A consumer group sued the federal government Thursday, saying that salt is killing tens of thousands of Americans and that regulators have done too little to control salt in food.

Despite advisories to take it easy on sodium, Americans are now consuming about 4,000 milligrams a day - nearly double the recommended limit to keep blood pressure under control, the Center for Science in the Public Interest said.

So the CSPI renewed a lawsuit first filed in 1983 to ask federal courts to force the Food and Drug Administration to declare sodium a food additive instead of categorizing it as “generally recognized as safe.”

This would give the agency the authority to set limits for salt in foods.

“There is no way the FDA can look at the science and say with a straight face that salt is ‘generally recognized as safe,”’ CSPI executive director Michael Jacobson said in a statement.

“In fact, salt is generally recognized as unsafe, because it is a major cause of heart attacks and stroke. The federal government should require food manufacturers to gradually lower their sodium levels.”

The CSPI said Americans get most of their salt in processed and restaurant foods. In 1983 the FDA had just begun requiring labels describing sodium content on some packaged foods so the court decided to wait and see how it worked.

The new lawsuit, filed in the United States Court of Appeals for the District of Columbia, contends that it has not worked well because salt content in foods is higher than ever.

“FDA is currently evaluating CSPI’s report on salt, including the recommendations it contains,” Kathleen Quinn, a spokeswoman for the agency, said.

The government says Americans should try to keep sodium to about 2,300 milligrams a day. “This is about 1 teaspoon,” the American Heart Association says.

Salt is not found only in the saltshaker. For example, a teaspoon of baking soda contains 1,000 mg of sodium.

Patients with high blood pressure and others at high risk are told to eat even less salt - 1,500 mg a day. “Nevertheless, sodium intake has increased steadily since the 1970s,” the CSPI said in a statement.

“The medical community has reached a consensus that diets high in sodium are a major cause of high blood pressure as well as pre-hypertension, or blood pressure just short of high blood pressure,” said Dr. Stephen Havas of the University of Maryland School of Medicine.

“Today roughly 65 million Americans have high blood pressure and another 45 million have pre-hypertension.”

The CSPI issued a report saying that processed foods and restaurant fare contribute almost 80 percent of sodium to the U.S. diet. Frozen dinners are especially high in salt, the report finds.

Depending on the brand, some salad dressings contain nearly a quarter of the day’s allowance of sodium while others are low in sodium, the report finds.

One chain restaurant’s breakfast contains two days’ worth of sodium - 4,460 mg - the CSPI report said.

Chinese restaurant meals can be especially high, too. “A typical order of General Tso’s chicken with rice has 3,150 mg,” the group said.

Dr. Claude Lenfant, president of the World Hypertension League and a former head of the National Heart, Lung and Blood Institute supported the report. “If we could reduce the sodium in processed and restaurant foods by half, we could save about 150,000 lives per year,” he said.