What residue indicates the presence of gypsum concrete decking during cutting?

When cutting gypsum concrete decking, the residue that is left behind is typically a white powdery substance. This is due to the composition of gypsum, which is a mineral that, when ground into a finer form, tends to produce a white powder. Gypsum concrete is commonly used as a lightweight floor underlayment and is known for both its fire-resistive properties and thermal insulation.

Recognizing this characteristic residue is critical for firefighters, as it can help them identify the materials present in a structure and assess potential hazards during operations. When handling debris or working in environments where these materials are present, understanding what residues to expect can inform risk assessments and operational strategies. The other residues mentioned—black sticky, yellow-green powdery, and grey sticky—do not correspond to the typical residue produced by gypsum concrete and may indicate the presence of different materials, which can have significant implications for safety and handling procedures.