The fire broke out around 2 p.m. on the second floor of a four-story apartment building above a trio of storefronts at the corner of Anderson and Lincoln avenues.
A paint thinner apparently caught fire, sending smoke through the hallways.
Sgt. Chris Merrill dashed through the smoke to the upper floor to get residents out, while Officers Jason Messina and Marc Moschella and Deputy Chief Vincent Capano cleared the rest of the 20 or so apartments.
Merrill was treated at the scene for minor smoke inhalation and released.
Firefighters knocked down the main body of the three-alarm blaze within a half hour.
Among those providing mutual aid were firefighters from Edgewater, Englewood, Englewood Cliffs, Fairview, Fort Lee, Leonia and Ridgefield.
Click here to follow Daily Voice Saddle Brook-Elmwood Park and receive free news updates.