SOUTH PORTLAND — The city’s aggressive fire inspection program has pushed the South Portland Fire Department’s rating by a national insurance risk assessment agency into the top 100 of more than 40,000 departments nationwide, the city’s fire chief said Saturday.

The spotlight on South Portland’s inspection program comes as fire departments in Portland, Brunswick, Bangor and several other Maine communities aim to strengthen their inspection regimens for rental units in the wake of a Portland fire last Nov. 1 that was Maine’s deadliest in decades.

Fire Chief Kevin Guimond said South Portland is the first city in Maine to receive a Class 1 rating from the Insurance Services Office, a New Jersey-based organization that advises insurance companies throughout the United States and beyond.

The high rating could reduce insurance rates as much as 4 percent for some home and business owners, Guimond said, although property owners likely would have to request a reduction to get one.

Guimond said South Portland has had a Class 2 rating since the 1980s, and was last reviewed by the ISO in 2010, when it scored 89 of a possible 100 points. The increase came this year, Guimond said, because the ISO has stepped up its attention to “community risk reduction” efforts, which pushed South Portland’s score to 93.

“That helped us a lot,” Guimond said Saturday. “We’ve had a very active inspection and code enforcement program since the 1980s. We do about 1,800 inspections a year. We try to prevent fires as well as put them out and try to keep people safe.”

South Portland firefighters inspect all commercial properties and all apartment buildings with three or more units at least once a year, Guimond said. They also inspect all fuel tankers that dock at the city’s seven fuel terminals and undergo rigorous training to respond to potential spills or fires at more than 100 fuel storage tanks in the city, he said.

Guimond credited a significant portion of South Portland’s high rating to the Portland Water District, which provides water from Sebago Lake to more than 50,000 customers in 11 communities throughout Greater Portland.

“Forty percent of the score is water supply,” Guimond said. “We have over 600 hydrants. We’re expected to have a minimum flow rate of 750 gallons per minute, and our flow rate is over 1,000 gallons per minute. So we owe the Portland Water District a lot.”

ISO representatives flew into South Portland on Wednesday to deliver the news of the Class 1 rating, which takes effect Feb. 1, 2016. The ISO also reviews each fire department’s staffing levels and training, equipment type and condition and communications capabilities, among other things, according to the ISO report.

But it’s the assessment of South Portland’s inspection program that pushed the department ahead this year, Guimond said, at a time when other Maine communities are trying to improve their efforts.

“We’ve been inspecting regularly since the 1980s and we’re finally getting recognized for it,” Guimond said. “It’s a national model that’s being pushed now and we happened to be ahead of the curve.”

Five people were killed in the early morning hours of Nov. 1, 2014, when fire swept through a duplex on Noyes Street in Portland that was divided into multiple apartments. A sixth person later died of injuries sustained in the fire.

Investigators determined that a cigarette discarded on the front porch started the fire. They also found that the building had no functioning smoke detectors or adequate means of egress. A grand jury indicted the landlord, Gregory Nisbet, on six charges of manslaughter, as well as misdemeanor code violations for not having working smoke detectors, clear stairwells and a second means of escape from an upstairs bedroom.

The incident focused a critical spotlight on Portland’s lax fire inspection program in a city with thousands of rental units. The city has since stepped up enforcement, created a new housing safety office and hired a director to oversee three new inspectors. That office will be funded with a $35-per-unit fee charged to landlords, although owners could receive credits for safety measures installed in their buildings.

According to a 2013 online newsletter produced by the city of Portland, the ISO has reviewed the Portland Fire Department “every 10 years or so” and issued its last rating in 2012, when it was ranked at Class 2 – the same as two previous evaluations – with a score of 84.55.

Whether South Portland residents will see a reduction on their homeowner’s insurance costs because of the Class 1 rating remains to be seen. Guimond said some insurance companies recognize the ISO rating and others don’t. Large commercial property owners likely will see the biggest reductions.

Guimond suggested that property owners call their insurance companies after the new rating takes effect on Feb. 1.

“Insurance companies probably aren’t going to call you and say, ‘We’re going to cut your rates,’ ” Guimond said.