PVC-Based Copper Electric Wires under Various Fire Conditions: Toxicity of Fire Effluents

Area of Science:

• Fire Science
• Materials Science
• Environmental Science

Background:

• Ventilation-controlled fires generate toxic fire effluent.
• Understanding combustion gas yields is crucial for fire safety.
• Polyvinyl chloride (PVC)-insulated wires are common in electrical applications.

Purpose of the Study:

• To investigate the impact of ventilation on combustion gas yields from PVC-insulated copper wire.
• To compare these yields with pure polymers (unplasticized PVC and LDPE).
• To assess the contribution of the hyperventilation effect in cable fires.

Main Methods:

• Utilized a steady-state tube furnace to analyze a PVC-insulated copper wire.
• Varied primary airflow (ventilation conditions) during combustion.
• Measured yields of key combustion gases: CO2, CO, hydrocarbons, and HCl.

Main Results:

• PVC-insulated wire showed lower CO2 yields than pure PVC and LDPE.
• CO yields were significantly higher (fourfold) for the insulated wire compared to pure polymers.
• HCl yield was independent of ventilation, with lower values than pure polymer due to copper interaction and flame retardants.

Conclusions:

• The hyperventilation effect's contribution to toxicity appears reduced in fires involving this specific PVC-insulated wire.
• The presence of copper and additives influences combustion product yields, particularly reducing HCl.
• Further research into cable fire toxicity under varying ventilation is warranted.