CRT glass and other activated glass contain lead and other hazardous materials that give it a distinct regulatory and commercial profile; it is classified in the electronics chapter under heading 8549. This heading covers conventional soda-lime, borosilicate, and similar glass cullet and scrap intended for standard glass manufacturing.

Cullet refers to broken or crushed recycled glass collected for remelting. 'Glass in the mass' covers glass that has been melted and formed into a raw, unworked shape (such as frit or cast blocks) but has not yet been drawn, blown, rolled, or otherwise worked into a usable product. Both are pre-production feedstocks and both fall under the single subheading 700100.