • Halogen hydride
  • Inorganic hydride
Molecular FrameworkNot Available
External Descriptors
Biological Properties
StatusDetected and Not Quantified
OriginExogenous
Cellular Locations
  • Cell junction
  • Cell surface
  • Endoplasmic reticulum
  • Microtubule
  • Mitochondrion
  • Nerve Fiber
  • Nuclear Membrane
  • Plasma Membrane
Biofluid LocationsNot Available
Tissue LocationsNot Available
Pathways
NameSMPDB LinkKEGG Link
TetracyclinesNot AvailableNot Available
Pancreatic secretionNot Availablemap04972
Gastric acid secretionNot Availablemap04971
Insulin secretionNot Availablemap04911
Salivary secretionNot Availablemap04970
QuinolinesNot AvailableNot Available
PhenothiazinesNot AvailableNot Available
Cell cycleNot Availablemap04110
ApoptosisNot Availablemap04210
ApplicationsNot Available
Biological RolesNot Available
Chemical RolesNot Available
Physical Properties
StateGas or Liquid
AppearanceColorless gas (hydrogen chloride) or liquid (hydrochloric acid)
Experimental Properties
PropertyValue
Melting PointNot Available
Boiling Point51°C (hydrochloric acid)
SolubilityNot Available
LogPNot Available
Predicted Properties
PropertyValueSource
logP0.61ChemAxon
pKa (Strongest Acidic)-7ChemAxon
Physiological Charge-1ChemAxon
Hydrogen Acceptor Count0ChemAxon
Hydrogen Donor Count0ChemAxon
Polar Surface Area0 ŲChemAxon
Rotatable Bond Count0ChemAxon
Refractivity6.42 m³·mol⁻¹ChemAxon
Polarizability2.65 ųChemAxon
Number of Rings0ChemAxon
Bioavailability1ChemAxon
Rule of FiveYesChemAxon
Ghose FilterYesChemAxon
Veber's RuleYesChemAxon
MDDR-like RuleYesChemAxon
Spectra
Spectra
Spectrum TypeDescriptionSplash KeyDeposition DateView
Predicted GC-MSPredicted GC-MS Spectrum - GC-MS (Non-derivatized) - 70eV, Positivesplash10-000i-9000000000-9c67ad6c6de9138449dd2017-09-01View Spectrum
Predicted GC-MSPredicted GC-MS Spectrum - GC-MS (Non-derivatized) - 70eV, PositiveNot Available2021-10-12View Spectrum
LC-MS/MSLC-MS/MS Spectrum - Linear Ion Trap , negativesplash10-0a4i-0000009000-8651ed5a563be0ad942f2017-09-14View Spectrum
LC-MS/MSLC-MS/MS Spectrum - Linear Ion Trap , negativesplash10-0a4i-0000009000-6193af2f15253417208c2017-09-14View Spectrum
LC-MS/MSLC-MS/MS Spectrum - Linear Ion Trap , positivesplash10-014i-0000900000-5818c00db6f91eb3e74d2017-09-14View Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 10V, Positivesplash10-000i-9000000000-942cba57b20ee16a420d2016-08-03View Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 20V, Positivesplash10-000i-9000000000-942cba57b20ee16a420d2016-08-03View Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 40V, Positivesplash10-000i-9000000000-942cba57b20ee16a420d2016-08-03View Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 10V, Negativesplash10-001i-9000000000-5849201eeb63a76419cf2016-08-03View Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 20V, Negativesplash10-001i-9000000000-5849201eeb63a76419cf2016-08-03View Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 40V, Negativesplash10-001i-9000000000-5849201eeb63a76419cf2016-08-03View Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 10V, Negativesplash10-001i-9000000000-c2fa753da65a4bac80a12021-09-22View Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 20V, Negativesplash10-001i-9000000000-c2fa753da65a4bac80a12021-09-22View Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 40V, Negativesplash10-001i-9000000000-c2fa753da65a4bac80a12021-09-22View Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 10V, Positivesplash10-000i-9000000000-a69f8335a8796781b4b02021-09-23View Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 20V, Positivesplash10-000i-9000000000-a69f8335a8796781b4b02021-09-23View Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 40V, Positivesplash10-000i-9000000000-a69f8335a8796781b4b02021-09-23View Spectrum
Toxicity Profile
Route of ExposureInhalation; Ingestion; Dermal; Eyes
Mechanism of ToxicityBoth hydrogen chloride gas and hydrochloric acid are highly corrosive. Many strong acids cause tissue burns through the denaturation of proteins and partial hydrolysis of proteins. Most proteins denature at pH values of less than 3-4. The large-scale denaturation of proteins, de-esterification of lipids and subsequent desiccation of tissues leads to chemical burns. Symptoms include itching, bleaching or darkening of skin or tissues, blistering and burning sensations.
