Why did the EPA classify creosote, penta, and inorganic arsenicals as restricted-use?

The classification of creosote, penta (pentachlorophenol), and inorganic arsenicals as restricted-use by the EPA is primarily due to the potential human health hazards associated with these substances. These chemicals are known to pose significant risks, such as carcinogenic effects and other severe health impacts upon exposure. As a result, their use is closely regulated to minimize the risk of harmful effects on individuals who may come into contact with them, as well as to protect public health overall.

While cost, environmental impact, and effectiveness may also contribute to considerations around the use of certain chemicals, they are not the primary reasons behind the restricted-use classification for these particular compounds. The focus on human health hazards indicates a careful assessment of how these chemicals could adversely affect those who use them or are exposed to treated materials.