The U.S. Department of Occupational Safety and Health Administration (OSHA) has revealed the preliminary top 10 most-frequent workplace safety violations for 2009. The number of top 10 violations has increased almost 30 percent over the same time period in 2008. 
The workplace violations are:
1. Scaffolding (9,093 violations) Scaffold accidents often result from the planking or support giving way, or to the employee slipping or being struck by a falling object.
2. Fall Protection (6,771 violations) Fall protection must be provided at four feet in general industry, five feet in maritime and six feet in construction.
3. Hazard Communication (6,378 violations) Chemical manufacturers and importers are required to evaluate the hazards of the chemicals they produce or import, and prepare labels and safety data sheets to convey the hazard information to their customers.
4. Respiratory Protection (3,803 violations) Respirators protect workers against insufficient oxygen environments, harmful dusts, smokes, gases etc. which may cause may cancer, lung impairment, other diseases or death.
5. Lockout-Tag out (3,321 violations) "Lockout-Tag out” refers to specific practices and procedures to safeguard employees from the unexpected startup of machinery and equipment, or the release of hazardous energy during service or maintenance activities.
6. Electrical (Wiring) (3,079 violations) Many professionals work with electricity directly, including working on overhead lines, cable harnesses, and circuit assemblies.
7. Ladders (3,072 violations) Occupational fatalities caused by falls remain a serious public health problem.
8. Powered Industrial Trucks (2,993 violations) Yearly tens of thousands of injuries related to powered industrial trucks, or forklifts, occur in US workplaces.
9. Electrical (2,556 violations) See No. 6.
10. Machine Guarding (2,364 violations) Any machine part, function, or process that may cause injury must be safeguarded.

Source: The National Safety Council; OSHA