MetabolismNot Available
Toxicity ValuesLD50 [oral, rat]; 700 mg/kg; LD50 [rat]; 3124 ppm (1 hour)
Lethal Dose2857 ug/kg (Oral), 1300 ppm/30 minutes (inhalation)
Carcinogenicity (IARC Classification)3, not classifiable as to its carcinogenicity to humans. (1)
Uses/SourcesHydrochloric acid is found naturally in gastric acid. Most hydrogen chloride gas is used in the production of hydrochloric acid. HCl gas is also an important reagent in other industrial chemical transformations. For example, the hydrochlorination of rubber and the production of vinyl and alkyl chlorides. In the semiconductor industry, it is used to both etch semiconductor crystals and to purify silicon via trichlorosilane (SiHCl3). It may also be used to treat cotton to delint it, and to separate it from wool. In the chlor-alkali industry, brine (mixture of sodium chloride and water) solution is electrolyzed producing chlorine (Cl2), sodium hydroxide, and hydrogen (H2). The pure chlorine gas can be combined with hydrogen to produce hydrogen chloride in the presence of UV light.
Minimum Risk LevelOccupational exposure limits for hydrogen chloride (gas) have been set at 5 ppm
Health EffectsHydrogen chloride forms corrosive hydrochloric acid on contact with water found in body tissue. Inhalation of the fumes can cause coughing, choking, inflammation of the nose, throat, and upper respiratory tract, and in severe cases, pulmonary edema, circulatory system failure, and death. Skin contact can cause redness, pain, and severe skin burns. Both hydrogen chloride gas and hydrochloric acid may cause severe burns to the eye and permanent eye damage. Severe and rapid corrosive burns of the mouth, gullet and gastrointestinal tract will result if hydrochloric acid is swallowed. Symptoms include burning, choking, nausea, vomiting and severe pain. Concentrated hydrochloric acid (fuming hydrochloric acid) forms acidic mists. Both the mist and the solution have a corrosive effect on human tissue, with the potential to damage respiratory organs, eyes, skin, and intestines irreversibly. Upon mixing hydrochloric acid with common oxidizing chemicals, such as sodium hypochlorite (bleach, NaClO) or potassium permanganate (KMnO4), the toxic gas chlorine is produced. Chronic exposure to hydrogen chloride can lead to liver damage, bleeding of nose and gums, nasal and oral mucosal ulceration, conjunctivitis, yellowing of teeth and erosion of tooth enamel as well as dermatitis.
SymptomsInhalation of HCl fumes can cause coughing, choking, inflammation of the nose, throat, and upper respiratory tract, and in severe cases, pulmonary edema, circulatory system failure, and death. Skin contact can cause redness, pain, and severe skin burns. Hydrogen chloride may cause severe burns to the eye and permanent eye damage. Severe and rapid corrosive burns of the mouth, gullet and gastrointestinal tract will result if hydrochloric acid is swallowed. Symptoms include burning, choking, nausea, vomiting and severe pain.
TreatmentThe mainstay of treatment of any acid burn is copious irrigation with large amounts of tap water. To be most effective, treatment should be started immediately after exposure, preferably before arrival in the emergency department. Remove any contaminated clothing. Do not attempt to neutralize the burn with weak reciprocal chemicals (i.e. alkali for acid burns), because the heat generated from the chemical reaction may cause severe thermal injury.
Normal Concentrations
Not Available
Abnormal Concentrations
Not Available
DrugBank IDNot Available
HMDB IDHMDB02306
PubChem Compound ID313
ChEMBL IDCHEMBL1231821
ChemSpider ID307
KEGG IDC01327
UniProt IDNot Available
OMIM ID
ChEBI ID17883
BioCyc IDNot Available
CTD IDNot Available
Stitch IDNot Available
PDB IDNot Available
ACToR IDNot Available
Wikipedia LinkHydrochloric acid
References
Synthesis ReferenceNot Available
MSDSNot Available
General References
  1. International Agency for Research on Cancer (2014). IARC Monographs on the Evaluation of Carcinogenic Risks to Humans. [Link]
Gene Regulation
Up-Regulated GenesNot Available
Down-Regulated GenesNot Available