Monobutyl ethers of mono- or di-ethylene glycols have their own subheading (290943), while other monoalkyl ethers of those glycols fall under 290944. Residual ether-alcohols and their halogenated or nitrated derivatives that do not fit the named subheadings are captured by 290949. The specific alkyl chain length and the glycol base determine the correct slot.

Organic peroxides can be classified as hazardous materials under DOT regulations, requiring proper hazmat labeling, packaging, and documentation regardless of their HTS classification. Importers should confirm whether the specific compound triggers DOT, OSHA, or EPA reporting thresholds before shipment.