The Boston submarket with near-zero office and lab vacancies still has a sweet spot for manufacturing.

Tootsie Roll Industries is proposing a 10K SF addition to its 146K SF plant on Main Street between Kendall and Central Squares. While the factory does not produce Tootsie Rolls, it is responsible for Charleston Chews, Sugar Babies and the world’s entire supply of Junior Mints, the Boston Globe reports. The expansion is needed to replace older electrical equipment, according to plans Tootsie Roll subsidiary Cambridge Brands Inc. filed with the city of Cambridge.

The Tootsie Roll expansion is unique, as East Cambridge has notably shed its prior reputation as a hub for candy making in favor of becoming the world’s center for life science.

The factory for Squirrel Brand, maker of the Squirrel Nut Zippers candy, is now an affordable housing development. The factory where Necco wafers were made is now a lab for Novartis.

While Tootsie Roll may be the lone holdout, its expansion plans also include the addition of a mural to its employee parking lot to document the history of candy making in Cambridge.