WASHINGTON -- Coca-Cola Co. was sued as part of an effort to force soft drink makers to eliminate ingredients that can form cancer-causing benzene.

The complaint against the soft drink giant came Friday as two smaller companies settled a lawsuit over benzene, which is linked to leukemia.

"I think if they understand that consumers, and perhaps courts, expect them to eliminate this problem, they will," said Boston lawyer Andrew Rainer, who represents parents who sued to force the companies to stop using ingredients that form benzene.

A Coca-Cola spokesman said the lawsuit is not about consumer safety but about lining lawyers' pockets.

The Food and Drug Administration "has closely reviewed beverages for the presence of benzene in soft drinks several times in the past and each time has found no public health issue," said Coke spokesman Ray A. Crockett.

Similar lawsuits, all filed by parents of children who drink the beverages, are pending in federal court in Kansas, Massachusetts and New Jersey and in state court in Florida and California.

The first parent to sue, Timothy Newell of Boston, was a neighbor of one of the attorneys; other parents joined after learning about the lawsuits. The parents want companies to change their drink formulas and to refund money spent on the beverages.

Plaintiffs added Coke's Vault Zero energy drink to the Kansas lawsuit, which also targets PepsiCo Inc.'s Diet Wild Cherry and Kraft Food Inc.'s Crystal Light Sunrise Classic Orange.

Benzene can form in soft drinks containing vitamin C, also called ascorbic acid, and either sodium benzoate or potassium benzoate.

Scientists say factors such as heat or light exposure can trigger a reaction that forms benzene in the beverages.

According to the suits, independent laboratory tests found benzene in the drinks at levels above the federal limit for benzene in drinking water.

The FDA found similar results on unidentified brands in sampling from 1995 through 2001 and said it would do more tests.

The companies that settled -- Atlanta-based In Zone Brands Inc., maker of BellyWashers, and Preston, Wash.-based TalkingRain Beverage Co. -- denied that their products caused any harm.

But they agreed to change their ingredients in April and May, after the suit was filed. They also agreed to refund or replace drinks made before the switch in ingredients.

District of Columbia Superior Court Judge Mary Terrell dismissed that case Friday morning.

BellyWashers are juice drinks that come in reusable bottles featuring Spiderman, Hello Kitty, Scooby Doo and other well-known characters.

Crockett, the Coke spokesman, said Vault Zero is safe.

"There is no supporting documentation to prove how these lawyers conducted these tests," Crockett said.

"Their own press release indicates that they have abused the product with heat prior to testing," he said.

FDA officials say there is no safety concern and that levels are still relatively low compared with other sources of exposure to benzene.

The soft drink industry agrees and says the amount of soft drinks people consume is much less than the amount of tap water they are exposed to.

As part of the settlement, the smaller companies agreed to pay $35,000 each.

Rainer, representing the plaintiff parents, said most of the money will pay legal costs.