Reported in EPA TSCA Inventory.

OSHA PEL: TWA 50 ppm; STEL 75 ppm
ACGIH TLV: TWA 50 ppm; STEL 75 ppm

The o-Chlorostyrene, with the CAS registry number 2039-87-4 and EINECS registry number 218-026-8, has the systematic name of 1-chloro-2-ethenylbenzene. And the molecular formula of this chemical is C₈H₇Cl. It is a kind of clear colourless to light yellow liquid, and belongs to the following product categories:Styrenes; High Refractive Index MonomersPolymer Science; Monomers; Photonic and Optical Materials; Styrene and Functionalized Styrene Monomers; Waveguide Materials. What's more, it should be stored in the refrigerator.
 
The physical properties of o-Chlorostyrene are as following: (1)ACD/LogP: 3.55; (2)# of Rule of 5 Violations: 0; (3)ACD/LogD (pH 5.5): 3.554; (4)ACD/LogD (pH 7.4): 3.554; (5)ACD/BCF (pH 5.5): 296.046; (6)ACD/BCF (pH 7.4): 296.046; (7)ACD/KOC (pH 5.5): 2044.579; (8)ACD/KOC (pH 7.4): 2044.579; (9)#H bond acceptors: 0; (10)#H bond donors: 0; (11)#Freely Rotating Bonds: 1; (12)Polar Surface Area: 0 Å²; (13)Index of Refraction: 1.575; (14)Molar Refractivity: 42.072 cm³; (15)Molar Volume: 127.332 cm³; (16)Polarizability: 16.679×10^-24cm³; (17)Surface Tension: 34.282 dyne/cm; (18)Density: 1.088 g/cm³; (19)Flash Point: 60.443 °C; (20)Enthalpy of Vaporization: 40.816 kJ/mol; (21)Boiling Point: 189.382 °C at 760 mmHg; (22)Vapour Pressure: 0.79 mmHg at 25°C.

Uses of o-Chlorostyrene: It can react with 6-oxo-6H-pyran-3-carboxylic acid methyl ester to produce 2'-chloro-biphenyl-4-carboxylic acid methyl ester. This reaction will need catalyst 10% Pd/C, and the solvent m-xylene. The reaction time is 10 hours with temperature of 140°C, and the yield is about 82%.

You should be cautious while dealing with this chemical. It irritates eyes, respiratory system and skin, and it is also harmful by inhalation and if swallowed. What's more, it may cause cancer. Therefore, you had better take the following instructions: Wear suitable protective clothing, gloves and eye/face protection, and in case of contacting with eyes, rinse immediately with plenty of water and seek medical advice; Avoid exposure - obtain special instruction before use; Do not breathe gas/fumes/vapor/spray (appropriate wording to be specified by the manufacturer); In case of accident or if you feel unwell, seek medical advice immediately (show label where possible).

You can still convert the following datas into molecular structure:
(1)SMILES: C=Cc1ccccc1Cl
(2)InChI: InChI=1/C8H7Cl/c1-2-7-5-3-4-6-8(7)9/h2-6H,1H2
(3)InChIKey: ISRGONDNXBCDBM-UHFFFAOYAD

The toxicity data is as follows: