The Justice Department set out for the first time yesterday to hold producers of toxic waste just as liable for its disposition as the operator of the site where it is dumped.

The department asked the U.S. District Court in Baton Rouge, La., for an injunction to halt 12 oil and chemical companies from disposing of any wastes, hazardous or otherwise, at two sites near Baton Rouge where dozens of carcinogens and poisons are leaking into the environment.

Both the 55-acre Brooklawn site, which is still operating, and the nearby nine-acre Scenic Highway site, which is closed, are owned by Petro Processors of La. Inc. The complaint said the sites have long been used for the disposal of chemicals "from a variety of industries located in the general Baton Rouge area."

The Brooklawn site is a low-lying swampy flood plain and consists of four or five pits or ponds. The chemicals leak through crumbling dikes or escape by periodic flooding, the complaint said.

The Scenic Highway location is essentially a large vertical hole drilled in a bluff overlooking a bayou that drains into the Mississippi River. Filled with waste, it was closed several years ago and covered with plastic and a layer of earth. But the plastic has disintegrated, and the earth has washed away, so that the wastes "threaten to enter drinking water either drawn from the Mississippi River or from nearby shallow wells," the complaint continued.

Chemicals found at the two sites include lead, chromium, vinyl chloride and a variety of chlorinated hydrocarbons associated with liver diseases and death. One sample from Brooklawn, the complaint alleged, contained 11,000 parts per million of chlorinated hydrocarbons, where as little as 1.4 parts per million can kill aquatic life.

A supporting memorandum documenting the pollution said that siphon hoses "similar to size and appearance to fire hoses" had been spotted and photographed running from the Brooklawn site directly into the bayou. The next morning, the memo said, "it is estimated that the level in the pit being drained through the siphon hose dropped two or three feet, releasing thousands of gallons of water into the bayou and subsequently into the Mississippi."

The Justice Department asked the court of order the "defendant generators" to repair the dikes and plastic sheeting and install fences around the areas after doing tests and sampling.

In previous suits the government has gone after either the waste transporters or the owners of the disposal site. "This was the first case in which we had the evidence to make the direct linkage between the causer and contributor to the problem and the dumpsite itself," said Anthony Roisman of Justice's hazardous wastes division.

"At the time we used the site, it was an acceptable way of doing things," said Tom Joffrion of Dow's Louisana division. "It was not until afterward that problems developed." The company put chlorinated tars and wastes from its chemical plant in Plaquemine, La., at the sites for 18 months, he said. He cited a Louisana state study that found the sites a "serious" hazard but not the "imminent" hazard the government suit alleges."

The "imminent" label is necessary for the government to obtain a preliminary injuction.

Shell Chemical spokesman Kitty Borah said the firm burned waste oil at the site but that such oil is not considered hazardous. The complaint, however, charges that even the dumping of nonhazardous wastes contributed to the problem by "further overloading the disposal area and causing further waste to escape."

Bill Smith of Allied Chemical said his company had not used the dumpsites for some time and had been absolved of wrongdoing in an earlier civil suit brought by an area resident.

All the companies contacted expressed dismay that the government had rejected an offer to finance independent study of the sites and their contents and had filed suit when they refused to agree to clean the areas up without such tests. "This work is an essential first step to resolving the matter," said an Exxon spokesman.