Heat transfer from hot surfaces to dust deposit trapped over them represents a common industrial hazard, especially in facilities that handle or process combustibles in the range of 10 μm to 400 μm. Fugitive dust is usually trapped in the surfaces of process and handling machinery, switch-boards, electrical conduits and several other hard to reach areas. If these surfaces are above a minimum threshold temperature, the dust deposited over them can undergo spontaneous ignition. This provides an ignition site for nearby combustibles. This ignition behavior is systematically analyzed in this study, using a validated two-dimensional numerical model implemented using FLUENT. The simulations of ignition of coal dust layers deposited over a flat hot plate and coal dust trapped between two hot plates those form the shape of a wedge having different angles have been carried out. Results show that dust deposited at acute angled wedges pose a significantly greater hazard compared to wider angles or a flat plate case. Implications to existing safety standards espoused by the industry are discussed and improvements to industry-standard test methods are suggested.