Environmental Effects
Hexachlorobenzene tends to remain in the environment for a long time. If it is released to the soil, it has a half-life of 3-6 years. This means that half of the total amount will disappear after 3-6 years, half of the remaining amount will disappear in another 3-6 years, and this process will continue each 3-6 years thereafter. If it is released to surface waters such as lakes, rivers, and streams, the half-life is 2.7-5.7 years, and if it is released to groundwater, the half-life is 5.3-11.4 years. Since hexachlorobenzene does not dissolve in water very well, most of it will remain in particles on the bottom of lakes, rivers, or streams. The evaporation of hexachlorobenzene into the air is not significant under ordinary conditions. Once in the air, it can be carried over wide geographic areas. Its half-life in air ranges from 0.63 to 6.28 years (#ATSDR-Public Health Statement for Hexachlorobenzene).
Hexachlorobenzene is a highly persistent compound and it is slightly or moderately toxic to birds, fish, and nontoxic to bees (#EXTOXNET).