Substance profile
Propionic Acid
Propionic Acid is colorless, oily liquid with a slightly pungent disagreeable, rancid odor.
01 · Identification
What Propionic Acid is
Propionic Acid is colorless, oily liquid with a slightly pungent disagreeable, rancid odor. Its molecular formula is C3H6O2 and its molecular weight is 74.08 g/mol. It boils at 141 °C, melts at -21.5 °C.
Under the GHS it carries the signal word Danger. It is classed as corrosives.
02 · Identifiers
Propionic Acid identifiers and molecular data
Propionic Acid CAS number and EC number
Propionic Acid molecular formula and molecular weight
Other names for Propionic Acid
- propionic acid … %
03 · GHS classification
Propionic Acid hazard classification
Harmonised classification under CLP Annex VI. This is the legally binding classification in the EU; other jurisdictions may differ.
Propionic Acid pictograms and signal word
Propionic Acid hazard class and category
| Hazard class | Category | From code | Pictogram |
|---|---|---|---|
| Skin corrosion/irritation GHS chapter 3.2 | Category 1A or 1B or 1C | H314 | GHS05 |
Where two values are shown with “or”, the hazard statement is shared by more than one category or by more than one class, and the code alone does not say which. H272, for example, belongs to oxidising liquids and to oxidising solids — the physical state decides. The binding answer for a specific entry is in the CLP Annex VI table itself.
Propionic Acid hazard statements (H-codes)
| Code | Hazard statement |
|---|---|
| H314 | Causes severe skin burns and eye damage. |
This page lists only the codes assigned to Propionic Acid. The full reference lives on the hazard statements hub, the precautionary statements hub and the GHS pictograms hub.
Safety Data Sheet
Getting an SDS for Propionic Acid
A Safety Data Sheet is written for a product, not for a substance: the supplier of the grade you actually buy issues it, so two suppliers of Propionic Acid issue two different sheets. That is why there is no single authoritative SDS for a substance to download — what there is, is the job of collecting the sheets for the products you hold and keeping them current as suppliers revise them.
04 · Precautionary statements
Propionic Acid precautionary statements
CLP Annex VI assigns 5 precautionary statements to Propionic Acid. They are grouped the way a label groups them: what to do before handling, what to do when something has already happened, how to store it and how to dispose of it.
Prevention
What to do before and during handling so the hazard never happens.
Response
What to do once exposure, spillage or fire has already happened.
Reading the notation. … is a blank the supplier fills in — not a truncated sentence.· [square brackets] mark a part printed only when it applies.
05 · Names in the regulation
Propionic Acid name in 23 EU languages
CLP Annex VI Part 3 is published in every language edition of the regulation, and the identification column is written out in each of them. Nothing below is translated by us: each line is the name as that edition prints it. Under Art. 18(2) the substance name from Annex VI is a lawful product identifier, so this is the wording to put on a label going to that market — and where the cell lists several designations, any one of them qualifies.
| Language | Name in CLP Annex VI Part 3 |
|---|---|
| Bulgarian български | пропионова киселина … % |
| Spanish español | Ácido propiónico al … % |
| Czech čeština | propionová kyselina …% |
| Danish dansk | propionsyre … % |
| German Deutsch | Propionsäure … % |
| Estonian eesti | propioonhape … % |
| Greek ελληνικά | προπιονικό οξύ … % |
| English English | propionic acid … % |
| French français | acide propionique à …% |
| Croatian hrvatski | propionska kiselina … % |
| Italian italiano | acido propionico … % |
| Latvian latviešu | propionskābe … % |
| Lithuanian lietuvių | …% propiono rūgštis |
| Hungarian magyar | propionsav … % |
| Maltese Malti | aċidu propjoniku … % |
| Dutch Nederlands | propionzuur … % |
| Polish polski | kwas propionowy … % kwas etanokarboksylowy … %kwas metylooctowy … % |
| Portuguese português | ácido propiónico a ... % |
| Romanian română | acid propionic ... % |
| Slovak slovenčina | propánová kyselina ... % |
| Slovenian slovenščina | propionska kislina ... % |
| Finnish suomi | propionihappo … % |
| Swedish svenska | propionsyra ... % |
All 23 language editions of Annex VI carry this entry. Irish is the twenty-fourth official EU language and has no line here for a different reason: no consolidated CLP text has ever been published in Irish, so there is no Irish edition of Annex VI to quote a name from. Source: consolidated CLP, CELEX 02008R1272, language editions. © European Union, https://eur-lex.europa.eu — only the electronic Official Journal of the European Union is authentic.
06 · Label elements
Propionic Acid GHS label elements
Everything CLP Annex VI fixes for Propionic Acid, laid out the way it appears on a label. The greyed lines are the parts only the supplier can fill in.
Danger
Propionic Acid
- Causes severe skin burns and eye damage.
- Do not breathe dust/fume/gas/mist/vapours/spray.
- Wear protective gloves/protective clothing/eye protection/face protection/hearing protection/…
- IF SWALLOWED:
- Immediately call a POISON CENTER/doctor/…
- Do NOT induce vomiting.
