Which toxic products of combustion are commonly produced during combustion as highlighted in the material?

• A. water vapor and soot
• B. carbon monoxide and hydrogen cyanide
• C. carbon monoxide and sulfur dioxide
• D. nitrogen oxide and ozone

Answer: (B)

Toxic products of combustion often highlighted for safety are carbon monoxide and hydrogen cyanide. Carbon monoxide is a colorless, odorless gas that binds strongly to hemoglobin, forming carboxyhemoglobin and preventing oxygen from being carried to tissues, which can cause rapid hypoxia. Hydrogen cyanide is produced when nitrogen-containing materials burn and it blocks cellular respiration by inhibiting an essential enzyme in mitochondria, effectively stopping cells from using oxygen. These two gases are commonly emphasized because they pose immediate, life-threatening risks to both occupants and responders in fire environments. Other options mix in substances like water vapor (harmless in itself) or soot (particulate matter) or name pollutants like sulfur dioxide and NOx/ozone, which are toxic but not the typical pair described in the material for this context.