Creosote is the common name used for a variety of products including wood creosote, coal tar creosote, coal tar, coal tar pitch, and coal tar pitch volatiles. These products are mixtures of many chemicals and are created by high-temperature treatment of beech and other woods, coal, or the resin of the creosote bush (chaparral).
Creosote is used as a wood preservative and it is also a restricted-use pesticide. Moreover, it can be found in medicines used to treat skin diseases such as psoriasis. Coal tar, coal tar pitch, and coal tar pitch volatiles are used in several industries, including road paving, roofing, aluminium smelting, and coking.
Creosote prepared from coal tar is the most common form of creosote in the workplace and at hazardous waste sites. It is a thick, oily liquid that is typically amber to black in col- our. It is easily set on fire and does not dissolve easily in water.
Why is creosote a hazardous substance?
Exposure to creosote can lead to various health problems in humans. On the one hand, short-term exposure to relatively high levels of it can cause the following symptoms: irritation of the eyes and skin, disorders of the central nervous system, kidney and liver damage, and skin damage.
On the other hand, skin cancer and cancer of the scrotum have resulted from long-term exposure to low levels of creosote products, especially through direct contact with the skin during wood treatment or manufacture of coal tar creosote-treated products, or in coke or natural gas factories.
However, since the composition of this substance can exhibit relatively great differences depending on the original material (type of coal) and the distillation process, the effects of the individual products must also be expected to trigger different effects.
Furthermore, there is no clear information available on what happens to wood creosote when it enters the environment. However, it contains some components that dissolve in water and some that do not. The ones that do dissolve in water may move through the soil to eventually reach and enter the groundwater, where they may persist. Once in the ground-water, breakdown may take years. Most of the components that are not water-soluble will remain in place in a tar-like mass. Migration from the site of contamination is not extensive. Breakdown in soil can take months for some components of coal tar creosote, and much longer for others.
Once coal tar creosote is in the environment, both plants and animals can absorb parts of the creosote mixture.
Where can it be found?
Creosote has been used and is still being used, as a wood preservative in many applications in construction.
Therefore, in demolition and dismantling it is very common to find wood treated with creosote in the following elements:
- Fences
- Bridges
- Railroad tracks
- Telephone poles
- Log homes
Moreover, it is present in wood preservative, coke-producing and asphalt industries.
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This article can be found in the 2022 edition of the document. Find the full publication here:
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