Supplier name, address and telephone number· Product identifier·Nominal quantity
Need this as an actual label? Open Propionic Acid in the GHS label constructor →
07 · Health hazards
Propionic Acid health hazards and exposure limits
Propionic Acid hazard summary
Liquid causes second degree burns after contact for a few minutes. [CHRIS] Corrosive to skin; [Quick CPC] [Acute irritant contact dermatitis from propionic acid used in animal feed preservation. Contact Dermatitis. Henschel R, et al. 1999 Jun;40(6):328. No abstract available.] A skin, eye, and respiratory tract irritant; [ICSC]
Source: Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
Propionic Acid occupational exposure limits
| Limit | Value | Source |
|---|---|---|
| PEL | none See Appendix G | The National Institute for Occupational Safety and Health (NIOSH) |
| REL | 10 ppm (30 mg/m³) | Occupational Safety and Health Administration (OSHA) |
| REL | 15 ppm (45 mg/m³) | Occupational Safety and Health Administration (OSHA) |
| REL | TWA 10 ppm (30 mg/m3) ST 15 ppm (45 mg/m3) | The National Institute for Occupational Safety and Health (NIOSH) |
| IDLH | N.D. | The National Institute for Occupational Safety and Health (NIOSH) |
These are United States values. The European Union sets its own indicative and binding limits, and the figure that applies at a given workplace is the one in the local regulation — not the one shown here.
08 · Physical and chemical properties
Propionic Acid properties
Every value is shown with the conditions it was measured under and the source it came from. Where sources disagree, all values are listed rather than one being picked — the difference is usually a different form of the substance, not an error.
Propionic Acid boiling point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Boiling point | 141.1 °C (286 °F) | HSDB | |
| 141.11 °C (286 °F) | NIOSH | ||
| 140.72 °C (285.3 °F) | at 760 mmHg | CAMEO |
Propionic Acid melting point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Melting point | -21.5 °C (-6.7 °F) | HSDB | |
| -15 °C (5 °F) | NIOSH |
Propionic Acid density
| Property | Value | Conditions | Source |
|---|---|---|---|
| Density | 0.315 g/cm³ | HSDB | |
| 0.99 g/cm³ | NIOSH | ||
| 0.993 g/cm³ | at 20 °C | HSDB |
Propionic Acid solubility
| Property | Value | Conditions | Source |
|---|---|---|---|
| Solubility | Sol in alcohol, ether, chloroform. | HSDB | |
| Miscible with ethanol; soluble in diethyl ether; slightly soluble in chloroform | HSDB |
Propionic Acid vapor pressure
| Property | Value | Conditions | Source |
|---|---|---|---|
| Vapor pressure | 3 mmHg | NIOSH | |
| 2.9 mmHg | at 20 °C | CAMEO | |
| 3.53 mmHg | at 25 °C | HSDB |
Propionic Acid flash point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Flash point | 52.22 °C (126 °F) | HSDB | |
| 54.44 °C (130 °F) | CAMEO |
Propionic Acid autoignition temperature
| Property | Value | Conditions | Source |
|---|---|---|---|
| Autoignition temperature | 465.56 °C (870 °F) | HSDB | |
| 485 °C (905 °F) | ICSC |
Propionic Acid lower explosive limit (LEL)
| Property | Value | Conditions | Source |
|---|---|---|---|
| Lower explosive limit (LEL) | 2.9 % by volume | HSDB |
Propionic Acid upper explosive limit (UEL)
| Property | Value | Conditions | Source |
|---|---|---|---|
| Upper explosive limit (UEL) | 12.1 % by volume | HSDB | |
| 14.8 % by volume | CAMEO |
Propionic Acid vapor density
| Property | Value | Conditions | Source |
|---|---|---|---|
| Vapor density | 2.56 (air = 1) | HSDB | |
| 2.6 (air = 1) | ICSC |
Propionic Acid odor threshold
| Property | Value | Conditions | Source |
|---|---|---|---|
| Odor threshold | Odor threshold: 0.16 ul/l; Odor safety class B; B= 50-90% of distracted persons perceive warning of TLV. | HSDB | |
| 0.0840 mg/cu m (odor low); 60.00 mg/cu m (odor high). | HSDB | ||
| Odor Threshold Low: 0.02 [ppm] | Haz-Map |
Propionic Acid critical temperature and pressure
| Property | Value | Conditions | Source |
|---|---|---|---|
| Critical temperature and pressure | 338.9 °C (642 °F) | HSDB |
Propionic Acid corrosivity
| Property | Value | Conditions | Source |
|---|---|---|---|
| Corrosivity | CORROSIVE | HSDB |
Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.
09 · Fire and explosion
Propionic Acid fire and explosion behaviour
These are descriptions rather than measured values, so they are kept out of the table above and quoted here with the source that reported them.
Propionic Acid fire potential
Flammable liquid. Highly flammable when exposed to heat, flame, or oxidizers.
