Neatly attired in a navy blazer, gray flannels and tie, Frank Paul Young Sr. looks more accustomed to presiding over company meetings than sitting at the defendant's table at his own criminal trial.

But today, the 43-year-old general manager of American Recovery Co. Inc., the largest oil recycling firm in Maryland and one of the largest in the nation, went to trial in Baltimore County Circuit Court on charges of directing the dumping of thousands of gallons of hazardous waste into Baltimore Harbor and conspiring to block a state grand jury investigating the dumping.

With his indictment in August 1984 on eight counts of illegally disposing of hazardous waste and conspiracy, Young joined the slowly growing ranks of corporate executives nationally who have been accused of criminal wrongdoing by allegedly condoning, or as prosecutors allege in Young's case, directing the improper disposal of hazardous chemical wastes.

Maryland Attorney General Stephen H. Sachs alleges that Young, among other things, falsified documents detailing disposal procedures of hazardous waste and directed that PCB-contaminated oil be mixed with clean oil and sold as a recycled product. Young has pleaded innocent to the charges.

Since 1982, Maryland's Hazardous Waste Strikeforce has concluded 37 criminal prosecutions against polluters in the state, individuals and companies, losing only one case in Garrett County. Nationally, the U.S. Department of Justice's Environmental Crimes Unit has indicted 126 individuals or companies on industrial pollution charges since 1982, garnering 97 convictions.

"Violations of hazardous waste laws are being seen across the country as very serious offenses -- crimes in which there are victims, crimes of violence," said Judson Starr, director of the national unit.

In February, American Recovery Co. pleaded guilty in Circuit Court to illegally storing and disposing of a wide variety of waste, including oil laden with cancer-causing PCBs. The company was fined $350,000 -- the largest fine ever imposed for a violation of Maryland's hazardous waste laws, according to state officials.

Last December, Young's codefendant, plant manager John William Driscoll, 35, pleaded guilty to two counts -- one of conspiring to violate Maryland's controlled substance laws and the other of dumping hazardous wastes -- which carry up to five years in prison and fines of $100,000. Driscoll will testify for the prosecution during the trial, which is expected to last several weeks.

The jury is made up of 10 women and two men, most of whom live near the American Recovery plant, which is on Bethlehem Steel property at the edge of the city harbor in Baltimore County. The jurors must sit through largely technical, often tedious testimony centering on oil recycling techniques, complex state hazardous waste laws and the dangers of various chemical wastes -- previewed yesterday in Assistant Attorney General Jane Barrett's opening arguments.

Among the jurors is a man who has asbestosis -- a rare form of cancer caused by exposure to asbestos, a man-made fiber now banned because of the health threats it poses.

But the panel must wait to hear Paul Mark Sandler, Young's defense attorney, detail the executive's version of the events. Sandler told Baltimore County Circuit Court Judge Joseph F. Murphy Jr. that he would wait until the prosecution finishes presenting its case before he opens arguments for the defense. And Murphy warned reporters yesterday not to question Barrett or Sandler because they would not comment until the case goes to the jury.

Young faces up to five years in prison on each count if convicted and up to $1.6 million in fines. He has no prior criminal record, according to state law enforcement authorities.