SEATTLE – The warning is on the back of the Coleman Co. propane heaters: “For outdoor or well-ventilated construction use only. Never use inside house, camper, tent, vehicle or other unventilated or enclosed area.”

The families of five people who were killed by carbon monoxide poisoning while camping in southwestern Washington’s Lewis County this year say the bright orange labels weren’t enough to prevent the deaths.

In two federal lawsuits filed Thursday, they argued that the labels aren’t clear about what “well-ventilated” means and that simple manufacturing changes could have saved the lives of their loved ones and at least 75 other people who have died using Coleman heaters around the country.

“That sticker is not on there to save lives,” attorney Jeffery Campiche said. “It’s put on there to immunize them against liability. You can design it to erase the risk, or you can put a sticker on it.”

In one case, Mari Daniel of Puyallup is suing for wrongful death after her husband and her father were killed during a hunting trip Sept. 15. They were using a Coleman 5045 PowerMate heater to warm the 28-foot trailer they were sleeping in; they had windows open while the heater was on, Campiche said. A third member of the hunting party survived.

In the other case, the guardian of 5-year-old Cody Ongpituk is suing because his father, his mother and his 13-year-old sister died in May after using the same model heater in the panel truck where they sometimes slept. The Ongpituks, of Seattle, were staying in Lewis County to sell Thai food during a Memorial Day festival.

Coleman, based in Wichita, Kan., declined to comment on the lawsuits.

Campiche said Coleman had a responsibility to ensure its heaters are safe not only when used as intended by the company, but also when they are misused in a way that the company could reasonably foresee. And the company knows that many people use the heaters to warm up their tents or campers – mistakenly believing that if they crack open the windows while the heaters are running, they’ll be safe, he said.

Coleman should have changed its design so the heaters would automatically shut off before levels of the odorless, colorless gas build up, as other companies have done, Campiche said.

Coleman no longer sells the model at issue in the lawsuits, but an estimated 1 million similarly designed Coleman heaters remain in use worldwide, Campiche and other attorneys involved in the cases said. The heaters have been manufactured since 1984; a precursor to the PowerMate model was called Focus.

In West Palm Beach, Fla., a jury awarded $10 million to the family of an electrician and his stepson who died in 1999 when a Coleman Focus heater filled their camping tent with carbon monoxide.

Another couple died while camping in Lewis County in 2000 when their tent filled with carbon monoxide. Coleman settled that case for an undisclosed sum.

The two lawsuits seek damages for pain and suffering and lost wages, as well as punitive damages against Coleman.