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Impurities and reference standards

Isonicotinic acid

Also known as 4-Pyridinecarboxylic acid, Pyridine-4-carboxylic acid, 4-Carboxypyridine

CAS 55-22-1Formula C6H5NO2Molar mass 123.11 g/molEC 200-228-2
GHS signal word: Warning. Pictograms: Harmful or irritant 89 suppliers listed
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Isonicotinic acid chemical structure, C6H5NO2, CAS 55-22-1
2D chemical structure

Key facts

What buyers check first

All properties
CAS number
55-22-1
Formula
C6H5NO2
Molar mass
123.11 g/mol
EC number
200-228-2
HS code
293980
Category
Impurities and reference standards

What is Isonicotinic acid?

Plain description, key identifiers and synonyms

Isonicotinic acid is a pyridinemonocarboxylic acid in which the carboxy group is at position 4 of the pyridine ring. It has a role as a human metabolite and an algal metabolite. It is a conjugate acid of an isonicotinate.

Identifiers

Registry numbers, names and line notations, tap to copy

IUPAC name
pyridine-4-carboxylic acid
CAS number
55-22-1 CAS number cross-checkedOther or deprecated CAS: 163751-04-0
EC number
200-228-2
Molecular formula
C6H5NO2
UNII
Y8SYN761TQ
MDL number
MFCD00006429
INCI name
ISONIACIN
InChIKey
TWBYWOBDOCUKOW-UHFFFAOYSA-N
InChI
InChI=1S/C6H5NO2/c8-6(9)5-1-3-7-4-2-5/h1-4H,(H,8,9)
SMILES (canonical and isomeric)
C1=CN=CC=C1C(=O)O

Synonyms

  • 4-Pyridinecarboxylic acid
  • Pyridine-4-carboxylic acid
  • 4-Carboxypyridine
  • gamma-Picolinic acid
  • p-Pyridinecarboxylic acid
  • gamma-Pyridinecarboxylic acid
  • Acid, Isonicotinic
  • 4-Picolinic acid
  • Acide iso-nicotinique
  • 1,4-Dihydroisonicotinic acid
  • Nicotinic Acid EP Impurity E
  • pyridine, 4-carboxy-
  • isonicotinic-d4 acid
  • isonicotinicacid
  • Pyridine-4-carboxylic Acid (Isonicotinic Acid)
  • isonicotonic acid
  • Pyridine-4-carboxylic Acid, Nicotinic Acid Imp. E (EP), Isonicotinic Acid, Isoniazid Impurity A, Nicotinic Acid Impurity E
  • alpha-Picolinic acid
  • Isonicotinic acid, 99%
  • 4-pyridine-carboxylic acid
  • Biomol-NT_000289
  • Pyridinecarboxylic acid-(4)
  • 4-Pyridinecarboxylic acid, Pyridine-4-carboxylic acid
  • Isoniazid impurity a
  • Isonicotinic acid, purum, >=99.0% (T)
Show all 28 synonyms
  • Isonicotinic acid, SAJ special grade, >=99.0%
  • Isoniazid Impurity 2Nicotinic Acid EP Impurity E
  • Isonicotinic acid, Isoniazid, 4-pyridinecarboxylic acid, p-pyridinecarboxylic acid, 4-Picolinic acid

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

No measured properties are recorded for this substance yet. Ask suppliers for a technical data sheet.

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
123.11 g/molcalc.
Exact mass
123.032 Dacalc.
LogP (octanol/water)
0.78calc.
Topological polar surface area
50.19 Ųcalc.
Hydrogen bond donors
1calc.
Hydrogen bond acceptors
2calc.
Rotatable bonds
1calc.
Heavy atoms
9calc.
Rings
1calc.
Aromatic rings
1calc.
Fraction sp3 carbons
0calc.
Formal charge
0calc.
Stereocentres
0calc.
Lipinski rule of five
Passes (0 violations)calc.

Calculated for screening. Confirm critical figures with the supplier.

Murcko scaffold

The ring system that remains when every side chain is removed

Murcko scaffold of this chemical, c1ccncc1

c1ccncc1

1 ring, 6 atoms, the Pyridine ring system.

