What type of physical evidence may include hazardous materials?

Combustion residues are a type of physical evidence that may include hazardous materials. In fire investigations, combustion residues refer to the byproducts released during the burning process, which can consist of toxic substances, including soot, smoke, and various harmful chemicals. These residues not only contribute to the understanding of the fire's origins and development but can also present significant health hazards.

For example, if a fire involves certain types of materials, such as plastics or chemicals, the resulting combustion residues may be hazardous when inhaled or contacted. Identifying and analyzing these residues can provide crucial insights into how the fire started and whether it was a result of intentional acts like arson or accidental causes.

In contrast, evidence of arson primarily pertains to circumstantial indicators that suggest a fire was deliberately set, rather than the hazardous materials themselves. Injuries to victims typically focus on the effects of the fire on people and do not inherently involve hazardous materials as direct evidence. Electrical systems may provide insights into electrical fires or faults, but they do not inherently represent physical evidence of hazardous materials in the same way that combustion residues do.