Chemical labs, food processing plants, marine engine rooms, pharmaceutical cleanrooms, and offshore platforms share one characteristic: the environment actively attacks carbon steel. Chloride ions, acidic vapors, washdown chemicals (NaOH, quaternary ammonium), and humidity cycles penetrate zinc within weeks.
Failure progression: zinc white rust (zinc oxide) forms -> base metal corrosion at edges/scratches -> raceway pitting -> drag increases 300-500% -> operators force drawers -> rails bend -> complete failure. In food processing, this completes in 3-6 months. In pharma cleanrooms, even white rust particles contaminate the controlled environment.
Cost of failure exceeds replacement hardware: production downtime, contamination investigations, regulatory findings, and in food/pharma, potential recalls. This is why stainless - despite 2-3x premium - is economically rational.