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Silicates, borates and other salts

Isocyanic acid

Also known as Hydrogen isocyanate, HNCO, isozyansaeure

CAS 75-13-8Formula CHNOMolar mass 43.03 g/molEC 616-189-3
GHS signal word: Danger. Pictograms: Corrosive, Harmful or irritant, Serious health hazard 1 supplier listed
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Isocyanic acid chemical structure, CHNO, CAS 75-13-8
2D chemical structure

Key facts

What buyers check first

All properties
CAS number
75-13-8
Formula
CHNO
Molar mass
43.03 g/mol
EC number
616-189-3
HS code
285390
Category
Silicates, borates and other salts

What is Isocyanic acid?

Plain description, key identifiers and synonyms

Isocyanic acid is a colourless, volatile, poisonous inorganic compound with the formula HNCO, the simplest stable chemical compound that contains carbon, hydrogen, nitrogen, and oxygen, the four most commonly-found elements in organic chemistry and biology. It is a hydracid and a one-carbon compound. It is a conjugate acid of a cyanate. It is a tautomer of a cyanic acid.

Isocyanic acid is a chemical compound of structural formula HNCO.

Identifiers

Registry numbers, names and line notations, tap to copy

IUPAC name
isocyanic acid
CAS number
75-13-8 CAS number cross-checked
EC number
616-189-3
Molecular formula
CHNO
UNII
QKG6U31925
InChIKey
OWIKHYCFFJSOEH-UHFFFAOYSA-N
InChI
InChI=1S/CHNO/c2-1-3/h2H
SMILES (canonical and isomeric)
C(=N)=O

Synonyms

  • Hydrogen isocyanate
  • HNCO
  • isozyansaeure
  • oxidoazanediidocarbon
  • HN=C=O
  • Isocyanic acid (hnco)
  • [C(NH)O]
  • (C(NH)O)
  • carboximidoyloxidane
  • isocyansaeure
  • CHNO
  • imino-ketone
  • H N C O

Physical and chemical properties

Measured values and descriptors computed from the structure

Physical and chemical properties

Measured values, check the supplier specification for your grade

Vapour pressure
996 [mm Hg] @25 °Cexp.

Values vary by grade. Ask suppliers for the COA or TDS of the batch you buy.

Computed descriptors

Calculated from the structure, useful for screening and formulation

Molecular weight
43.03 g/molcalc.
Exact mass
43.0058 Dacalc.
LogP (octanol/water)
-0.1calc.
Topological polar surface area
40.92 Ųcalc.
Hydrogen bond donors
1calc.
Hydrogen bond acceptors
2calc.
Rotatable bonds
0calc.
Heavy atoms
3calc.
Rings
0calc.
Aromatic rings
0calc.
Fraction sp3 carbons
0calc.
Formal charge
0calc.
Stereocentres
0calc.

Calculated for screening. Confirm critical figures with the supplier.

Safety and hazards

GHS classification summary, not a safety data sheet

GHS signal word
Danger
GHS05: Corrosive
Corrosive
GHS07: Harmful or irritant
Harmful or irritant
GHS08: Serious health hazard
Serious health hazard

Hazard statements

  • H302Harmful if swallowed.
  • H312Harmful in contact with skin.
  • H314Causes severe skin burns and eye damage.
  • H332Harmful if inhaled.
  • H334May cause allergy or asthma symptoms or breathing difficulties if inhaled.
  • H335May cause respiratory irritation.
Precautionary statements (26)
  • P233Keep container tightly closed.
  • P260Do not breathe dust, fume, gas, mist, vapours or spray.
  • P261Avoid breathing dust, fume, gas, mist, vapours or spray.
  • P264Wash skin thoroughly after handling.
  • P270Do not eat, drink or smoke when using this product.
  • P271Use only outdoors or in a well-ventilated area.
  • P280Wear protective gloves, protective clothing, eye protection and face protection.
  • P284In case of inadequate ventilation wear respiratory protection.
  • P301 + P317If swallowed: Get medical help.
  • P301 + P330 + P331If swallowed: Rinse mouth. Do not induce vomiting.
  • P302 + P352If on skin: Wash with plenty of water.
  • P302 + P361 + P354If on skin: Take off immediately all contaminated clothing. Immediately rinse with water for several minutes.
  • P304 + P340If inhaled: Remove person to fresh air and keep comfortable for breathing.
  • P305 + P354 + P338If in eyes: Immediately rinse with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing.
  • P316Get emergency medical help immediately.
  • P317Get medical help.
  • P319Get medical help if you feel unwell.
  • P321Specific treatment (see supplemental first aid instructions on the label).
  • P330Rinse mouth.
  • P342 + P316If experiencing respiratory symptoms: Get emergency medical help immediately.
  • P362 + P364Take off contaminated clothing. And wash it before reuse.
  • P363Wash contaminated clothing before reuse.
  • P403Store in a well-ventilated place.
  • P403 + P233Store in a well-ventilated place. Keep container tightly closed.
  • P405Store locked up.
  • P501Dispose of contents and container in accordance with local regulations.

