Pickling paste is used for cleaning stainless steel weld seam heat marks. It is a mixture of hydrofluoric acid (HF) and nitric acid (HNO3) with surfactants and inhibitors. The substance is corrosive, toxic, and irritant. Air respirator and half mask air filter covering nose and mouth are mandatory before handling the pickling paste. This is a case report of a 28-year-old male complaining of sudden onset dyspnea at rest after accidental inhalation of pickling paste fumes. The patient developed acute lung injury and subsequently acute respiratory distress syndrome and was treated with noninvasive ventilation, steroids, and other supportive treatment.