Epichlorohydrin (1-chloro-2,3-epoxypropane) is specifically named at subheading 291030 because of its commercial importance as an epoxy resin precursor. Other halogenated or otherwise derivatized epoxides that are not individually named fall under the residual subheading 291090.

Both dieldrin (291040) and endrin (291050) are persistent organic pollutants listed under the Stockholm Convention and are banned or severely restricted in most countries. Any import would require EPA review and documentation demonstrating a permitted use; in practice, commercial trade in these compounds is extremely limited.