Steel Pickling - HCl Process Facilities and Hydrochloric Acid Regeneration Plants: National Emission Standards for Hazardous Air Pollutants

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Rule Summary

This rule sets national emission standards for hazardous air pollutants (NESHAP) for hydrochloric acid (HCI) process steel pickling facilities and hydrochloric acid regeneration plants pursuant to section 112 of the Clean Air Act (Act).

Pickling is a process in which an acid solution is used to remove oxide scale from steel strip, rod, wire, tubing, and discreet shapes. Oxide scale forms on the surface of the steel when steel cools from a molten state. The steel pickling facilities that are affected by this rule use a solution of hydrochloric acid (HCl) to remove the oxide scale.

This process emits HCI, a hazardous air pollutant (HAP). Chronic exposure to HCl has been reported to cause gastritis, chronic bronchitis, dermatitis, and photosensitization. Acute inhalation exposure to HCl may cause hoarseness, inflammation and ulceration of the respiratory tract, chest pain, and pulmonary edema. Hydrochloric acid regeneration plants also emit chlorine (Cl2), which is also a HAP. Acute exposure to high levels of Cl2 results in chest pain, vomiting, toxic pneumonitis, pulmonary edema, and death. At lower levels, Cl2 is a potent irritant to the eyes, the upper respiratory tract, and lungs.

This rule provides public health protection by requiring new or existing pickling lines that use hydrochloric acid as the primary pickling solution, hydrochloric acid regeneration plants, and acid storage tanks to meet emission standards reflecting application of the maximum achievable control technology (MACT). EPA expects implementation of this rule to reduce HAP emissions by more than 2,200 megagrams per year (Mg/yr) (2,500 tons per year (tpy) from current levels.