I just received my new copy of NFPA 654 Combustible Dust Standard 2013 edition. The key sections related to FR clothing are:

Section “Personnel exposed to a dust flash fire hazard shall be protected in accordance with 11.2.2.”

Section 11.2.2 “Operating and maintenance procedures shall address personal protective equipment (PPE), including flame-resistant garments, in accordance with the workplace hazard assessment required in NFPA 2113…”

Appendix A11.2.2 “Where a dust explosion hazard or dust flash fire hazard exists, flame-resistant garments provide a measure of protection for exposed personnel.”

Click here if you would like more information about the combustible dust hazard.