Used primarily as a biocide and preservative, especially in wood treatment to protect against fungal decay, termites, and other pests. It is effective in industrial settings for preserving utility poles, railroad ties, and structural timber. Also found application in antifouling paints for marine vessels to prevent growth of algae, barnacles, and other organisms on hulls. Has been used in some specialty chemical formulations as an intermediate in the synthesis of dyes, pigments, and other chlorinated compounds. Due to its persistence, toxicity, and potential to bioaccumulate, its use is highly restricted or banned in many countries under international agreements like the Stockholm Convention on Persistent Organic Pollutants.