Melting point :130-135 °C (lit.)
Boiling point :275°C
Density :1.59 g/mL at 25 °C (lit.)
bulk density :750-800kg/m3
vapor pressure :0.001Pa at 20℃
refractive index :1.5260 (estimate)
Flash point :127 °C
storage temp. :Store below +30°C.
solubility :478.8g/l
pka :1.83(at 25℃)
form :Powder/Solid
Specific Gravity :1.59
color :White
PH :3.05(1 mM solution);2.21(10 mM solution);1.54(100 mM solution);
Odor :Faint odor
Water Solubility :790 g/L (25 ºC)
Merck :14,5703
BRN :605762
Henry's Law Constant :1.4×10⁸ mol/(m³Pa) at 25℃, Lide and Frederikse (1995)
Stability :Stable. Combustible. Incompatible with strong oxidizing agents, bases.
Cosmetics Ingredients Functions :BUFFERING
Cosmetic Ingredient Review (CIR) :Maleic acid (110-16-7)
InChI :1S/C4H4O4/c5-3(6)1-2-4(7)8/h1-2H,(H,5,6)(H,7,8)/b2-1-
InChIKey :VZCYOOQTPOCHFL-OWOJBTEDSA-N
SMILES :OC(=O)\C=C/C(O)=O
LogP :-1.3 at 20℃
CAS DataBase Reference :110-16-7(CAS DataBase Reference)
NIST Chemistry Reference :2-Butenedioic acid (Z)-(110-16-7)
EPA Substance Registry System :Maleic acid (110-16-7)

Symbol(GHS):
Signal word:	Danger
Hazard statements:	Code Hazard statements Hazard class Category Signal word Pictogram P-Codes H315 Causes skin irritation Skin corrosion/irritation Category 2 Warning P264, P280, P302+P352, P321,P332+P313, P362 H317 May cause an allergic skin reaction Sensitisation, Skin Category 1 Warning P261, P272, P280, P302+P352,P333+P313, P321, P363, P501 H318 Causes serious eye damage Serious eye damage/eye irritation Category 1 Danger P280, P305+P351+P338, P310 H335 May cause respiratory irritation Specific target organ toxicity, single exposure;Respiratory tract irritation Category 3 Warning
Precautionary statements:	P261 Avoid breathing dust/fume/gas/mist/vapours/spray. P264 Wash hands thoroughly after handling. P264 Wash skin thouroughly after handling. P280 Wear protective gloves/protective clothing/eye protection/face protection. P301+P312 IF SWALLOWED: call a POISON CENTER or doctor/physician IF you feel unwell. P305+P351+P338 IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continuerinsing.