Oahu’s new fireworks ban appears to be one of the main reasons that no one went to a hospital emergency room here with a fireworks-related injury this past Fourth of July, a state official said Monday.

For the first time in nine years, the state Department of Health recorded no fireworks-related injuries treated in Oahu’s emergency rooms for a July 4 holiday period.

“To get to zero is really impressive,” said Dan Galanis, epidemiologist for the department’s Injury and Prevention and Control Program. “It’ll be interesting to see how the numbers decrease around New Year’s.”

The Fourth of July weekend was the first major holiday after a county ban on nearly all fireworks that went into effect Jan. 2. Oahu residents may buy and use only firecrackers.

Sparklers, fountains and other types of fireworks are banned on Oahu.

From 2003 — when the department began tracking such injuries — through 2010, an average of 17 people were treated in Oahu hospital emergency rooms for fireworks-related injuries, Galanis said. Last year 16 people were treated.

In contrast, this year nine people were treated for fireworks-related injuries on the neighbor islands, the most since 2006. The total includes four each on Maui and Hawaii island, and one on Kauai.

Most of the patients were injured while holding or setting off fireworks, Galanis said. Patients ranged from 7 to 27 years old.

Cedric Caagbay, clinical operations manager at the Queen’s Medical Center, said first- and second-degree burns make up most of the fireworks-related injuries he has treated in the Queen’s emergency room.

“We see a whole gamut of patients, from children to adults, and the injuries are usually due to negligence,” Caagbay said. “We encourage children to follow directions and always have parental supervision.”

The Honolulu Fire Department reported fewer fireworks-related fires during Fourth of July: four, down from 27 last year.

Oahu residents also bought a lot fewer firecracker permits this year — 93, compared with 174 for the 2010 Fourth of July period. Each $25 permit entitles an adult to buy up to 5,000 firecrackers. There is no limit on the number of permits a person can buy.

Linda Rosen, the Department of Health’s chief of emergency medical services, said she was surprised and pleased to see there were no reports of fireworks-related injuries.

“People don’t always comply with the law, so I’m not confident we’ll continue to see no injuries,” Rosen said. “But I am confident we’ll see less injuries because the law was enacted.”