While thousands of Iowa cooks will sweat over a propane grill this holiday weekend, the industry’s focus is on higher-volume uses of the fuel. More than eight-Million homes in the U-S depend on propane for their primary heating and cooking energy source. Debra Grooms, head of the Iowa Propane Gas Association, says commercials promoting use of propane are running now in major markets in Iowa. The TV ads ran in the Country Music Awards recently and in eastern Iowa there are radio and TV commercials running in local markets this spring. The state association offers ongoing training for Iowans who work in the heating, cooling and plumbing business because they use the fuel as part of their industrial work. In January 2003 a state law was passed requiring anyone who works with propane to get documented training every three years.