Download SDS
CAS No.: 110-16-7
Check the Maleic acid product page for in-depth specifications, including solubility, stock solutions, MOA, and working concentrations.

Quick Safety Reference

🛡️ Hazard Overview

  • GHS Class: GHS05; GHS07; GHS08
  • Signal Word: Danger
  • Hazard Statements: H302; H312; H315; H317; H318; H319; H335; H370; H402

🧤 PPE Guidelines

  • Gloves: Chemical‑resistant gloves suggested
  • Eye Protection: Safety goggles suggested
  • Respirator: Dust respirator if dust occurs

❄️ Storage

  • Storage Temp: -20°C (-4°F) Keep dry

🚑 Emergency First Aid

  • For inhalation, skin, eye or ingestion exposure, please refer to full SDS Section 4.

GHS 16 Safety Standard Sections

Product identifier

  • Product Name: Maleic acid
  • Catalog Number: S3086
  • CAS Number: 110-16-7
  • IUPAC Name: 2-​Butenedioic acid (2Z)​-

Relevant identified uses and uses advised against

  • Identified uses: For research and development use only; laboratory chemicals; manufacture of substances.
  • Uses advised against: Not for pharmaceutical, household, or other unapproved uses.

Details of the supplier

  • Company: Selleck Chemicals
  • TollFree: +1 877 796-6397
  • Tel: +1 832 582-8158
  • Fax: +1 832 582-8590

Emergency telephone number

  • Emergency phone #: +1 832 582-8158

2.1 GHS classification in accordance with 29 CFR 1910 (OSHA HCS):
Acute toxicity (oral): Category 4. H302
Acute toxicity (dermal): Category 4. H312
Skin irritation: Category 2. H315
Skin sensitization: Category 1. H317
Serious eye damage: Category 1. H318
Serious eye irritation: Category 2. H319
Specific target organ toxicity (single exposure): Category 3. H335
Specific target organ toxicity (single exposure): Category 1. H370
Acute aquatic toxicity: Category 3. H402

2.2 GHS Label elements, including precautionary statements
Hazard Pictogram(s):
GHS05 GHS07 GHS08
Signal Word:
Danger
Hazard statement(s):
H302: Harmful if swallowed
H312: Harmful in contact with skin
H315: Causes skin irritation
H317: May cause an allergic skin reaction
H318: Causes serious eye damage
H319: Causes serious eye irritation
H335: May cause respiratory irritation
H370: Causes damage to organs
H402: Harmful to aquatic life
Precautionary statement(s):
Prevention:
P260: Do not breathe dust/fume/gas/mist/vapors/spray.
P261: Avoid breathing dust/fume/gas/mist/vapors/spray.
P264: Wash hands thoroughly after handling.
P264+P265: Wash hands thoroughly after handling. Do not touch eyes.
P270: Do not eat, drink or smoke when using this product.
P271: Use only outdoors or in a well-ventilated area.
P272: Contaminated work clothing should not be allowed out of the workplace.
P273: Avoid release to the environment.
P280: Wear protective gloves/protective clothing/eye protection/face protection/hearing protection.
Response:
P301+P317: IF SWALLOWED: Get medical help.
P302+P352: IF ON SKIN: wash with plenty of water.
P304+P340: IF INHALED: Remove person to fresh air and keep comfortable for breathing.
P305+P351: IF IN EYES: Rinse cautiously with water for several minutes.
P305+P354: IF IN EYES: Immediately rinse with water for several minutes.
P308+P316: IF exposed or concerned: Get emergency medical help immediately.
P317: Get emergency medical help.
P319: Get medical help if you feel unwell.
P321: Specific treatment (see information on this label and safety datasheet)).
P330: Rinse mouth.
P332+P317: If skin irritation occurs: Get medical help.
P333+P317: If skin irritation or rash occurs: Get medical help.
P337+P317: If eye irritation persists: Get medical help.
P338: Remove contact lenses, if present and easy to do. Continue rinsing.
P362+P364: Take off contaminated clothing and wash it before reuse.
Storage:
P403+P233: Store in a well-ventilated place. Keep container tightly closed.
P405: Store locked up.
Disposal:
P501: P501 Dispose of contents/ container to an approved waste disposal plant.

