The city of Beaufort and town of Port Royal were awarded a joint fire rating Thursday that local officials say might lower insurance premiums for businesses and boost economic development.

Effective May 1, the Beaufort-Port Royal Fire Department will share a Class 2 Insurance Services Office fire rating, according to a news release. The ISO rating is one often used by insurance companies to measure a community's ability to provide fire protection. One is the highest rating, and 10 is the lowest, according to the ISO.

It is the first time the two municipalities have pursued a joint ISO rating.

Beaufort was last inspected in 1981 when it received a Class 2 rating, which put the city's department in the top 2 percent of the 43,000 fire departments rated by ISO.

Inspectors gave Port Royal a 3/9 rating in 2004, with the town's outlying areas receiving the less-desirable 9 rating.

ISO inspectors visited the Lowcountry in August to grade the two departments, the release said.

Port Royal town manager Van Willis said pursuing the joint rating was in the best interest of both towns.

"It was not easy bringing these two ratings into one single ISO classification, but we knew it was possible, and better yet, it was the right thing to do," Willis said in a statement.

Beaufort Mayor Billy Keyserling said the lower rating could help spur economic development.

"Getting an ISO 2 rating for Port Royal will have a dramatic effect on the desirability of the Port (of Port Royal) property for development," Keyserling said. "And as we continue to bring redevelopment opportunities to Beaufort and the Boundary Street Corridor, the lure of lower fire insurance premiums will certainly help."

The Burton Fire District recently underwent a similar ISO evaluation, and the results are expected soon, said Dan Byrne, district spokesman.