Mr. Od-1 had just bought a new factory to start producing hydrogen gas for his alternatively fueled vehicles. For safety reasons, there could be no flammable materials in the factory, just steel and concrete. Nothing was even painted. He then hired a company to install a state of the art fire protection system. They had installed hundreds of highly sensitive smoke detectors throughout the factory. Each was linked to a sprinkler control unit so, if triggered, it would immediately open the sprinkler above the fire. Thus, it would save the whole factory from water damage in the event of a fire. After much testing, the system was working perfectly. But when Mr.Od-1 inspected the system, he couldn't believe the colossal mistake they had made. He called the designers of the system in and explained to them, "This is a hydrogen plant. There are no flammable materials allowed in the plant, and employees wear fire proof clothing while in the plant; the only thing that can catch fire is the hydrogen itself." Understanding their mistake, the system designers rebuilt the system.
What had they done wrong?