With many safety inspections suspended because of the federal government shutdown, observers say there's an increasing risk for workers. At least half of the staff members at federal safety agencies are furloughed, and many operations that normally keep workers safe on the job have stopped.

Former New Jersey Governor Christine Todd Whitman has been a leader in efforts to improve chemical plant safety for years. She pointed to the stalled investigation into the huge explosion at the West Fertilizer Company in Texas that killed 15 people last April.

"This is one of those areas where it should bring home to people the importance of Congress doing its business and getting us back on track, because we can't afford to have this lapse and continue any longer," Whitman declared.

Half of Mine Safety and Health Administration personnel are off work, as are 90 percent of the employees at OSHA.

According to Ronald White, the director of regulatory policy at the Center for Effective Government, federal safety inspectors and investigators have key roles in keeping the nation's construction sites, mines, factories and food processing facilities from becoming deadly, and the longer those work sites drift without inspections, the more dangerous they become.

"The bottom line is that the public and workers are going to see less protection while this government shutdown continues, and it's only going to increase in term of potential risks over time," White warned.

Some conservatives have argued that shutting the government down doesn't matter, but White said many of the federal safety efforts are nearly invisible, until something goes wrong. He pointed to the researchers at the Centers for Disease Control and Prevention, who track multi-state outbreaks of food contamination. At first, most of them had been furloughed as well.

"Because of this most recent outbreak of salmonella in chicken, that has sickened quite a large number, some of those people have actually now in the last few days been called back," he said.

It remains unclear just when the federal government will fully reopen.