The US Department of Labor's Occupational Safety and Health Administration (OSHA) said while no serious injury occurred the potential was evident after the 18 December inspection at a Chelmsford, Massachusetts manufacturing site.
OSHA found plant workers exposed to crushing, struck-by and caught-in machinery hazards while setting up a press.
Proper procedures to shut down the machine and lock out its power source before performing the setup were also not followed, the agency said.
Jeffrey A. Erskine, OSHA's area director for Essex and Middlesex counties in Massachusetts, said: "For the safety and well-being of its workers, an employer must take effective steps to ensure that required safeguards are in place and constantly utilized at all facilities."