Ingredients: Take seven years of the fewest significant safety standards in U.S. history and depleted resources that have made it more difficult for the Occupational Safety and Health Administration to enforce workplace safety measures. Add political appointees who are often former officials of the industries they now supervise. Mix in eased regulations and weakened standards that favor businesses instead of workers. The tragic result, as we have seen at the Imperial Sugar refinery near Savannah, is a recipe for disaster.

Two years ago, an independent federal agency charged with investigating chemical accidents recommended that OSHA issue a new standard to prevent fires and explosions caused by combustible dust in general industries —- including sugar refineries.

By law, the Bush administration's OSHA was supposed to respond to this agency's recommendations within six months. Tragically, OSHA's response failed to protect the safety of America's workers.

On Feb. 7, an explosion rocked the Imperial Sugar Co. In this particular tragedy, sugar dust found an ignition source and created an instantaneous inferno that has now claimed 12 lives and left many more in such a condition that they exist in a medically induced coma to spare them the suffering of their injuries.

Sadly, this accident was predictable and preventable.

In 2006, OSHA ignored a recommendation from the U.S. Chemical Safety Board —- an independent federal agency charged with investigating industrial chemical accidents —- to issue a rule that could have prevented the tragedy at Imperial Sugar and other combustible dust explosions. That year, the CSB conducted a major study of combustible dust hazards following three work-site dust explosions that killed 14 workers in 2003. The CSB report also noted that a quarter of the explosions between 1980 and 2005 occurred at food-industry facilities, including sugar refineries. In only one or two investigations were these incidents caused by mechanical mysteries that were either unforeseen or unpredicted.

The evidence is as clear today as it was in 2006. Industrial explosions of horrific magnitude are caused by finely divided combustible materials not otherwise viewed as dangerous, such as sugar and cocoa. These explosions could be ignited by low-energy sparks. Since there are thousands of ignition sources for these powerful explosions in sugar refineries, control of the fuel source is imperative.

Standards and codes have existed for years for OSHA to build upon and eliminate this type of explosion. In 1987, OSHA issued the Grain Handling Facilities Standard as the result of grain-dust explosions in the late 1970s and early 1980s. This standard has effectively reduced the number and severity of combustible grain-dust explosions in the grain-handling industry and saved countless lives. At the time, there was a great debate over including other general industry combustible dusts such as food, wood, plastic and metal. In the end, pressure from lobbyists representing these industries successfully blocked any plans to expand this standard, and the Grain Handling Facilities Standard stopped short of regulating combustible dust in industries outside the grain industry.

Once again, nothing was done —- which leads us to this question: What is the mission of OSHA but to work to protect the safety and health of American workers from dangerous events that are preventable?

America's workers are paying the terrible price for OSHA's inaction that follows a seven-year pattern of watering down safety standards and ignoring scientific evidence and even its own rule-making guidelines. OSHA must act now and follow the 2006 recommendations of the CSB before more workers are killed or horribly injured.

Anything less is a recipe for disaster.

> Carolyn Merritt is the former chairwoman of the U.S. Chemical Safety Board.

> Jackie Nowell is director of the Occupational Safety and Health Office at the United Food and Commercial Workers International Union.