Substance profile
Methacrylic Acid
Methacrylic Acid is clear colorless liquid or colorless crystals with an acrid, repulsive odor.
01 · Identification
What Methacrylic Acid is
Methacrylic Acid is clear colorless liquid or colorless crystals with an acrid, repulsive odor. Its molecular formula is C4H6O2 and its molecular weight is 86.09 g/mol. It boils at 163 °C, melts at 16 °C, is soluble in water.
Under the GHS it carries the signal word Danger. It is classed as corrosives.
02 · Identifiers
Methacrylic Acid identifiers and molecular data
Methacrylic Acid CAS number and EC number
Methacrylic Acid molecular formula and molecular weight
Other names for Methacrylic Acid
- 2-methylpropenoic acid
03 · GHS classification
Methacrylic Acid hazard classification
Harmonised classification under CLP Annex VI. This is the legally binding classification in the EU; other jurisdictions may differ.
Methacrylic Acid pictograms and signal word
Methacrylic Acid hazard class and category
| Hazard class | Category | From code | Pictogram |
|---|---|---|---|
| Acute toxicity - oral GHS chapter 3.1 | Category 4 | H302 | GHS07 |
| Acute toxicity - dermal GHS chapter 3.1 | Category 4 | H312 | GHS07 |
| 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.
Methacrylic Acid hazard statements (H-codes)
| Code | Hazard statement |
|---|---|
| H312 | Harmful in contact with skin. |
| H302 | Harmful if swallowed. |
| H314 | Causes severe skin burns and eye damage. |
This page lists only the codes assigned to Methacrylic 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 Methacrylic 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 Methacrylic 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
Methacrylic Acid precautionary statements
CLP Annex VI assigns 10 precautionary statements to Methacrylic 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
Methacrylic 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 | метакрилова киселина 2-метилпропенова киселина |
| Spanish español | Ácido metacrílico ácido 2-metilpropenoico |
| Czech čeština | methakrylová kyselina 2- methylpropenová kyselina |
| Danish dansk | methacrylsyre 2-methylpropensyre |
| German Deutsch | Methacrylsäure 2-Methylpropensäure |
| Estonian eesti | metakrüülhape 2-metüülpropeenhape |
| Greek ελληνικά | μεθακρυλικό οξύ 2-μεθυλοπροπενικό οξύ |
| English English | methacrylic acid 2-methylpropenoic acid |
| French français | acide méthacrylique acide 2-méthylpropénoïque |
| Croatian hrvatski | metakrilna kiselina 2-metilpropenska kiselina |
| Italian italiano | acido 2-metil propenoico |
| Latvian latviešu | metakrilskābe 2-metilpropēnskābe |
| Lithuanian lietuvių | metakrilo rūgštis 2-metilpropeno rūgštis |
| Hungarian magyar | metakrilsav 2-metilpropénsav |
| Maltese Malti | aċidu metakriliku aċidu 2-metilpropenojku |
| Dutch Nederlands | methacrylzuur 2-methylpropenzuur |
| Polish polski | kwas metakrylowy kwas 2-metylopropenowy |
| Portuguese português | ácido metacrílico ácido 2-metilpropenóico |
| Romanian română | acid metacrilic acid 2-metil propenoic |
| Slovak slovenčina | kyselina metakrylová kyselina 2-metylpropénová |
| Slovenian slovenščina | metakrilna kislina 2-metilpropenojska kislina |
| Finnish suomi | metakryylihappo 2-metyylipropeenihappo |
| Swedish svenska | metakrylsyra 2-metylpropensyra |
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
Methacrylic Acid GHS label elements
Everything CLP Annex VI fixes for Methacrylic Acid, laid out the way it appears on a label. The greyed lines are the parts only the supplier can fill in.
Danger
Methacrylic Acid
- Harmful in contact with skin.
- Harmful if swallowed.
- Causes severe skin burns and eye damage.
- Do not breathe dust/fume/gas/mist/vapours/spray.
- Do not eat, drink or smoke when using this product.
- Wear protective gloves/protective clothing/eye protection/face protection/hearing protection/…
- IF SWALLOWED:
- IF ON SKIN:
- Immediately call a POISON CENTER/doctor/…
- Call a POISON CENTER/doctor/… if you feel unwell.