2.3 Other hazards
None.

3.1 Substances
Product name: Maleic acid
CAS Number: 110-16-7
PubChem CID: 444266

3.2 Mixtures
Not applicable (pure substance).

4.1 Description of first aid measures
Inhalation: Fresh air, rest. Refer for medical attention.
Skin contact: Wear protective gloves when administering first aid. Remove contaminated clothes. Rinse skin with plenty of water or shower.
Eye contact: First rinse with plenty of water for several minutes (remove contact lenses if easily possible), then refer for medical attention.
Ingestion: Rinse mouth. Give one or two glasses of water to drink. Refer for medical attention .

4.2 Most important symptoms and effects, both acute and delayed
See Section 11 (Toxicological Information).

4.3 Indication of any immediate medical attention and special treatment needed
Treat symptomatically. Contact a poison control center or physician for severe exposure.

5.1 Extinguishing media
Suitable: Water spray, dry chemical, carbon dioxide (CO2), alcohol-resistant foam.
Unsuitable: None known.

5.2 Specific hazards arising from the substance or mixture
Excerpt from ERG Guide 156 [Substances - Toxic and/or Corrosive (Combustible / Water-Sensitive)]:
Note: Most foams will react with the material and release corrosive/toxic gases. CAUTION: For Acetyl bromide (UN1716), use CO2 or dry chemical only.
SMALL FIRE: CO2, dry chemical, dry sand, alcohol-resistant foam.
LARGE FIRE: Water spray, fog or alcohol-resistant foam. FOR CHLOROSILANES, DO NOT USE WATER; use alcohol-resistant foam. If it can be done safely, move undamaged containers away from the area around the fire. Avoid aiming straight or solid streams directly onto the product.
FIRE INVOLVING TANKS, RAIL TANK CARS OR HIGHWAY TANKS: Fight fire from maximum distance or use unmanned master stream devices or monitor nozzles. Do not get water inside containers. Cool containers with flooding quantities of water until well after fire is out. Withdraw immediately in case of rising sound from venting safety devices or discoloration of tank. ALWAYS stay away from tanks in direct contact with flames. (ERG, 2024)
Use water spray, powder, foam, carbon dioxide.
Wear self-contained breathing apparatus for firefighting if necessary.
Use water spray, alcohol-resistant foam, dry chemical or carbon dioxide.
Irritating smoke containing maleic anhydride may form in fire.

5.3 Advice for firefighters
Wear self-contained breathing apparatus (SCBA) and full protective clothing.
Fight fire from upwind. Cool containers with water spray until fire is extinguished.
Flash point: 127 °C

6.1 Personal precautions, protective equipment and emergency procedures
Wear appropriate personal protective equipment (see Section 8).
Avoid breathing dust/vapor. Ensure adequate ventilation.
Evacuate personnel to safe areas. Keep people away from and upwind of spill.

6.2 Environmental precautions
Prevent product from entering drains, waterways, or soil.
Contain spill with inert absorbent material.

