Fact sheet: 1,2,4,5-tetrachlorobenzene

From: Public Services and Procurement Canada

Discover a list of a contaminant's important chemical properties, how it will react in the environment, main sources of contamination related, and a brief overview of health and safety issues.

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General information

CAS number


Molecular formula


Formula weight

215.9 g/mol



Properties (at room temperature where applicable)

Compound properties list
Melting/boiling point139 °CSolid
Relative density1.86 g/cm3Sinks in water
Vapour pressure0.005 mm HgVery low volatility
Vapour density0N/A
Solubility in water0.5 mg/LVery low solubility
Henry's law constant1 x 10-3atm·m3/molModerately volatile when dissolved
log Koc (Depending on soil or sediment characteristics)2.8 - 6.0*Strong adsorption to organic matter

Environmental behaviour

At 20 0C, 1,2,4,5-tetrachlorobenzene is a solid with very low volatility and solubility. Once dissolved, it is moderately volatile and adsorbs strongly to organic matter. When present in the soil, it volatilizes and dissolves very slowly. In the dissolved phase, 1,2,4,5-tetrachlorobenzene can reach the water table or drain into a waterway where it will be diluted before partially volatilizing. Fragments of 1,2,4,5-tetrachlorobenzene can also be carried into a waterway and deposited at the bottom where they will dissolve very slowly. Once the source has been removed, the adsorbed phase will take a long time to disappear, liberating contamination in either the gaseous or dissolved state.. The resulting plumes (gaseous and dissolved) are generally small in size.

Health and safety

In Canada, 1,2,4,5-tetrachlorobenzene is considered "toxic", as defined under Paragraph 64(a) of CEPA 1999, and has been added to Schedule 1.

Principal resources

1,2,4,5-tetrachlorobenzene is not currently produced or used in its pure form in Canada nor is there any current domestic commercial demand for 1,2,4,5-tetrachlorobenzene. Formerly, it could be found in dielectric fluids where it was used to top up polychlorinated biphenyl (PCB) transformers and in dyestuff carriers. These applications have either been discontinued (dye carriers) or are being phased out (dielectric fluids). A possible source of release may include dielectric PCB material still in use. 1,2,4,5-tetrachlorobenzene may be generated when organic compounds are burned or exposed to a large source of energy in the presence of a chlorine source.

Other possible uses include insecticides, intermediates in herbicide and defoliant production, and as an additive for moisture resistance.


Environment Canada. 2009. CEPA Environmental Registry: Toxic Substances List-Updated Schedule 1 as of December 27, 2006. Environment Canada. (Viewed December 2013)

Environment Canada. 2009. Management of Toxic Substances: Tetrachlorobenzenes (TeCBs). Environment Canada. (Viewed December 2013)

Montgomery, John H. 2007. Groundwater Chemicals, Desk Reference, Fourth Edition, CRC Press, Taylor and Francis Group, Florida, U.S.A.