118,162 other chemicals share this scaffold

Safety and hazards

GHS classification summary, not a safety data sheet

GHS signal word
Warning
GHS07: Harmful or irritant
Harmful or irritant

Hazard statements

  • H315Causes skin irritation.
  • H319Causes serious eye irritation.
  • H335May cause respiratory irritation.
Precautionary statements (16)
  • P261Avoid breathing dust, fume, gas, mist, vapours or spray.
  • P264Wash skin thoroughly after handling.
  • P264 + P265Wash skin thoroughly after handling. Do not touch eyes.
  • P271Use only outdoors or in a well-ventilated area.
  • P280Wear protective gloves, protective clothing, eye protection and face protection.
  • P302 + P352If on skin: Wash with plenty of water.
  • P304 + P340If inhaled: Remove person to fresh air and keep comfortable for breathing.
  • P305 + P351 + P338If in eyes: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing.
  • P319Get medical help if you feel unwell.
  • P321Specific treatment (see supplemental first aid instructions on the label).
  • P332 + P317If skin irritation occurs: Get medical help.
  • P337 + P317If eye irritation persists: Get medical help.
  • P362 + P364Take off contaminated clothing. And wash it before reuse.
  • 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

Isonicotinic acid suppliers

Sponsored listings first, then the documented ranking: membership, verification, replies, completeness, freshness and ratings

All 89 suppliers
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Suppliers marked Unclaimed profile have not claimed their profile yet. They are not verified by CompoundList, their offers are price on request and details may have changed, so please confirm them with the supplier. Company representatives can claim a profile with a business email on the company's own website domain. Our team verifies each claim and sends the result by email.

Where suppliers are based

89 suppliers in 18 countries

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Isonicotinic acid price

Indicative price range per kg from live supplier offers

No published prices right now

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Uses and applications

What the substance is used for, by industry and function

Cosmetic ingredient, INCI name ISONIACIN(skin conditioning - miscellaneous)

Roles

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

Cosmetic functions

  • Skin conditioning - miscellaneous

Regulatory status

Inventories, regulations and trade controls that list this substance

Health and food

  • EU cosmetic ingredient inventory

United States

  • TSCA inventory (USA)
    Status: Active in US commerce

HS code and trade data

Customs classification and reported world trade statistics

Global trade

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

HS 2939.80Indicative HS code

Natural or reproduced by synthesis, and their salts, esters and other derivatives not elsewhere classified…

World exports in 2024
$49.3M
+13.2% vs 2023, imports $61.4M
2019 to 2024
Top exporters
  1. China31.7%
  2. India * partner reported23.1%
  3. South Africa7.8%
Top importers
  1. Austria28.6%
  2. United States11.9%
  3. United Kingdom7.9%

* Partner reported figures, a lower bound.

Reported customs values in USD, not prices.Full trade data

The HS code shown for Isonicotinic 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 Isonicotinic acid, based on the data on this page

What is Isonicotinic acid?

Isonicotinic acid is a pyridinemonocarboxylic acid in which the carboxy group is at position 4 of the pyridine ring. It has a role as a human metabolite and an algal metabolite. It is a conjugate acid of an isonicotinate.

What is the CAS number of Isonicotinic acid?

The CAS registry number of Isonicotinic acid is 55-22-1. Other or deprecated CAS numbers: 163751-04-0.

What is the molecular formula and weight of Isonicotinic acid?

The molecular formula of Isonicotinic acid is C6H5NO2 and its molar mass is 123.11 g/mol.

What is Isonicotinic acid used for?

Known uses and roles of Isonicotinic acid include skin conditioning agents in cosmetics and personal care, algal metabolite, animal metabolite, eukaryotic metabolite, human metabolite and 3 more.

Is Isonicotinic acid hazardous?

Isonicotinic acid carries the GHS signal word "Warning". Main hazards: causes skin irritation, causes serious eye irritation, may cause respiratory irritation. This summary is not an SDS, always read the supplier safety data sheet.

What is the HS code of Isonicotinic acid?

Isonicotinic acid is usually classified under HS code 293980 (Alkaloids, natural or reproduced by synthesis, and their salts, ethers, esters and other…). This is indicative, confirm it with your customs broker before shipping.

Where can I buy Isonicotinic acid?

CompoundList lists 89 suppliers of Isonicotinic acid in China, United States, Germany, Canada and 14 more. Send one free request to get and compare quotes. Your contact details stay private until you accept a quote.

Where can I buy Isonicotinic acid in India?

2 suppliers in India list Isonicotinic acid on CompoundList. Filter the suppliers list by country and send a request to compare prices, grades and delivery times.

What is the price of Isonicotinic acid?

Suppliers quote Isonicotinic 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 Isonicotinic 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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