Polyurethane Foam and Conveyor Fire Reignites Overnight
Winnsboro, South Carolina
Facility and Industry Description
The incident occurred at the MLILY USA mattress factory in Winnsboro, South Carolina, an approximately 650,000-square-foot industrial manufacturing plant. Facilities of this type produce flexible polyurethane foam blocks, bedding, and proprietary memory foam mattresses. These operations manage a complex mix of manufacturing processes, conveyors, work-in-process materials, and significant combustible polyurethane foam storage.
Incident Summary
On August 16, 2026, at 9:00 a.m., a fire alarm sounded in response to a fire that ignited along a production conveyor carrying polyurethane foam products. Emergency responders from multiple agencies arrived and initially confined the fire to a limited area, bringing it under control by 6:00 p.m..
Around 11:30 p.m., the fire reignited and spread through much of the plant. The scale of the reignition prompted the activation of a statewide mobilization program, bringing nearly 150 firefighters and extensive apparatus to battle the blaze through the morning of August 17. The building was ultimately declared a total loss. No injuries were reported among factory employees.
Speculation on Potential Causes
Initial Ignition: Mechanical friction or an overheated conveyor bearing could have provided the activation energy to ignite polyurethane foam dust and scrap along the transfer line.
Reignition Factors: The thermal insulation properties of cellular foam functioned as a thermal barrier, shielding deep smoldering core material within stored foam bun stock from initial suppression streams. This shielding effect allowed hot spots to maintain their thermal energy and reignite once oxygen levels in the surrounding environment normalized.
Application of Industry Standards
NFPA 13 (Standard for the Installation of Sprinkler Systems) & NFPA 1 (Fire Code: Cellular Plastics Storage): These standards specify high-density ceiling and in-rack sprinkler discharge criteria designed to control deep-seated combustion in expanded plastics. Adhering to these criteria provides the water application density necessary to penetrate dense foam storage configurations, overcoming the material's thermal resistance to cool the smoldering cores.
NFPA 654 (Standard for the Prevention of Fire and Dust Explosions from the Manufacturing, Processing, and Handling of Combustible Particulate Solids): This standard outlines requirements for thermal monitoring on conveyor bearings, regular housekeeping for foam particulate, and spark detection interlocks. Implementing these physical engineering controls mitigates the risk of initial ignition by identifying overheated components before they provide the heat required to ignite accumulated dust or scrap along transfer lines.
Top Sources of Information
Risk Logic: "Mattress Factory Fire Protection: Lessons from Winnsboro"
Daily Dispatch: "First responders contain fire at Winnsboro factory"
WLTX: "Fairfield County mattress plant a 'total loss' after fire repeatedly reignites