Milwaukee Journal Sentinel
State OKs Foxconn variance on fire safety requirement
Foxconn Technology Group sought and received a variance for its planned liquid crystal display panel factory from a building code provision that ordinarily requires the roof beams and roof framing of industrial buildings to resist fire for one hour.
The Wisconsin Department of Safety and Professional Services approved the company’s request last month. Foxconn had submitted a consulting engineer’s study concluding that treatment of the roof steel with fire-resistant coatings wasn’t necessary.
Such steps aren’t needed because of the large volume of Foxconn’s display “fab,” the height of the ceilings and the planned use of standard spill-control practices, fire-protection engineers with Jensen Hughes concluded.
Foxconn sought the variance in May. The company said fire-resistant coatings can shed tiny particles and emit gases, causing contamination inside a microelectronics plant.
Production of LCD panels requires a very clean environment. Panels can be ruined even by minute bits of dust in the air.
In analyzing Foxconn’s plans for its display factory in Mount Pleasant, consultant Jensen Hughes Inc., of Baltimore, noted that the ceilings will be at least 38 feet high in the array area — where sheets of thin glass are embed
ded with millions of tiny pixels — and at least 23 feet high in the assembly area.
Because of the heights, only a very large fire could threaten the roof, the engineering report said. By limiting the amount of combustible material in the plant, the potential for such fires can be prevented, the report said.
Managing the amount of material in the building that can burn would yield the equivalent of a one-hour fire-resistance rating for the roof, the report said.
The Jensen Hughes engineers said they used a worst-case scenario, analyzing the integrity of the roof without accounting for the presence of the sprinkler system that is planned, or for other potential intervention to fight a fire.
In its application for the variance, Foxconn said it will use fire-safe plastics to the extent practical and will manage and contain flammable liquids within production tools.
“This approach has successfully been applied sustainably for almost three decades across dozens of semiconductor fabrication facilities, both domestically and internationally,” the company said.
“Performance-based” analyses such as that conducted for Foxconn are becoming more common, said Chris Jelenewicz, technical director at the Society of Fire Protection Engineers.
Properly done, such studies are superior to the prescriptive procedures spelled out in building codes because they can account for the unique characteristics of specific buildings, he said.
“I really believe you can get better fire protection if you’re doing a performance-based approach,” Jelenewicz said.