Photography by Hope Chang

At two of Yale’s residential colleges, an innovative machine is harnessing basic chemistry to achieve a new kind of green cleaning.

Since 2022, the custodial team at Benjamin Franklin and Pauli Murray colleges has been using a machine called the Annihilare AoS-500, which uses water, salt, and electricity to dispense a menu of solutions for cleaning, sanitizing, and disinfecting.

The machine is just one component in Yale’s campuswide approach to green cleaning, which aims to reduce the exposure of the campus community to chemical, biological, and particulate matter that may be harmful to human health and the environment. And so far, it has impressed the custodial staff at Franklin and Murray.

“The machine is a one-stop-shop cleaning system that is healthy and sustainable for custodial staff, our students, and the community,” says Kirsta MacLellan, the Yale Facilities superintendent at Franklin and Murray. “It has saved us time and money—and with less frequent ordering of different cleaning chemicals, we have fewer deliveries and have eliminated packaging waste.”