UN Number: 2531 - CAS Number: 79-41-4

Also known as: ACIDE METHACRYLIQUE stabilisé, 2-Methacrylic Acid, 2-Methyl-2-Propenoic Acid, Methacrylic Acid, Acide Methacrylique
Information on chemical

Information on chemical

External resources

CAMEO Chemical Database
WISER Substance List


UN number 2531
CAS number 79-41-4
Formula C4H6O2

Physical chemical data

Physical State (20°C) Liquid
Physical State (25°C) Solid
Density (kg/m3)
1010 [Kg/m³] at a temperature of 20°C
Kinematic viscosity (cSt)
1.28 [cSt] at a temperature of 20°C
Molar mass (g/mol) 86.1
Density of gas (kg/m3) 3.87
Solubility (g/L)
89000 [g/L] at a temperature of 20°C and salinity of 0‰
89000 [g/L] at a temperature of 25°C and salinity of 0‰
Boiling Point (°C) 161
Melting Point (°C) 15
Surface tension (mN/m)
65.9 [mN/m] at a temperature of 20°C
Vapour Pressure (Pa)
90 [Pa] at a temperature of 20°C
133 [Pa] at a temperature of 25°C
Ignition Temperature (°C) 400
Flash Point (°C) 77
Flash Point (Cleveland open cup) (°C) 77
Lower explosivity limit (LEL) (volume %) 2.4
Upper explosivity limit (UEL) (volume %) 8.8
Specific heat capacity (J/(Kg·K)) 1871
Henry's constant (mol/(m³·Pa)) 0.039

Behaviour at sea

Log kow 0.93
Log koc 0.35
Aqueous photolysis (Half-life) Not photolysable
Biodegradation in estuary environment (Half-life) (days) Not hydrolysable
Bioconcentration factor (BCF) 3.1

Additional data

Colour colourless
Odour sharp, acrid, repulsive
MARPOL pollution category
Category Description
Y Noxious Liquid Substances which, if discharged into the sea from tank cleaning or deballasting operations, are deemed to present a hazard to either marine resources or human health or cause harm to amenities or other legitimate uses of the sea and therefore justify a limitation on the quality and quantity of the discharge into the marine environment.

Transportation data

Transport mode Bulk,Packaged
Package group III
Temperature (°C) ambient
Family name organic acids

Reactivity data

Water No
Acid(s) Yes
Base(s) Yes
Oxidizing agents Yes
Organic substance Yes

GESAMP Hazard profile

Bioaccumulation in logPow (A1A) 0 - e <1, or > ca.7, or Mol. Wt. > 1000
Bioaccumulation (A1) 0 - No potential to bioaccumulate
Biodegradation (A2) R - Readily biodegradable
Acute aquatic toxicity (B1) (LC/EC/IC50 (mg/l)) 2 - Slightly toxic
Chronic aquatic toxicity (B2) (NOEC (mg/l)) 0 - Negligible
Acute mammalian toxicity by swallowing (C1) (LD50 (mg/kg)) 1 - Slight
Acute mammalian toxicity by skin penetration (C2) (LD50 (mg/kg)) 2 - Moderate
Acute mammalian toxicity by inhalation (C3) (LC50 (mg/l)) 2 - Moderate
Skin irritation/corrosivity (D1) 1 - Mildly irritating
Eye irritation/corrosivity (D2) 3 - Severely irritating, with irreversible corneal injury
Interference with coastal amenities (E2) D - Dissolver
Effects on wildlife and bottom habitats (E3) 3 - Is highly acutely toxic; and/or is severely irritant or corrosive to skin or eyes; and/or is carcinogenic, mutagenic or reprotoxic; and/or is a floater or persistent floater with associated health effects

Human toxicity threshold

Corrosive Toxic
Hazard statements
H302 Harmful if swallowed.
H311 Toxic in contact with skin.
H314 Causes severe skin burns and eye damage.
H332 Harmful if inhaled.
H335 May cause respiratory irritation.
Precautionary statements
P280 Wear protective gloves/protective clothing/eye protection/face protection.
P303 + P361 + P353 IF ON SKIN (or hair): Remove/Take off immediately all contaminated clothing. Rinse skin with water/shower.
P305 + P351 + P338 IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing.
P405 Store locked up.
P501 Dispose of contents/container to ...
TEEL-1 (mg/m3) 6.7 ppm
TEEL-2 (mg/m3) 61 ppm
TEEL-3 (mg/m3) 220 ppm


Lowest median lethal concentration (LC50) on algae (mg/l) 45
Lowest median lethal concentration (LC50) on crustacean (mg/l) 140
Lowest median lethal concentration (LC50) on fishes (mg/l) 85
Highest no observed effect concentration (NOEC) on algae (mg/l) 8.2
Highest no observed effect concentration (NOEC) on crustacean (mg/l) 53
Highest no observed effect concentration (NOEC) on fishes (mg/l) 10
Assessment factor (AF)
50 on the Short term
Predicted No Effect Concentration (PNEC) (µg/l)
164 [µg/l] on the Short term
Incident reports

Incident reports

No incident reports available

Emergency Response Guidebook

Emergency Response Guidebook

Guide number: 153P

See the guide or download the emergency response guidebook

At sea emergency guide

At sea emergency guide

No guides available

Decision trees

Decision trees

No decision trees available

No additional data

last modified 2023-03-06T11:34:29+00:00

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