A bill authorizing free health care for U.S. armed forces veterans involved in secret chemical-weapons testing more than 40 years ago has passed the U.S. House, and a similar proposal may face action this week in the Senate.

U.S. Rep. Denny Rehberg, R-Mont., who's been pushing more than seven years to get recognition and health care for veterans who underwent the testing, said Saturday he hopes the bill won't stall in the Senate, as it has in the past.

"It's frustrating, because you'd like to think if you can get it through one (legislative) body, the other body could get it done," he said. "It would be a real shame if it doesn't, because there are people who are directly affected."

U.S. Sen. Jon Tester, D-Mont., said Monday a Senate version may be on the floor this week, where he hopes it can be approved.

"Veterans who were unknowingly used as military experiments deserve the best medical care this country has to offer, without having to cut through government red tape," he said in a statement.

The bill that passed the House last Thursday extends a number of health-care programs for military veterans.

Within the bill is language providing free health benefits to the 500 or so veterans involved in part of the Shipboard Hazard and Defense project, known by its acronym, SHAD.

SHAD was part of Project 112, a Cold War-era testing of biological and chemical weapons, ordered by then-Defense Secretary Robert McNamara because the government wanted to catch up to the Soviet Union on chemical warfare, veterans who participated said.

Hundreds of servicemen were stationed on tug boats in the Pacific Ocean in the 1960s, where they were sprayed from the air with chemical and biological agents, including rabbit fever, an anthrax-like substance, and nerve gas.

The soldiers were inside sealed quarters when hazardous material was sprayed on the boats, but those on board said paper filters designed to prevent material from getting through air ducts often deteriorated.

Participants have said they believe they also were exposed to cleaning agents and other materials that are cancer-causing.

One of the participants was Navy veteran John Olsen of Billings, who brought the issue to Rehberg's attention in 2001.

Olsen said he's suffered from skin cancer, prostate cancer, an adrenal tumor and a rare form of hypertension, which he believes may be related to his SHAD experience.

The language in the House bill says veterans involved in the SHAD testing get access to free health care at Veterans Administration health facilities - without having to prove their health problems are "service-connected."

VA Health Care provides care to veterans, but the care is free only for those with certain disability ratings tied to service-related illnesses or injuries.

"It's important that VA facilities open their doors to SHAD vets across the nation," Rehberg said last week. "Putting the provision in this bill is the best chance we have of getting the problem fixed quickly.

"It doesn't seem right to ask them to wait any longer."