6.3 Methods and materials for containment and cleaning up
Excerpt from ERG Guide 156 [Substances - Toxic and/or Corrosive (Combustible / Water-Sensitive)]:
IMMEDIATE PRECAUTIONARY MEASURE: Isolate spill or leak area in all directions for at least 50 meters (150 feet) for liquids and at least 25 meters (75 feet) for solids.
SPILL: Increase the immediate precautionary measure distance, in the downwind direction, as necessary.
FIRE: If tank, rail tank car or highway tank is involved in a fire, ISOLATE for 800 meters (1/2 mile) in all directions; also, consider initial evacuation for 800 meters (1/2 mile) in all directions. (ERG, 2024)
Personal protection: particulate filter respirator adapted to the airborne concentration of the substance. Do NOT let this chemical enter the environment. Sweep spilled substance into covered containers. If appropriate, moisten first to prevent dusting. Wash away remainder with plenty of water.
Pick up and arrange disposal without creating dust. Sweep up and shovel. Keep in suitable, closed containers for disposal.
Prevent further leakage or spillage if safe to do so. Do not let product enter drains. Discharge into the environment must be avoided.
ACCIDENTAL RELEASE MEASURES /Personal precautions, protective equipment and emergency procedures/ Use personal protective equipment. Avoid dust formation. Avoid breathing vapours, mist or gas. Ensure adequate ventilation. Evacuate personnel to safe areas. Avoid breathing dust.
SRP: Recycle any unused portion of the material for its approved use or return it to the manufacturer or supplier. Ultimate disposal of the chemical must consider: the material's impact on air quality; potential migration in air, soil or water; effects on animal, aquatic and plant life; and conformance with environmental and public health regulations. If it is possible or reasonable use an alternative chemical product with less inherent propensity for occupational harm/injury/toxicity or environmental contamination.
/Product/ Offer surplus and non-recyclable solutions to a licensed disposal company. /Contaminated packaging/ Dispose of as unused product.
SRP: The scientific literature for the use of contact lenses by industrial workers is inconsistent. The benefits or detrimental effects of wearing contact lenses depend not only upon the substance, but also on factors including the form of the substance, characteristics and duration of the exposure, the uses of other eye protection equipment, and the hygiene of the lenses. However, there may be individual substances whose irritating or corrosive properties are such that the wearing of contact lenses would be harmful to the eye. In those specific cases, contact lenses should not be worn. In any event, the usual eye protection equipment should be worn even when contact lenses are in place.
SRP: Local exhaust ventilation should be applied wherever there is an incidence of point source emissions or dispersion of regulated contaminants in the work area. Ventilation control of the contaminant as close to its point of generation is both the most economical and safest method to minimize personnel exposure to airborne contaminants. Ensure that the local ventilation moves the contaminant away from the worker.
Local exhaust.
Further processing of solid materials may result in the formation of combustible dusts. The potential for combustible dust formation should be taken into consideration before additional processing occurs. Avoid contact with skin and eyes. Avoid formation of dust and aerosols. Provide appropriate exhaust ventilation at places where dust is formed.
For more Preventive Measures (Complete) data for MALEIC ACID (6 total), please visit the HSDB record page.

7.1 Precautions for safe handling
Excerpt from ERG Guide 156 [Substances - Toxic and/or Corrosive (Combustible / Water-Sensitive)]:
ELIMINATE all ignition sources (no smoking, flares, sparks or flames) from immediate area. All equipment used when handling the product must be grounded. Do not touch damaged containers or spilled material unless wearing appropriate protective clothing. Stop leak if you can do it without risk. A vapor-suppressing foam may be used to reduce vapors. FOR CHLOROSILANES, use alcohol-resistant foam to reduce vapors. DO NOT GET WATER on spilled substance or inside containers. Use water spray to reduce vapors or divert vapor cloud drift. Avoid allowing water runoff to contact spilled material. Prevent entry into waterways, sewers, basements or confined areas.
SMALL SPILL: Cover with DRY earth, DRY sand or other non-combustible material followed with plastic sheet to minimize spreading or contact with rain. Use clean, non-sparking tools to collect material and place it into loosely covered plastic containers for later disposal. (ERG, 2024)
Provision to contain effluent from fire extinguishing. Separated from food and feedstuffs. Dry. Store only in original packaging.
Keep container tightly closed in a dry and well-ventilated place. Keep in a dry place. Storage class (TRGS 510): Non Combustible Solids
Storage temp: ambient

7.2 Conditions for safe storage, including any incompatibilities
Provision to contain effluent from fire extinguishing. Separated from food and feedstuffs. Dry. Store only in original packaging.
Keep container tightly closed in a dry and well-ventilated place. Keep in a dry place. Storage class (TRGS 510): Non Combustible Solids
Storage temp: ambient
Store away from incompatible materials (see Section 10).
[Note: Specific storage temperature not available in public databases. Refer to supplier Certificate of Analysis (COA) for exact storage conditions.]

8.1 Exposure controls
8.1.1 Occupational exposure limits (OEL)
OSHA PEL: Not established.
ACGIH TLV: Not established.
NIOSH REL: Not established.
No occupational exposure limit values are established for this substance.
Use the lowest feasible exposure level (ALARA principle).

8.1.2 Appropriate engineering controls
Use only in a chemical fume hood or with local exhaust ventilation.
Ensure adequate ventilation to keep airborne concentrations below exposure limits.