GHS classification summary, not a safety data sheet (SDS). Classifications can differ by supplier, grade and concentration. Always check the supplier's SDS.

Full safety data and first aid

Isocyanic acid suppliers

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Where suppliers are based

1 supplier in 0 countries

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Isocyanic acid price

Indicative price range per kg from live supplier offers

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Uses and applications

What the substance is used for, by industry and function

Roles

  • animal metabolite
  • eukaryotic metabolite
  • human metabolite
  • mammalian metabolite
  • metabolite

Regulatory status

Inventories, regulations and trade controls that list this substance

No regulatory list memberships are recorded for this substance yet. Always check the rules of the importing and exporting country before trade.

HS code and trade data

Customs classification and reported world trade statistics

Global trade

World import and export statistics for the HS code Isocyanic acid is traded under.

HS 2853.90Indicative HS code

Phosphides, whether or not chemically defined, excluding ferrophosphorus, other, other

World exports in 2024
$2.45B
−33.6% vs 2023, imports $816M
2019 to 2024
Top exporters
  1. China68.4%
  2. Israel8.1%
  3. United States4.9%
Top importers
  1. United States19.3%
  2. Japan17.9%
  3. China13.4%
Reported customs values in USD, not prices.Full trade data

The HS code shown for Isocyanic acid is indicative (it is known at chapter level only). Confirm the classification with your customs broker before shipping.

Frequently asked questions

Quick answers about Isocyanic acid, based on the data on this page

What is Isocyanic acid?

Isocyanic acid is a colourless, volatile, poisonous inorganic compound with the formula HNCO, the simplest stable chemical compound that contains carbon, hydrogen, nitrogen, and oxygen, the four most commonly-found elements in organic chemistry and biology. It is a hydracid and a one-carbon compound.

What is the CAS number of Isocyanic acid?

The CAS registry number of Isocyanic acid is 75-13-8.

What is the molecular formula and weight of Isocyanic acid?

The molecular formula of Isocyanic acid is CHNO and its molar mass is 43.03 g/mol.

What is Isocyanic acid used for?

Known uses and roles of Isocyanic acid include animal metabolite, eukaryotic metabolite, human metabolite, mammalian metabolite and metabolite.

Is Isocyanic acid hazardous?

Isocyanic acid carries the GHS signal word "Danger". Main hazards: harmful if swallowed, harmful in contact with skin, causes severe skin burns and eye damage. This summary is not an SDS, always read the supplier safety data sheet.

What is the HS code of Isocyanic acid?

Isocyanic acid is usually classified under HS code 285390 (Phosphides, whether or not chemically defined, excluding ferrophosphorus, other…). This is indicative, confirm it with your customs broker before shipping.

Where can I buy Isocyanic acid?

CompoundList lists 1 supplier of Isocyanic acid. Send one free request to get and compare quotes. Your contact details stay private until you accept a quote.

What is the price of Isocyanic acid?

Suppliers quote Isocyanic acid on request because prices depend on grade, purity, quantity and destination. A free request on CompoundList gets you several quotes to compare.

Guides for buyers

Practical guides that help when you source, ship or handle Isocyanic acid

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Data last updated 7 Oct 2026. Details may have changed, please confirm them with the supplier. Report an error on this page
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