Acid exhaust is a dedicated ventilation system specifically designed to handle corrosive acidic fumes from semiconductor processes. Purpose: Safely capture and remove corrosive acid vapors from wet benches, etch tools, and chemical stations without damaging ductwork. Corrosive-resistant materials: PVDF, polypropylene, FRP (fiberglass reinforced plastic), or PFA-lined ductwork. Metal would corrode rapidly. Sources: Wet etch baths (HF, HNO3, H2SO4), cleaning chemicals, CVD exhaust with corrosive byproducts. Separation: Kept separate from other exhaust systems (solvent, general, heat) to prevent reactions and allow appropriate treatment. Scrubbing: Routes to acid scrubber before environmental release. Neutralization with caustic solution. Velocity: Maintained at sufficient velocity to prevent condensation and corrosion inside ducts. Drainage: Ductwork sloped with drains for condensate collection. Detection: Exhaust monitors for abnormal concentrations. Maintenance: Regular inspection for corrosion, leaks, build-up. Corrosion-resistant fasteners and seals. Fire codes: Specific requirements for acid exhaust systems in building codes and NFPA standards.