Empirical Formula: C₁₂H₁₃ClN₂
Molecular Weight: 220.698
Nominal Mass: 220 Da
Average Mass: 220.698 Da
Monoisotopic Mass: 220.076726 Da 
EINECS: 218-599-4 
Flash Point: 197.8 °C
Enthalpy of Vaporization: 59.97 kJ/mol
Boiling Point: 354.7 °C at 760 mmHg
Vapour Pressure: 3.29E-05 mmHg at 25 °C
Appearance: Grey-bluish powder
Structure of p-Phenylenediamine, N-phenyl-, hydrochloride (CAS NO.2198-59-6):
                        
IUPAC Name: 1-N-Phenylbenzene-1,4-diamine hydrochloride
Canonical SMILES: C1=CC=C(C=C1)NC2=CC=C(C=C2)N.Cl
InChI: InChI=1S/C12H12N2.ClH/c13-10-6-8-12(9-7-10)14-11-4-2-1-3-5-11;/h1-9,14H,13H2;1H
InChIKey: PNEVDCGZQWFIKV-UHFFFAOYSA-N
Product Category of p-Phenylenediamine, N-phenyl-, hydrochloride (CAS NO.2198-59-6): Intermediates of Dyes and Pigments

 p-Phenylenediamine, N-phenyl-, hydrochloride (CAS NO.2198-59-6) hasn't been listed as a carcinogen by NTP, IARC, ACGIH, or CA Prop 65. You can see actual entry in RTECS for complete information.

Risk Statements: 36/37/38
R36/37/38:Irritating to eyes, respiratory system and skin.
Safety Statements" 26-36/37/39 
S26: In case of contact with eyes, rinse immediately with plenty of water and seek medical advice. 
S36/37/39:Wear suitable protective clothing, gloves and eye/face protection.

 p-Phenylenediamine, N-phenyl-, hydrochloride , its cas register number is 101-54-2. It also can be called 1,4-Benzenediamine, N-phenyl-, hydrochloride ; 4-Aminodiphenylamine hydrochloride ; N-Phenyl-1,4-benzenediamine hydrochloride ; and p-Aminodiphenylamine hydrochloride . It is hazardous, so the first aid measures and others should be known. Such as: When on the skin: first, should flush skin with plenty of water immediately for at least 15 minutes while removing contaminated clothing. Secondly, get medical aid. Or in the eyes: Flush eyes with plenty of water for at least 15 minutes, occasionally lifting the upper and lower eyelids. Then get medical aid soon. While, it's inhaled: Remove from exposure and move to fresh air immediately. Give artificial respiration while not breathing. When breathing is difficult, give oxygen. And as soon as to get medical aid. Then you have the ingesting of the product: If victim is conscious and alert, give 2-4 cupfuls of milk or water. Get medical aid immediately. Notes to physician: Treat supportively and symptomatically.
In addition, p-Phenylenediamine, N-phenyl-, hydrochloride (CAS NO.2198-59-6) could be stable under normal temperatures and pressures. You must not take it with Strong oxidants. And also prevent it to broken down into hazardous decomposition products: irritating and toxic fumes and gases.