Tarslag

Tarslag is a term used in Swedish-language sources to describe a solid byproduct produced during tar production from wood or coal. Historically, it refers to the dense, hard residue left after tar distillation, which could be collected for use as a waterproofing and sealing material or disposed of as waste.

Production and composition: Tarslag forms during the distillation of tar from wood or coal. It is typically a dense mixture of pitch and bitumen, with variable amounts of mineral matter and condensates from the tar. The exact composition depends on the raw material and processing methods.

Uses and history: In earlier centuries tarslag was used for waterproofing roofs, boats, and wooden structures, and in some regions for sealing joints or road repairs. As technology advanced, it was largely replaced by more modern sealants and asphalt-based products, reducing its practical use in everyday construction.

Environmental and health aspects: Tar-derived materials may contain polycyclic aromatic hydrocarbons and other hazardous substances. Handling, dust generation, and disposal can pose health and environmental risks, leading to regulatory controls and the preference for safer substitutes. Remediation of sites containing tar residues typically involves containment or cleanup measures consistent with hazardous-waste practices.

See also: coal tar, pine tar, bitumen, asphalt, tar, slag.