Five years after a combustible-dust explosion killed 14 workers in Georgia, legislators are again demanding that federal safety regulators set standards for such hazards. The ‘‘Worker Protection against Combustible Dust Explosions and Fires Act of 2013’’ (H.R. 691) would require that OSHA issue a standard for regulating combustible industrial dusts. The bill was introduced Tuesday (Feb. 12) by U.S. Reps. George Miller, D-CA.; John Barrow, D-GA; and Joe Courtney, D-CT.