Chemistry informtion about 2,3-Benzofluorene (CAS NO.243-17-4) is:
IUPAC Name: 11h-Benzo[B]Fluorene
Synonyms: 2,3-Benzofluorene ; 2,3-Benzfluorene ; 11h-Benzo[B]Fluorene ; Isonaphthofluorene ; Benz[B]Flurene ; Benzo(B)Fluorene ; Benzo(B)Fluorene Oekanal, 100 Mg ; 2,3-Benzofluorene, Tech., 90%
MF: C₁₇H₁₂
MW: 216.28
EINECS: 205-952-2 
Melting Point: 211-213 °C(lit.)
Density: 1.185 g/cm³
Flash Point: 185.4 °C
Boiling Point: 398.3 °C at 760 mmHg
Vapour Pressure: 3.43E-06 mmHg at 25°C
Enthalpy of Vaporization: 62.35 kJ/mol
Following is the molecular structure of 2,3-Benzofluorene (CAS NO.243-17-4) is:

IARC Cancer Review: Group 3 IMEMDT    IARC Monographs on the Evaluation of Carcinogenic Risk of Chemicals to Man . 7 (1987),p. 56.(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) ; Animal Inadequate Evidence IMEMDT    IARC Monographs on the Evaluation of Carcinogenic Risk of Chemicals to Man . 32 (1983),p. 183.(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) ; Human No Adequate Data IMEMDT    IARC Monographs on the Evaluation of Carcinogenic Risk of Chemicals to Man . 32 (1983),p. 183.(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) . Reported in EPA TSCA Inventory.

Mutation data reported. Questionable carcinogen. When heated to decomposition it emits acrid smoke and irritating vapors. 
Safety Statements:
S22:Do not breathe dust. 
S24/25:Avoid contact with skin and eyes.
RIDADR: 2811
WGK Germany: 3
RTECS: DF6383500
HazardClass: 6.1(b)
PackingGroup: III

2,3-Benzofluorene (CAS NO.243-17-4) is almost white to yellow-green crystalline powder.
First Aid Measures:
Eyes: Flush eyes with plenty of water for at least 15 minutes, occasionally lifting the upper and lower eyelids. Get medical aid immediately.
Skin: Get medical aid. Flush skin with plenty of water for at least 15 minutes while removing contaminated clothing and shoes. Remove contaminated clothing and shoes.
Ingestion: If victim is conscious and alert, give 2-4 cupfuls of milk or water. Get medical aid immediately.
Inhalation: Get medical aid immediately. Remove from exposure and move to fresh air immediately. If not breathing, give artificial respiration. If breathing is difficult, give oxygen. 
Handling and Storage:
Handling: Wash thoroughly after handling. Remove contaminated clothing and wash before reuse. Avoid contact with eyes, skin, and clothing. Avoid ingestion and inhalation.
Storage: Store in a cool, dry place. Keep container closed when not in use.