Combustible dusts are fine particles that present an explosion hazard when suspended in air under certain conditions. A dust explosion can cause catastrophic loss of life, injuries, and destruction of buildings. The U.S. Chemical Safety and Hazard Investigation Board (CSB) identified 281 combustible dust incidents between 1980 and 2005 that led to the deaths of 119 workers, injured 718, and extensively damaged numerous industrial facilities. More recently, additional incidents have occurred. On February 7, 2008, a sugar dust explosion and subsequent fire at a sugar refinery in Port Wentworth, Georgia, caused 14 deaths and left many other workers seriously injured with severe burns. In many of these incidents, workers and managers were unaware of the potential for dust explosions, or failed to recognize the serious nature of dust explosion hazards. The CSB reviewed Material Safety Data Sheets (MSDS) of 140 known substances that produce combustible dusts and found poor or inadequate transmittal of information regarding potential dust hazards; 41% of the MSDSs reviewed by the CSB did not warn users about potential explosion hazards. Of the remaining 59% of MSDSs sampled, most of the information was either not stated in a place or manner clearly recognized by workers, or was not specific to hazards related to combustible dusts (CSB, 2006). The Hazard Communication Standard comprehensively addresses the evaluation of the potential hazards of chemicals and the communication of hazard information to workers (29 CFR 1910. 1200(a)(2)). It is a performance-oriented standard that applies to any chemical known to be present in the workplace in such a manner that workers may be exposed under normal conditions of use or in a foreseeable emergency (29 CFR 1910.1200 (b)(2)). Regarding dusts and other particulates, a hazard evaluation must be conducted taking into consideration all discernible hazards, including that of explosibility. It is incumbent upon manufacturers and importers to provide information on the potential for and control of combustible dusts. This document is intended to help manufacturers and importers of chemicals recognize the potential for dust explosions and to identify appropriate protective measures as part of their hazard determination under the Hazard Communication Standard (HCS). This evaluation of hazards ensures that downstream employers and workers are provided MSDSs with complete and accurate information regarding dust explosion hazards, appropriate information is included on labels, and that workers are properly trained regarding workplace combustible dust hazards. Adequate communication of hazard information is essential to ensuring that both employers and workers are aware of dust related hazards and measures that can be taken to prevent dust explosions.