Source: Hazardous Substances Data Bank (HSDB)
10 · Handling and storage
Propionic Acid storage and handling
Propionic Acid safe storage
Fireproof. Separated from strong oxidants and strong bases. Store only in original container. Store in an area without drain or sewer access.
Source: ILO-WHO International Chemical Safety Cards (ICSCs)
Propionic Acid storage conditions
Outside or detached storage is preferred. Store in a cool, dry, well-ventilated location.
Source: Hazardous Substances Data Bank (HSDB)
Propionic Acid incompatible materials
Alkalis, strong oxidizers (e.g., chromium trioxide) [Note: Corrosive to steel].
Source: Hazardous Substances Data Bank (HSDB)
Propionic Acid reactivity
PROPIONIC ACID is a colorless, oily liquid, moderately toxic, corrosive. Flammable when exposed to heat, flame or oxidizers. When heated to decomposition it emits acrid smoke and irritating fumes [Lewis, 3rd ed., 1993, p. 1090].
Source: CAMEO Chemicals
Planning storage for a mix of chemicals? Check Propionic Acid in the storage compatibility matrix →
11 · Transport
Propionic Acid UN number and transport classification
Transport classification is a separate system from the GHS classification above. It decides how a package is marked and how a load may be carried; it does not follow from the workplace label, and the workplace label does not follow from it. The entries below are linked by CAS number, never by name.
The same CAS number is shipped under more than one UN number. Which entry applies follows from the form and the concentration of the consignment — read the proper shipping name, not the CAS.
Propionic Acid under UN 1848 — shipping name, class and packing group
Europe · ADR 2025, Table A
| Proper shipping name (3.1.2) | Class | Classification code | PG | Labels (column 5) |
|---|---|---|---|---|
| PROPIONIC ACID with not less than 10 % and less than 90 % acid by mass | 8 | C3 | III | |
Source: ADR 2025, Table A of Chapter 3.2 · ECE/TRANS/352 Vol. I (UNECE). Class 8 is “Corrosive substances” (ADR 2.1.1.1).
United States · 49 CFR 172.101 Hazardous Materials Table
| Proper shipping name (column 2) | Class or division | PG | Labels (column 6) |
|---|---|---|---|
| Propionic acid with not less than 10% and less than 90% acid by mass | 8 | III | |
Source: 49 CFR 172.101 Hazardous Materials Table · eCFR, revision 2026-08-03. Class 8 is “Corrosive material” (49 CFR 173.2).
Propionic Acid under UN 3463 — shipping name, class and packing group
Europe · ADR 2025, Table A
| Proper shipping name (3.1.2) | Class | Classification code | PG | Labels (column 5) |
|---|---|---|---|---|
| PROPIONIC ACID with not less than 90 % acid by mass | 8 | CF1 | II | |
Source: ADR 2025, Table A of Chapter 3.2 · ECE/TRANS/352 Vol. I (UNECE). Class 8 is “Corrosive substances” (ADR 2.1.1.1).
United States · 49 CFR 172.101 Hazardous Materials Table
| Proper shipping name (column 2) | Class or division | PG | Labels (column 6) |
|---|---|---|---|
| Propionic acid with not less than 90% acid by mass | 8 | II | |
Source: 49 CFR 172.101 Hazardous Materials Table · eCFR, revision 2026-08-03. Class 8 is “Corrosive material” (49 CFR 173.2).
12 · Questions
Propionic Acid — frequently asked questions
What is the CAS number of Propionic Acid?
The CAS number of Propionic Acid is 79-09-4. Its EC number is 201-176-3.
What is the chemical formula of Propionic Acid?
The molecular formula of Propionic Acid is C3H6O2 and its molecular weight is 74.08 g/mol.
What does a Propionic Acid label have to show?
Under CLP Annex VI the label for Propionic Acid carries the pictogram Corrosion and the signal word is Danger.
Is Propionic Acid flammable?
CLP Annex VI assigns Propionic Acid no flammability hazard class. That is not a statement that it cannot burn: the harmonised list only records the hazards that were assessed for it. The flash point reported for it is 52.22 °C (126 °F) (HSDB).
Is Propionic Acid a carcinogen?
CLP Annex VI records no harmonised carcinogenicity classification for Propionic Acid. Annex VI is a list of agreed classifications, not a list of substances found safe, so this is an absence of a classification rather than a clean bill of health.
What is the exposure limit for Propionic Acid?
The US occupational exposure limit reported for Propionic Acid is none See Appendix G (The National Institute for Occupational Safety and Health (NIOSH)). Limits differ by country: the EU sets its own indicative and binding values, and the figure that applies at a given workplace is the one in the local regulation.
What is the boiling point of Propionic Acid?
The boiling point reported for Propionic Acid is 141.1 °C (286 °F) (HSDB).
What is the melting point of Propionic Acid?
The melting point reported for Propionic Acid is -21.5 °C (-6.7 °F) (HSDB).
How should Propionic Acid be stored?
Outside or detached storage is preferred. Store in a cool, dry, well-ventilated location. (Hazardous Substances Data Bank (HSDB))
Nearby
Substances next to Propionic Acid
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