Riders may have noticed the blue lights on Island Transit buses that indicate the new air purification systems are working.

The agency is installing the technology on all of its buses and has added the technology to at least 75% of its fleet, according to a spokesperson.

Some riders will see the metal boxes mounted in the front of the agency’s smaller buses, and others will see them at the back of the larger buses.

The agency paid for the United Safety Active Air with RGF PHI Cell TechnologyAir Active Purification System with local sales tax revenues. The air cleaners on the smaller buses cost $1,750 and the ones on the larger buses cost $3,400. The agency’s draft 2022 budget shows the technology will cost about $121,000.

Its job is to continually sanitizes the air and surfaces to reduce passengers’ risk of being exposed to the coronavirus, swine flu, Avian flu, MRSA, E. coli, bacteria, mold and carcinogens.

The system turns on when the driver turns on the bus and is designed to run silently.

Kitsap Transit in Bremerton and Link Transit in Wenatchee have also added the technology to their fleets.

The new additions are part of Island Transit’s health safety measures during the pandemic, which includes masks for all passengers, plexiglass dividers and daily sanitizing of vehicles’ interiors.