A potentially dangerous chemical began leaking from a tanker truck yesterday, slightly injuring three people and forcing the temporary evacuation of a truck weighing station 35 miles south of Washington.

The incident occurred less than a week after a three-year university research project cited Northern Virginia highways as having a high potential for serious truck accidents.

The latest incident came at the Dumfries weighing station on Interstate 95 at 2:19 a.m. yesterday when the driver of a Central Transport Inc. truck noticed a small leak in one of the truck's tanks.

"The truck was carrying three separate tanks, with a size of 2,500 gallons per tank, of methyl acrylate, a chemical used in making plastics with a flashpoint of only 27 degrees Fahrenheit," said Prince William County Fire Marshal Ed Lowe. "The chemical is explosive when it comes in contact with air."

The driver apparently noticed the spill after weighing station employes told him that his truck was overloaded on the front and rear wheels, Lowe said. He added that the leak "was only about a gallon every three hours."

However, one Prince William County firefighter and two Prince William County policemen were treated at Potomac Hospital in Woodbridge after complaining of eye and throat irritations at the scene. Lowe said the station was evacuated for "a few hours," but that the highway remained open.

"The truck was on its way from Cell River, S.C., to Belvidere, N.J.," Lowe said. "The trucking company, out of High Point, N.C., sent out another tank truck that arrived five hours later to collect the chemical."