Seven months after Palm Beach County commissioners came within one vote of removing fluoride from the county’s drinking water, a statewide shortage of the compound has forced utility officials to stop using it.

County Administrator Bob Weisman said Monday that the utility department already has run out of fluoride at its water treatment plant in western Delray Beach. Officials may be forced to stop adding the compound at four other county treatment plants if they don’t get a shipment in the next 30 days, he said.

Within the past week, roughly a quarter of the county’s utility customers have stopped receiving fluoride in their tap water because of the shortage. It affects water piped to customers between Lantana and Yamato roads, Weisman said.

Palm Beach County isn’t alone. Officials across the state also say they are having a hard time getting fluoride for their plants.

Distributors say the compound, a byproduct of phosphate mining used to prevent tooth decay, has been in short supply for about 18 months, since one of the state’s major mining companies went out of business.

A production problem at another mining operation caused the recent crunch. Although it is expected to be temporary, distributors say the cost of fluoride has skyrocketed because so few companies produce it.

“As the population has grown, as demand has grown, it makes everything a little bit tighter,” said Jeff O’Neill, vice president of Harcros, one of Florida’s largest distributors of fluoride. “Whatever we can get, we are getting.”

Ron Cartwright, president of The Dumont Co., which distributes fluoride to about a dozen local governments across the state, said some utilities must wait up to six weeks for a shipment. At least one of Cartwright’s utility customers has decided to stop adding fluoride to its water until the supply improves, he said.

As a result of the shortage, the cost of fluoride has gone up roughly 25 percent since October, Cartwright said.

“Fortunately, it’s not something that’s absolutely mandatory to safe drinking water,” Cartwright said.

Fluoride occurs naturally in the county’s water supply at 0.2 milligrams per liter. The county’s fluoridation system increases that amount to 0.8 milligrams per liter, a concentration within levels recommended by the U.S. Centers for Disease Control and Prevention.

Small pumps at the county’s water treatment plants inject fluoride, a liquid, into drinking water. The liquid is added by the drop. A tiny bit is enough to treat hundreds of gallons of water.

Palm Beach County commissioners decided two years ago to activate the fluoridation systems at the county’s water plants after debating the issue for more than a decade.

Last year, commissioners again voted to keep the fluoride flowing, despite a recommendation from Weisman to stop the practice.

Weisman based his recommendation on a study by the National Research Council that called for additional research and recommended that the Environmental Protection Agency’s drinking water standard for fluoride – now set at a maximum concentration of 4 milligrams per liter – be lowered. Health concerns raised in the study include fluoride’s long-term effect on tooth enamel and bone strength.

Palm Beach County health officials have maintained that fluoride is safe. Opponents argue that it is still unclear how fluoride affects the entire body. Doses of fluoride cannot be regulated because people drink varying amounts of water, they say.

Naomi Flack, a member of the steering committee for the South Florida Citizens for Safe Drinking Water and the advisory board of the Fluoride Action Network, said it’s time for commissioners to reconsider their decision.

“I think it’s very fortunate for those people in the county who will again be getting unfluoridated water,” Flack said. “I think it’s time for the county to bring the issue up again.”

Health department spokesman Tim O’Connor said Monday that officials are aware of the shortage and don’t expect it to have any lasting effect on dental health.

“At this point, people should follow their normal routine,” O’Connor said. “The main thing is that they continue their normal habit of brushing.”

Seven municipalities in Palm Beach County also fluoridate their drinking water: Belle Glade, West Palm Beach, Delray Beach, South Bay, Pahokee, Wellington and Boynton Beach.

Officials in Delray Beach, West Palm Beach and Boynton Beach said Monday they were not affected by the shortage. Neither were officials in Port St. Lucie, a city spokeswoman said.

In Broward County, Plantation officials said they are worried the city could run out of fluoride if they don’t receive a new shipment. Utility officials ordered 8,000 gallons for each of its two treatment plants but have received only 800 gallons.

“It’s starting to run short,” said Hank Breitenkam, the city’s utilities director. “We only have so much supply at our plant.”

The shortage has prompted a string of e-mails among utility officials across the state. One official said she found a distributor in Texas who was willing to ship fluoride from Louisiana, but for four times as much as she usually pays.

Utility customers in Palm Beach County should not see a difference in the taste or color of their tap water, Weisman said.

“People won’t know the difference,” he said. “Using fluoride is something that requires long-term use. If there is a short period without it, there won’t be an effect.”