1,4-Dichlorobenzene

1,4-Dichlorobenzene
	1,4-dichlorobenzene crystallised on paper from DCM solution
Names
	Preferred IUPAC name 1,4-Dichlorobenzene
	Other names 1,4-DCB; para-Dichlorobenzene; p-Dichlorobenzene; p-DCB; PDCB; Paramoth; Para crystals; Paracide; Dichlorocide
Identifiers
CAS Number	106-46-7 ;
3D model (JSmol)	Interactive image;
Beilstein Reference	1680023
ChEBI	CHEBI:28618 ;
ChEMBL	ChEMBL190982 ;
ChemSpider	13866817 ;
ECHA InfoCard	100.003.092
EC Number	203-400-5;
Gmelin Reference	49722
KEGG	C07092 ;
PubChem CID	4685;
RTECS number	CZ4550000;
UNII	D149TYB5MK ;
UN number	3077
CompTox Dashboard (EPA)	DTXSID1020431 ;
	InChI InChI=1S/C6H4Cl2/c7-5-1-2-6(8)4-3-5/h1-4H Key: OCJBOOLMMGQPQU-UHFFFAOYSA-N ;
	SMILES ClC1=CC=C(Cl)C=C1;
Properties
Chemical formula	C6H4Cl2
Molar mass	147.00 g·mol−1
Appearance	Colorless/white crystals
Odor	mothball-like
Density	1.25 g/cm3, solid
Melting point	53.5 °C (128.3 °F; 326.6 K)
Boiling point	174 °C (345 °F; 447 K)
Solubility in water	10.5 mg/100 mL (20 °C)
Vapor pressure	1.3 mmHg (20 °C)
Magnetic susceptibility (χ)	−82.93·10−6 cm3/mol
Hazards
	Occupational safety and health (OHS/OSH):
Main hazards	Suspected carcinogen
	GHS labelling:
Pictograms
Signal word	Warning
Hazard statements	H302, H315, H317, H319, H332, H335, H351, H410
Precautionary statements	P201, P202, P261, P264, P270, P271, P272, P273, P280, P281, P301+P312, P302+P352, P304+P312, P304+P340, P305+P351+P338, P308+P313, P312, P321, P330, P332+P313, P333+P313, P337+P313, P362, P363, P391, P403+P233, P405, P501
NFPA 704 (fire diamond)	2 2 0
Flash point	66 °C (151 °F; 339 K)
Explosive limits	2.5%-?
	Lethal dose or concentration (LD, LC):
LD50 (median dose)	500 mg/kg (rat, oral); 2950 mg/kg (mouse, oral); 2512 mg/kg (rat, oral); 2830 mg/kg (rabbit, oral)
LDLo (lowest published)	857 mg/kg (human, oral); 4000 mg/kg (rat, oral); 2800 mg/kg (guinea pig, oral)
	NIOSH (US health exposure limits):
PEL (Permissible)	TWA 75 ppm (450 mg/m3)
REL (Recommended)	Ca
IDLH (Immediate danger)	Ca [150 ppm]
Related compounds
Related compounds	1,2-Dichlorobenzene; 1,3-Dichlorobenzene
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) Infobox references

1,4-Dichlorobenzene (1,4-DCB, p-DCB, or para-dichlorobenzene, sometimes abbreviated as PDCB or para) is an aryl chloride and isomer of dichlorobenzene with the formula C₆H₄Cl₂. This colorless solid has a strong odor. The molecule consists of a benzene ring with two chlorine atoms (replacing hydrogen atoms) on opposing sites of the ring.

It is used as a disinfectant, pesticide, and deodorant, most familiarly in mothballs in which it is a replacement for the more traditional naphthalene because of naphthalene's greater flammability (though both chemicals have the same NFPA 704 rating). It is also used as a precursor in the production of the chemically and thermally resistant polymer poly(p-phenylene sulfide).