- Rinse mouth.
- Do NOT induce vomiting.
- Wash with plenty of water/…
Supplier name, address and telephone number· Product identifier·Nominal quantity
Need this as an actual label? Open Methacrylic Acid in the GHS label constructor →
07 · Health hazards
Methacrylic Acid health hazards and exposure limits
Methacrylic Acid hazard summary
Methacrylic acid can cause skin burns and, after acute heavy inhalation exposure, pulmonary edema. [ICSC] Causes second degree burns after a few minutes skin exposure; [CHRIS] Corrosive to skin; [Quick CPC] Methacrylic acid was negative in skin sensitization testing; [Reference #1] Methacrylic acid, stabilized (UN2531) has warning of explosive polymerization; [ERG 2016]
Source: Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
Methacrylic Acid occupational exposure limits
| Limit | Value | Source |
|---|---|---|
| PEL | none See Appendix G | The National Institute for Occupational Safety and Health (NIOSH) |
| REL | 20 ppm (70 mg/m³) | Occupational Safety and Health Administration (OSHA) |
| REL | TWA 20 ppm (70 mg/m3) [skin] | 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
Methacrylic 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.
Methacrylic Acid boiling point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Boiling point | 163 °C (325.4 °F) | at 760 mmHg | HSDB |
| 162.78 °C (325 °F) | NIOSH | ||
| 162.78 °C (325 °F) | at 760 mmHg | CAMEO |
Methacrylic Acid melting point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Melting point | 16 °C (60.8 °F) | HSDB | |
| 16.11 °C (61 °F) | NIOSH |
Methacrylic Acid density
| Property | Value | Conditions | Source |
|---|---|---|---|
| Density | 1.02 g/cm³ | Liquid | NIOSH |
| 1.0153 g/cm³ | at 20 °C | HSDB | |
| 1.015 g/cm³ | at 20 °C | CAMEO |
Methacrylic Acid solubility
| Property | Value | Conditions | Source |
|---|---|---|---|
| Solubility | Soluble in chloroform; miscible with ethanol, ether | HSDB | |
| In water solubility, 89 g/L at 20 °C | at 20 °C | HSDB | |
| (77 °F): 9% | at 25 °C | NIOSH |
Methacrylic Acid vapor pressure
| Property | Value | Conditions | Source |
|---|---|---|---|
| Vapor pressure | 0.7 mmHg | NIOSH | |
| 0.65 mmHg | at 20 °C | CAMEO | |
| 0.99 mmHg | at 25 °C | HSDB |
Methacrylic Acid flash point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Flash point | 76 °C (168.8 °F) | open cup | HSDB |
| 67.22 °C (153 °F) | HSDB | ||
| 77.22 °C (171 °F) | NIOSH |
Methacrylic Acid autoignition temperature
| Property | Value | Conditions | Source |
|---|---|---|---|
| Autoignition temperature | 400 °C (752 °F) | HSDB |
Methacrylic Acid lower explosive limit (LEL)
| Property | Value | Conditions | Source |
|---|---|---|---|
| Lower explosive limit (LEL) | 1.6 % by volume | HSDB | |
| 2.4 % by volume | CAMEO |
Methacrylic Acid upper explosive limit (UEL)
| Property | Value | Conditions | Source |
|---|---|---|---|
| Upper explosive limit (UEL) | 8.8 % by volume | HSDB | |
| 2.4 % by volume | OSHA |
Methacrylic Acid vapor density
| Property | Value | Conditions | Source |
|---|---|---|---|
| Vapor density | 2.97 (air = 1) | HSDB |
Methacrylic Acid critical temperature and pressure
| Property | Value | Conditions | Source |
|---|---|---|---|
| Critical temperature and pressure | 370 °C (698 °F) | HSDB |
Methacrylic Acid corrosivity
| Property | Value | Conditions | Source |
|---|---|---|---|
| Corrosivity | Forms corrosive liquid at melting point | HSDB |
Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.
09 · Fire and explosion
Methacrylic 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.
Methacrylic Acid fire potential
Flammable when exposed to heat, flame, or oxidizers.
