In 2007 OSHA put in place its Combustible Dust National Emphasis Program (NEP) to inspect facilities that produce combustible dust and pose the potential threat of a dust explosion. NEP focused on 64 industries (SICS / NAICS) including many of the aforementioned industries. The NEP inspections found an average of 6.5 Federal Violations per facility compared to other facilities (non-combustible dust handling facilities). Some of the common findings were improper house keeping of the combustible dust and the use of compressed air by the facility’s staff to clean the combustible dust which could lead to a dust cloud and result in an explosion if an ignition source is present.
For the complete NEP study in PDF: http://www.osha.gov/dep/combustibledust/NEP-status-report.pdf