Provenance

Reference data from EU CLP Annex VI and published regulations — verify against your supplier's SDS before use.

Build a label

Substance profile

Maleic Acid

Maleic Acid is monoclinic prisms from water with a faint acidulous odor.

CAS 110-16-7 Warning

01 · Identification

What Maleic Acid is

Maleic Acid is monoclinic prisms from water with a faint acidulous odor. It boils at 135 °C, melts at 133 °C.

Under the GHS it carries the signal word Warning.

02 · Identifiers

Maleic Acid identifiers and molecular data

Maleic Acid CAS number and EC number

CAS number110-16-7
EC number203-742-5
Index number (CLP Annex VI)607-095-00-3

03 · GHS classification

Maleic Acid hazard classification

Harmonised classification under CLP Annex VI. This is the legally binding classification in the EU; other jurisdictions may differ.

Maleic Acid pictograms and signal word

Signal wordWarning

Maleic Acid hazard class and category

GHS hazard classes Maleic Acid falls into
Hazard class Category From code Pictogram
Acute toxicity - oral GHS chapter 3.1 Category 4 H302 GHS07
Skin corrosion/irritation GHS chapter 3.2 Category 2 H315 GHS07
Serious eye damage/eye irritation GHS chapter 3.3 Category 2A H319 GHS07
Skin sensitisation GHS chapter 3.4 Category 1 or 1A or 1B H317 GHS07
Specific target organ toxicity - single exposure GHS chapter 3.8 Category 3 H335 GHS07

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.

Maleic Acid hazard statements (H-codes)

Hazard statements assigned to Maleic Acid
CodeHazard statement
H302 Harmful if swallowed.
H335 May cause respiratory irritation.
H315 Causes skin irritation.
H319 Causes serious eye irritation.
H317 May cause an allergic skin reaction.

This page lists only the codes assigned to Maleic 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 Maleic 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 Maleic 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

Maleic Acid precautionary statements

CLP Annex VI assigns 16 precautionary statements to Maleic 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.

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

Maleic 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 малеинова киселина
Spanish español Ácido maleico
Czech čeština maleinová kyselina ( Z )-but-2-endiová kyselina
Danish dansk maleinsyre
German Deutsch Maleinsäure
Estonian eesti maleiinhape
Greek ελληνικά μηλεϊνικό οξύ
English English maleic acid
French français acide maléique
Croatian hrvatski maleinska kiselina
Italian italiano acido maleico
Latvian latviešu maleīnskābe
Lithuanian lietuvių maleino rūgštis
Hungarian magyar maleinsav
Maltese Malti aċidu malejku
Dutch Nederlands maleïnezuur
Polish polski kwas maleinowy
Portuguese português ácido maleico
Romanian română acid maleic
Slovak slovenčina kyselina maleínová
Slovenian slovenščina maleinska kislina
Finnish suomi maleiinihappo
Swedish svenska maleinsyra

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

Maleic Acid GHS label elements

Everything CLP Annex VI fixes for Maleic Acid, laid out the way it appears on a label. The greyed lines are the parts only the supplier can fill in.

GHS07 Exclamation mark pictogram

Warning

Maleic Acid

  • Harmful if swallowed.
  • May cause respiratory irritation.
  • Causes skin irritation.
  • Causes serious eye irritation.
  • May cause an allergic skin reaction.
  • Avoid breathing dust/fume/gas/mist/vapours/spray.
  • Wash thoroughly after handling.
  • Do not eat, drink or smoke when using this product.
  • Contaminated work clothing should not be allowed out of the workplace.
  • Wear protective gloves/protective clothing/eye protection/face protection/hearing protection/
  • IF SWALLOWED:
  • IF ON SKIN:
  • IF IN EYES:
  • Call a POISON CENTER/doctor/ if you feel unwell.
  • Get medical advice/attention.
  • Rinse mouth.
  • If skin irritation occurs:
  • If skin irritation or rash occurs:
  • If eye irritation persists:
  • Remove contact lenses, if present and easy to do. Continue rinsing.
  • Wash with plenty of water/

Supplier name, address and telephone number· Product identifier·Nominal quantity

Need this as an actual label? Open Maleic Acid in the GHS label constructor →

07 · Health hazards

Maleic Acid health hazards and exposure limits

Maleic Acid hazard summary

A strong irritant; [Merck Index] A severe skin, eye, and respiratory tract irritant; May cause kidney damage; [ICSC] A skin, eye, nose, and throat irritant; [HSDB] High concentrations may have corrosive effects to skin and eyes; [CHEMINFO] A skin irritant; Corrosive to eyes; [eChemPortal: ERMA] A skin, eye, and respiratory tract irritant; [eChemPortal: ESIS] An irritant; May cause serious injury to eyes; [MSDSonline]

Source: Haz-Map, Information on Hazardous Chemicals and Occupational Diseases

08 · Physical and chemical properties

Maleic 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.

