PORTLAND – The federal government is investigating whether a West Buxton fire equipment company fraudulently certified fire extinguishers used by schools, businesses and even fire departments.

Federal regulators issued a safety advisory on Nov. 23 to owners of extinguishers serviced by Statewide Fire Equipment Inc.

The regulators said they have evidence that Statewide used four other companies’ identification numbers to show that the high-pressure fire extinguishers it serviced were safe to use. But regulators believe those tests were never conducted.

The high-pressure extinguishers are used by some school systems, fire departments and companies in southern Maine, although federal regulators aren’t sure how many. They shouldn’t be confused with the more-common dry chemical extinguishers, federal officials said.

But because a risk does exist, companies and institutions that have had high-pressure fire extinguishers serviced by Statewide are being urged to contact a licensed testing facility and the U.S. Department of Transportation.

Statewide’s owner, Dale Nason, declined to comment on the investigation, except to say that he was cooperating with the DOT. The business remains open in the interim, he said.

Fire extinguishers, welding tanks, dive tanks and other cylinders filled with high-pressure gas must be tested periodically by facilities licensed by the DOT.