8.2 Individual protection measures
8.2.1 Eye/face protection
Wear chemical safety goggles and face shield.
8.2.2 Skin protection
Wear protective gloves. Recommended material: Nitrile rubber.
Wear suitable protective clothing (lab coat).
8.2.3 Respiratory protection
Use NIOSH-approved dust/mist respirator (N95 or higher) if ventilation is inadequate.
8.2.4 Thermal hazards
Not applicable.

9.1 Information on basic physical and chemical properties
a) Appearance: Maleic acid is a colorless crystalline solid having a faint odor. It is combustible though it may take some effort to ignite. It is soluble in water. It is used to make other chemicals and for dyeing and finishing naturally occurring fibers.
b) Odor: Faint acidulous odor
c) Odor threshold: No data available
d) pH: No data available
e) Melting point/freezing point: 266 to 268 °F (NTP, 1992)
f) Initial boiling point and boiling range: 275 °F at 760 mmHg (decomposes) (NTP, 1992)
g) Flash point: 127 °C
h) Evaporation rate: No data available
i) Flammability (solid, gas): No data available
j) Upper/lower flammability or explosive limits: No data available
k) Vapor pressure: Negligible (NTP, 1992)
l) Vapor density: No data available
m) Relative density: 1.59 at 68 °F (USCG, 1999) - Denser than water; will sink
n) Water solubility: greater than or equal to 100 mg/mL at 66 °F (NTP, 1992)
o) Partition coefficient: n-octanol/water: Log P: No data available
p) Auto-ignition temperature: No data available
q) Decomposition temperature: No data available
r) Viscosity: No data available
s) Explosive properties: No data available
t) Oxidizing properties: No data available

9.2 Other information

10.1 Reactivity
No specific reactivity hazards identified under normal handling conditions.

10.2 Chemical stability
Stable under recommended storage conditions.

10.3 Possibility of hazardous reactions
No hazardous reactions under normal conditions.

10.4 Conditions to avoid
Avoid heat, sparks, open flames, direct sunlight, and moisture.

10.5 Incompatible materials
Oxidizing agents

10.6 Hazardous decomposition products
No data available.
See also Section 5 (Fire-fighting measures) for combustion products.

11.1 Information on toxicological effects
Acute toxicity:
No acute toxicity data available.
Skin corrosion/irritation:
Causes skin irritation (H315).
Serious eye damage/eye irritation:
Causes serious eye damage (H318).
Respiratory or skin sensitization:
May cause an allergic skin reaction (H317).
Germ cell mutagenicity:
No data available.
Carcinogenicity:
No data available.
Reproductive toxicity:
No data available.
Specific target organ toxicity (single exposure):
H370
Specific target organ toxicity (repeated exposure):
No data available.
Aspiration hazard:
No data available.

11.2 Additional information
Carcinogen classification:
No indication of carcinogenicity to humans (not listed by IARC).
Exposure routes:
The substance can be absorbed into the body by inhalation and by ingestion.
Signs and symptoms of exposure:
Cough. Laboured breathing.
Redness. Pain.
Redness. Pain. Blurred vision.
Burning sensation. Further see Inhalation.
Data source: Hazardous Substances Data Bank (HSDB) via PubChem.

12.1 Toxicity
TLm Mosquito fish 240 ppm/24-48 hr fresh water /Conditions of bioassay not specified/
TLm Fathead minnow 5 ppm/96 hr fresh water /Conditions of bioassay not specified/
The substance is toxic to aquatic organisms.
Maleic acid's production and use in organic synthesis (to produce a variety of acids), in the dyeing and finishing of cotton, wool and silk, as a preservative for oils and fats, in the manufacture of artificial resins and in the preparation of maleate salts of drugs may result in its release to the environment through various waste streams. Maleic acid is released directly to the environment in motor vehicle exhaust and as a component of tobacco smoke. Maleic acid is reported to occur in ginseng, tobacco leaf, sour cherry fruit, cacao plant and corn plant. Maleic acid has been identified as a photooxidation product of biogenic compounds occurring in the ambient atmosphere such as d-limonene. If released to air, a vapor pressure of 1.34X10-5 mm Hg at 25 °C indicates maleic acid will exist in both the vapor and particulate phases in the atmosphere. Vapor-phase maleic acid will be degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals; the half-life for this reaction in air is estimated to be 2 days. Vapor-phase maleic acid will also be degraded in the atmosphere by reaction with ozone; the half-life for this reaction in air is estimated to be 13 days. Maleic acid has been detected in numerous atmospheric aerosol samples. Particulate-phas

