MF: C₁₂H₆C_l4
MW: 291.988040 g/mol 
Density: 1.441 g/cm³ 
Flash Point: 190 °C 
Index of Refraction: 1.612
Enthalpy of Vaporization: 60.67 kJ/mol
Boiling Point: 382.9 °C at 760 mmHg
Air & Water Reactions: Insoluble in water
General Description: Viscous oily liquid.  
Vapour Pressure: 1.01E-05 mmHg at 25°C 
IUPAC Name: 1,3-Dichloro-5-(3,5-dichlorophenyl)benzene
Synonyms: [40cfr136(1986)]Pcb-1248 ; aroclor1248referencestandardforclp ; Chlorodiphenyl(48%cl) ; Kanechlor400 ; Polychlorinatedbiphenyl(aroclor1248) ; Aroclor 1248, 1X1ML, ISO, 1UG/ML ; Aroclor 1248, 1X1ML, ISO, 1000UG/ML ; Aroclor 1248, 1X5ML, Transformer OIL 500 MG/KG
Following is the molecular structure of  Polychlorinatedbiphenyl(aroclor1248) (12672-29-6):

Consensus of  Polychlorinatedbiphenyl(aroclor1248) (12672-29-6):
IARC Cancer Review: Human Limited Evidence IMEMDT    IARC Monographs on the Evaluation of Carcinogenic Risk of Chemicals to Man . 18 ,1978,p. 43.(World Health Organization, Internation Agency for Research on Cancer,Lyon, France.: ) (Single copies can be ordered from WHO Publications Centre U.S.A., 49 Sheridan Avenue, Albany, NY 12210) .

Suspected human carcinogen. Moderately toxic by skin contact. Experimental teratogenic and reproductive effects. When heated to decomposition it emits toxic fumes of Cl⁻. Used in heat transfer, hydraulic fluids, lubricants, and insecticides.
Safety Information of of  Polychlorinatedbiphenyl(aroclor1248) (12672-29-6):
Hazard Codes: Xi,N,T,F,Xn
Xi: Irritant N: Dangerous for the environment
Xn: Harmful  T: ToxicF: Highly Flammable
Risk Statements  36/37/38-50/53-33-39/23/24/25-23/24/25-11-67-65-38-62-51/53-48/20
36/37/38:  Irritating to eyes, respiratory system and skin 
50/53:  Very Toxic to aquatic organisms, may cause long-term adverse effects in the aquatic environment 
33:  Danger of cumulative effects 
39/23/24/25:  Toxic: danger of very serious irreversible effects through inhalation, in contact with skin and if swallowed 
23/24/25: Toxic by inhalation, in contact with skin and if swallowed 
11: Highly Flammable 
67: Vapors may cause drowsiness and dizziness 
65: Harmful: May cause lung damage if swallowed 
38: Irritating to the skin 
62: Possible risk of impaired fertility 
51/53: Toxic to aquatic organisms, may cause long-term adverse effects in the aquatic environment 
48/20: Harmful: danger of serious damage to health by prolonged exposure through inhalation 
Safety Statements: 26-61-60-35-45-36/37-16-7-62-33-29-9-36
26: In case of contact with eyes, rinse immediately with plenty of water and seek medical advice 
61: Avoid release to the environment. Refer to special instructions safety data sheet 
60: This material and/or its container must be disposed of as hazardous waste 
35: This material and its container must be disposed of in a safe way 
45: In case of accident or if you feel unwell, seek medical advice immediately (show label where possible) 
36/37: Wear suitable protective clothing and gloves 
16: Keep away from sources of ignition - No smoking 
7: Keep container tightly closed 
62: If swallowed, do not induce vomiting: seek medical advice immediately and show this container or label 
33: Take precautionary measures against static discharges 
29: Do not empty into drains 
9: Keep container in a well-ventilated place 
36: Wear suitable protective clothing 
RIDADR: 2315
RTECS: TQ1358000
HazardClass: 9
PackingGroup: II

NIOSH REL: TWA (Polychlorinated Biphenyls) 0.001 mg/m³