Definitions. In this regulation, the following terms have the meanings indicated. Terms Defined. “Controlled air spray system” means a method of spraying a coating that has an enhanced transfer efficiency such as a high-volume, low-pressure (HVLP) or low-volume, low-pressure (LVLP) spray system that utilizes an air pressure between 0.1 and 10.0 psig in the spray gun. “Dip-coating operation” means a process in which structural steel is coated by dipping into stationary tanks filled with liquid coatings. “Protective coating” means a primer mixed with mineral spirits or other solvents, that is used in a coating operation for corrosion protection. “Structural steel-coating operation” means a facility that applies a coating to fabricated steel components such as welded steel joists, steel beams, and columns used to assemble buildings and other large structures. Applicability. This regulation applies to a person who owns or operates a structural steel-coating operation that has a total potential to emit VOCs of 25 tons or more per year or actual emissions of 20 pounds or more in any 1 day. Coating Requirements. Except as provided in §C(2) of this regulation, a person who owns or operates a structural steel-coating operation subject to this regulation may not use any protective coating that exceeds: 3.9 pounds of VOC per gallon, as applied in a dip-coating operation; or 3.5 pounds of VOC per gallon, as applied by means other than a dip-coating operation. A person subject to this regulation may apply a coating that exceeds the VOC content established in §C(1) of this regulation if: The VOC content of the coating does not exceed a standard in §C(1) of this regulation by more than 20 percent; and The coatings exceeding a standard in §C(1) of this regulation are used only during the period from November 1 of any year through March 31 of the following year. Except for dip-coating operations, a person subject to this regulation shall apply coatings under a controlled air spray system or other system approved by the Department. Cleanup Requirements. A person subject to this regulation shall take reasonable precautions to minimize the release of VOC into the atmosphere including: Minimizing the quantity of VOC used to clean lines or equipment by using detergents, high-pressure water, or low VOC cleaning materials; Using enclosed containers or VOC recycling equipment to clean spray gun equipment; Storing all waste materials containing VOC, including cloth and paper, in closed containers; and Maintaining lids on any VOC-bearing materials when not in use.