Maleic Acid boiling point

Property Value Conditions Source
Boiling point 135 °C (275 °F) decomposes, at 760 mmHg CAMEO

Maleic Acid melting point

Property Value Conditions Source
Melting point 132.5 °C (270.5 °F) Melting point / Melting Range HSDB
287 °C (548.6 °F) HSDB
131 °C (267.8 °F) ICSC

Maleic Acid density

Property Value Conditions Source
Density 1.59 g/cm³ ICSC
1.59 g/cm³ at 20 °C HSDB

Maleic Acid solubility

Property Value Conditions Source
Solubility In water, 788 g/L at 25 °C, 3926 g/L at 97.5 °C at 25 °C HSDB
79.000 lb/100 lb water at 77 °F at 25 °C HSDB
In water, 441,000 mg/L at 25 °C at 25 °C HSDB

Maleic Acid vapor pressure

Property Value Conditions Source
Vapor pressure 0.0000134 mmHg at 25 °C HSDB
0.000036 mmHg at 25 °C ICSC
0.0000359 mmHg at 25 °C DOE PAC

Maleic Acid flash point

Property Value Conditions Source
Flash point 127 °C (260.6 °F) ICSC

Maleic Acid vapor density

Property Value Conditions Source
Vapor density 4 (air = 1) HSDB

Maleic Acid corrosivity

Property Value Conditions Source
Corrosivity May corrode metals when wet. HSDB

Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.

09 · Fire and explosion

Maleic 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.

Maleic Acid fire potential

Combustible when exposed to heat or flame.

Source: Hazardous Substances Data Bank (HSDB)

10 · Handling and storage

Maleic Acid storage and handling

Maleic Acid safe storage

Provision to contain effluent from fire extinguishing. Separated from food and feedstuffs. Dry. Store only in original packaging.

Source: ILO-WHO International Chemical Safety Cards (ICSCs)

Maleic Acid storage conditions

Keep container tightly closed in a dry and well-ventilated place. Keep in a dry place. Storage class (TRGS 510): Non Combustible Solids

Source: Hazardous Substances Data Bank (HSDB)

Maleic Acid incompatible materials

Oxidizing agents

Source: Hazardous Substances Data Bank (HSDB)

Maleic Acid reactivity

MALEIC ACID is a colorless to white crystalline solid. Moderately toxic. When heated to decomposition it emits irritating fumes and acrid smoke [Lewis, 3rd ed., 1993, p. 790].

Source: CAMEO Chemicals

Planning storage for a mix of chemicals? Check Maleic Acid in the storage compatibility matrix →

11 · Questions

Maleic Acid — frequently asked questions

What is the CAS number of Maleic Acid?

The CAS number of Maleic Acid is 110-16-7. Its EC number is 203-742-5.

What does a Maleic Acid label have to show?

Under CLP Annex VI the label for Maleic Acid carries the pictogram Exclamation mark and the signal word is Warning.

Is Maleic Acid flammable?

CLP Annex VI assigns Maleic 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 127 °C (260.6 °F) (ICSC).

Is Maleic Acid a carcinogen?

CLP Annex VI records no harmonised carcinogenicity classification for Maleic 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 boiling point of Maleic Acid?

The boiling point reported for Maleic Acid is 135 °C (275 °F), decomposes, at 760 mmHg (CAMEO).

What is the melting point of Maleic Acid?

The melting point reported for Maleic Acid is 132.5 °C (270.5 °F), Melting point / Melting Range (HSDB).

How should Maleic Acid be stored?

Keep container tightly closed in a dry and well-ventilated place. Keep in a dry place. Storage class (TRGS 510): Non Combustible Solids (Hazardous Substances Data Bank (HSDB))

Nearby

Substances next to Maleic Acid

Keep going: substances starting with M, or search the whole database by name, CAS number, pictogram or signal word.

Get the free GHS / CLP / OSHA deadline calendar

Verified 2026–2029 compliance dates in one PDF — plus alerts when the rules change.