The wall-to-wall inspection, which OSHA is conducting at the mill, is rare in the steel industry because of the commitment of time and resources involved.
At Rocky Mountain Steel, the Pueblo subsidiary of Oregon Steel Mills Inc., the agency expects the current inspection to last between one and two months.
The United Steelworkers of America (USWA) welcomed the start of the comprehensive inspection.
"We are glad to see OSHA in the mill because somebody has to stop the carnage before another worker dies," said Ernie Hernandez, president of USWA Local 2102, which represents production and maintenance workers at Rocky Mountain Steel.
USWA representatives said the deteriorating safety conditions at the company are underscored by the deaths of two workers in less than 10 months.
"We have tried for years to teach this company that safety cannot be an afterthought," said Hernandez. "They obviously haven't heard us, but hopefully they will hear what OSHA has to say."
The latest inspection of the Rocky Mountain Steel Mill follows other recent safety and health violation enforcement efforts OSHA has taken against the company.
In July 1999, Oregon Steel's Rocky Mountain Steel Mills subsidiary received the second-largest OSHA fine in Colorado history -- $400,000 -- for violations of health and safety law at the Pueblo mill.
Since then, the company has been fined for further violations, including those which involved the death of one worker and the double amputation of a second workers arms.