Source: Hazardous Substances Data Bank (HSDB)
10 · Handling and storage
Methacrylic Acid storage and handling
Methacrylic Acid safe storage
Separated from strong oxidants and food and feedstuffs. Cool. Keep in the dark. Keep in a well-ventilated room. Store only if stabilized. Store only in original container.
Source: ILO-WHO International Chemical Safety Cards (ICSCs)
Methacrylic Acid storage conditions
Prior to working with this chemical you should be trained on its proper handling and storage. Before entering confined space where this chemical may be present, check to make sure that an explosive concentration does not exist. Store in tightly closed containers in a cool, well ventilated area away from oxidizers (such as perchlorates, peroxides, permanganates, chlorates and nitrates). Methacrylic acid should be stored at temperatures below 15 degrees C. Sources of ignition such as smoking and open flames are prohibited where Methacrylic acid is handled, used, or stored. Wherever Methacrylic acid is used, handled, manufactured, or stored, use explosion-proof electrical equipment and fittings.
Source: Hazardous Substances Data Bank (HSDB)
Methacrylic Acid incompatible materials
Oxidizers, elevated temperatures, hydrochloric acid [Note: Typically contains 100 ppm of the monomethyl ether of hydroquinone to prevent polymerization].
Source: Hazardous Substances Data Bank (HSDB)
Methacrylic Acid reactivity
METHACRYLIC ACID reacts with strong oxidizing agents. Presents a storage hazard: violent exothermic polymerizations leading to explosion can occur spontaneously, particularly at low inhibitor or stabilizer concentrations [Anon., CISHC Chem. Safety Summ., 1979, 50, p. 34; Bond, J., Loss Prev. Bull., 1991, 101, p. 1].
Source: CAMEO Chemicals
Planning storage for a mix of chemicals? Check Methacrylic Acid in the storage compatibility matrix →
11 · Transport
Methacrylic 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.
Methacrylic Acid under UN 2531 — shipping name, class and packing group
Europe · ADR 2025, Table A
| Proper shipping name (3.1.2) | Class | Classification code | PG | Labels (column 5) |
|---|---|---|---|---|
| METHACRYLIC ACID, STABILIZED | 8 | C3 | 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) |
|---|---|---|---|
| Methacrylic acid, stabilized | 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
Methacrylic Acid — frequently asked questions
What is the CAS number of Methacrylic Acid?
The CAS number of Methacrylic Acid is 79-41-4. Its EC number is 201-204-4.
What is the chemical formula of Methacrylic Acid?
The molecular formula of Methacrylic Acid is C4H6O2 and its molecular weight is 86.09 g/mol.
What does a Methacrylic Acid label have to show?
Under CLP Annex VI the label for Methacrylic Acid carries the pictograms Corrosion and Exclamation mark and the signal word is Danger.
Is Methacrylic Acid flammable?
CLP Annex VI assigns Methacrylic 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 76 °C (168.8 °F), open cup (HSDB).
Is Methacrylic Acid a carcinogen?
CLP Annex VI records no harmonised carcinogenicity classification for Methacrylic 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 Methacrylic Acid?
The US occupational exposure limit reported for Methacrylic 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 Methacrylic Acid?
The boiling point reported for Methacrylic Acid is 163 °C (325.4 °F), at 760 mmHg (HSDB).
What is the melting point of Methacrylic Acid?
The melting point reported for Methacrylic Acid is 16 °C (60.8 °F) (HSDB).
How should Methacrylic Acid be stored?
Prior to working with this chemical you should be trained on its proper handling and storage. Before entering confined space where this chemical may be present, check to make sure that an explosive concentration does not exist. Store in tightly closed containers in a cool, well ventilated area away from oxidizers (such as perchlorates, peroxides, permanganates, chlorates and nitrates). Methacrylic acid should be stored at temperatures below 15 degrees C. Sources of ignition such as smoking and open flames are prohibited where Methacrylic acid is handled, used, or stored. Wherever Methacrylic acid is used, handled, manufactured, or stored, use explosion-proof electrical equipment and fittings. (Hazardous Substances Data Bank (HSDB))
Nearby
Substances next to Methacrylic Acid
Keep going: substances starting with M, or search the whole database by name, CAS number, pictogram or signal word.