The Occupational Safety and Health Administration (OSHA) Form 300A, Summary of Work-Related Injuries and Illnesses, must be posted in a conspicuous location by Feb. 1 of each year and left up for viewing until April 30. The summary lists only numbers of affected employees by category.

Companies that operate in more than one location must complete a separate summary for each of them.

At the same time, covered employers are required to complete the OSHA Form 300, Log of Work-Related Injuries and Illnesses, which is a more detailed document specifying names of ill and injured employees. This form should not be posted in any location visible to anyone not employed by the company and, if posted, must have the employees' names redacted for privacy purposes. In short, posting of the Form 300A is sufficient, and optional posting of the Form 300 can create headaches.

The OSHA Form 300 must be retained for five years.

Employers with ten or fewer employees and employers in certain industry groups are normally exempt from federal OSHA injury and illness recordkeeping and posting requirements. A complete list of exempt industries in the retail, services, finance and real estate sectors is posted on the OSHA Web site.