IUPAC Name: 4-methyl-N-methyldiazenylaniline 
Synonyms of 3-Methyl-1-(p-tolyl)-triazene (CAS NO.21124-13-0): 1-Methyl-3-(4-methylphenyl)triazene ; 1-Methyl-3-p-tolyltriazene ; 1-Triazene, 1-methyl-3-(4-methylphenyl)- ; 3-Methyl-1-(4-methylphenyl)triazene ; 3-Methyl-1-(p-tolyl)-triazene ; EINECS 244-223-3 ; Methyl-p-tolyltriazene ; NSC 106329 ; Triazene, 3-methyl-1-(p-tolyl)-
CAS NO: 21124-13-0
Molecular Formula of 3-Methyl-1-(p-tolyl)-triazene (CAS NO.21124-13-0): C₈H₁₁N₃
Molecular Weight: 149.193
Molecular Structure:

H bond acceptors: 3
H bond donors: 1
Freely Rotating Bonds: 1
Polar Surface Area: 27.96 Å²
Index of Refraction: 1.541
Molar Refractivity: 45.65 cm³
Molar Volume: 145 cm³
Surface Tension: 34.9 dyne/cm
Density of 3-Methyl-1-(p-tolyl)-triazene (CAS NO.21124-13-0): 1.02 g/cm³
Flash Point: 84.1 °C
Enthalpy of Vaporization: 45.18 kJ/mol
Boiling Point: 215.5 °C at 760 mmHg
Vapour Pressure: 0.147 mmHg at 25°C 
Melting point: 75-80 °C
storage temp.: Refrigerator

Reported in EPA TSCA Inventory.

Hazard Codes: Xn
Risk Statements: 20/21/22-40 
R20/21/22: Harmful by inhalation, in contact with skin and if swallowed. 
S40: To clean the floor and all objects contaminated by this material, use .... (there follows suitable cleaning material).
Safety Statements: 26-28-36/37/39-45 
S26: In case of contact with eyes, rinse immediately with plenty of water and seek medical advice. 
S28: After contact with skin, wash immediately with plenty of soap-suds. 
S36/37/39: Wear suitable protective clothing, gloves and eye/face protection. 
S45: In case of accident or if you feel unwell, seek medical advice immediately (show the label whenever possible.)
RIDADR: 1325
WGK Germany: 3
RTECS: XY2785500
HazardClass: 4.1
PackingGroup: III
Poison by ingestion. Mutation data reported. When heated to decomposition it emits toxic fumes of NO_x.