12.2 Persistence and degradability
No data available.

12.3 Bioaccumulative potential
No data available.

12.4 Mobility in soil
No data available.

12.5 Results of PBT and vPvB assessment
PBT/vPvB assessment not available.

12.6 Other adverse effects
This substance is classified as hazardous to the aquatic environment.

13.1 Waste treatment methods
Waste Treatment Methods: Waste material must be disposed of in accordance with national and local regulations. Leave chemicals in original containers and do not mix with other waste. Handle uncleaned containers in the same manner as the product itself.

14.1 UN number
Not regulated as dangerous goods (research quantities typically exempt).

14.2 UN proper shipping name
Not subject to transport regulations (small quantities for research use).

14.3 Transport hazard class(es)
Class 8
DOT label: Corrosive

14.4 Packing group
Packing group III

14.5 Environmental hazards
Marine pollutant: No (not classified as environmentally hazardous per GHS).

14.6 Special precautions for user
Transport in original packaging. Ensure containers are tightly sealed.
For bulk or commercial quantities, consult applicable transport regulations (DOT, IATA, IMDG).

14.7 Transport in bulk according to Annex II of MARPOL 73/78 and the IBC Code
Not applicable.

15.1 Safety, health and environmental regulations/legislation specific for the substance or mixture
US EPA / TSCA: Subject to EPA TSCA regulations
EU ECHA / REACH: Registered (REACH Active)

SARA 302 Components:
No chemicals in this material are subject to the reporting requirements of SARA Title III, Section 302.
SARA 313 Components:
This material does not contain any chemical components with known CAS numbers that exceed the threshold (De Minimis) reporting levels established by SARA Title III, Section 313.
SARA 311/312 Hazards:
Acute (short-term) health hazard
Environmental hazard

Massachusetts Right To Know Components:
This material contains components subject to the Massachusetts Right to Know Act. See Section 2 for hazard classification.
Pennsylvania Right To Know Components:
This material contains components subject to the Pennsylvania Right to Know Act. See Section 2 for hazard classification.
New Jersey Right To Know Components:
This material contains components subject to the New Jersey Right to Know Act. See Section 2 for hazard classification.

California Prop. 65 Components:
This product does not contain any chemicals known to the State of California to cause cancer, birth defects, or any other reproductive harm.

Other regulatory listings:
- The Australian Inventory of Industrial Chemicals: Chemical: 2-Butenedioic acid, (Z)-
- New Jersey Worker and Community Right to Know Act: The New Jersey Worker and Community Right to Know Act requires public and private employers to provide information about hazardous substances at their workplaces. (N.J.S.A. 34:5A-1 et. seq.)
- Atmospheric Standards: This action promulgates standards of performance for equipment leaks of Volatile Organic Compounds (VOC) in the Synthetic Organic Chemical Manufacturing Industry (SOCMI). The intended effect of these standards is to require all newly constructed, modified, and reconstructed SOCMI process units to us
- Clean Water Act Requirements: Maleic acid is designated as a hazardous substance under section 311(b)(2)(A) of the Federal Water Pollution Control Act and further regulated by the Clean Water Act Amendments of 1977 and 1978. These regulations apply to discharges of this substance. This designation includes any isomers and hydrat
- CERCLA Reportable Quantities: Persons in charge of vessels or facilities are required to notify the National Response Center (NRC) immediately, when there is a release of this designated hazardous substance, in an amount equal to or greater than its reportable quantity of 5000 lb or 2270 kg. The toll free number of the NRC is (8

15.2 Chemical safety assessment
A chemical safety assessment has not been carried out for this substance.
For research-use-only compounds, no CSA is required under REACH Annex I.

Revision Date: 2026/09/09
Further Information: The information provided is believed to be correct but is not exhaustive and should be used only as a guideline based on current knowledge. It does not represent a guarantee of the properties of the product. Selleck Chemicals Corporation and its Affiliates shall not be held liable for any damage resulting from handling or contact with the product.

Note: Technical data last updated: Sep 1, 2026.