The nation's fireworks manufacturers, proud artisans of our sparkling Fourth of July ritual, are the latest industry to denounce overregulation.

The 70-plus companies that make display fireworks have complained that "burdensome" regulations governing how their Silver Streamers, Blossoms and Sparkling Delight are trucked across the country are opening the market to imports and threaten to drive long-established American families out of what was once a booming business.

Specifically, the fireworks makers are asking the Transportation Department to reclassify fireworks from a class-B explosive to a class-C explosive, a simple change that they contend could mean astronomical savings in the way fireworks are transported, marked and secured. The U.S. Display Fireworks Association has petitioned DOT's Office of Hazardous Materials Regulation seeking the change.

The office is considering the petition and giving the public the chance to comment. Among those with an interest in the outcome is the trucking industry.

A spokesman for the American Trucking Associations Inc. said the proposed changes will be discussed by the Hazardous Materials Committee of the group's Council of Safety Supervisors. "One thing [the change] would do, definitely, is allow more carriers to transport fireworks," the spokesman said. "Whether that change is desirable or not is something the safety supervisors will have to decide."

DOT originally designated fireworks as class B explosives -- the same category as some military explosives -- with an eye for public safety. Class-B explosives that are transported by truck must be attended at all times, meaning essentially that a truck must have two drivers instead of just one. Often a local security guard must also be hired to watch the cargo during overnight rest stops.

But as James Sorgi, president of the American Fireworks Co. of Hudson, Ohio, said, "They have not ever found a truck that has blown up on the highway [while] carrying fireworks."

Sorgi said a small $500 fireworks order from a small town in North Carolina could end up costing the town $1,500 in transportation costs because of those restrictions.

The class-B designation also means the truck must be clearly labeled on the outside to show it contains "explosives." Manufacturers say this amounts to an open invitation for mischief makers or social deviants. "If somebody wants to blow up a building, they'll say 'let's steal that truck,' " Sorgi contended.

For the domestic companies, almost all of them descendants of Italian families who have dominated the industry for generations, the issue is on another level a matter of national pride. "This is the industry that makes the product to celebrate our national birthday, and they're being priced right out of the market by the government," said E. Del Smith, the companies' Washington representative.

Because of the high transportation costs, the manufacturers say, many communities, far from the domestic manufacturers' base in the East and Midwest, are looking for cheaper imports from China, Taiwan and Japan.

Last year the U.S. International Trade Commission reported that imported fireworks' share of the market increased from 72 percent in 1976 to 84 percent in 1982, with China supplying between 60 and 70 percent of all fireworks sold here. But the figures include small firecrackers as well as large display fireworks; some domestic makers also import fireworks and then add their own lifting powder.

"The imports have increased considerably," said George Zambelli, president of Zambelli Internationale, which for decades was responsible for the Fourth of July fireworks display on the Mall. "It's the same as steel and everything else."

"The Chinese don't have to compete with everyone else," said Nancy Rozzi of Rozzi Famous Fireworks. "They set a cheaper price. They pay their workers a cheaper price, and they don't have all the bureaucracy."

"It really is ironic," Rozzi added. "We chuckle at it often, that the Chinese are very slowly taking over the American fireworks industry."

"If you have a company in Ohio that manufacture fireworks and delivers to a city in Alabama, it costs them so much to get the product there before the Fourth of July, they just price themselves out of the market," Smith said. "So the next time, the city in Alabama goes to the cheaper distributor of foreign products."

The rise in the number of imports also raises a safety concern.

The importers "are not the well-identified, reputable old-line manufacturers and they don't adhere to the same safety regulations," Smith said, in a preview of the argument he is likely to present when DOT holds its hearings on the petition.

There may be more to that claim than just rhetoric. In 1982, the Consumer Product Safety Commission warned that a popular fireworks mortar shell made in China could fail to lift properly, spewing flame and sparks along the ground instead of in the air.

"The key goal of [Transportation Secretary Elizabeth] Dole is safety, but the regulations end up denegating safety," Smith said.