A contractor crew dismantling chemical piping at a memory-chip plant in Kaohsiung, Taiwan, China, found that a line can still be live after the process has stopped. The crew was sprayed with a waste stream of hydrofluoric acid and nitric acid on 2 October 2026. Four workers were treated for burns to the face, hands, torso, forearms and lower body, and the affected section was shut while labour inspectors opened an investigation. Whether the line had been fully depressurised and isolated before it was opened is among the points still under investigation. Hydrofluoric acid is not the strongest acid in a fabrication plant, but it is among the most deceptive.
A Weak Acid With a Deep Reach
HF sits low in conventional acid rankings and is often filed with mild cleaning chemicals. Its danger is transport, not surface corrosion. The fluoride ion crosses intact skin and binds calcium and magnesium in tissue and blood, producing hypocalcaemia, tissue necrosis and, in serious cases, cardiac effects. Symptoms can arrive hours after contact, and damage under the skin can be worse than the visible burn. Nitrile, the default glove in most electronics plants, is not a safe answer for concentrated HF or an HF-nitric blend; breakthrough against the mixture can be far faster than against either component alone. Butyl rubber, neoprene and multilayer laminates are the practical baseline, with fluoropolymer laminates reserved for the most aggressive streams and for tasks where splash volume defines the hazard.
Maintenance Crews Are Where the Exposure Lives
Staff who handle acids in a closed loop rarely meet the worst exposure. Risk concentrates in turnarounds, pipe work, filter changes and waste-line repairs, often done by contractors working to a permit. A South Korean labour ministry review published on 20 September 2026, covering 27 semiconductor manufacturing sites, supports that reading. Inspectors recorded hundreds of violations and traced a fluorine gas leak and fire earlier in the year to skipped pre-work checks and gas work started without the required permit. Missing pipe caps, absent gas detectors and unmarked confined spaces were also cited. The exposure is a procedure failure first and an equipment failure second.
Specifying Gloves and Boots for Mixed Acid Service
Three rules follow. First, gauntlet length: a forearm-length cuff worn under the suit sleeve stops the run-down that otherwise reaches wrists and forearms. Second, double gloving, with a thin liner for dexterity and a heavier outer shell that resists snagging on flanges and pipe ends. Third, footwear. Mixed acid ends up on floors and rinse decks, and the incident above included lower-body burns. Chemical-resistant overboots with published permeation data, slip resistance and anti-static compliance for solvent and gas areas are the minimum, and they must survive a rinse-and-dry cycle, since residue carried out of the work zone is its own hazard. Calcium gluconate gel must be within reach, and a glove that cannot be stripped off quickly will delay it. Aged stock is a live risk too: a chemical park drill in Inner Mongolia on 4 September 2026 simulated an HF tanker unloading failure in which the escort's protective equipment had aged.
What Buyers Should Ask For
Ask suppliers for permeation and degradation data against the specific HF concentration and against HF-nitric blends, not a generic acid-resistance claim. Confirm a glove or boot family meets chemical, mechanical and anti-static requirements in one item. Set shelf-life limits, storage conditions and an in-service inspection routine. Stock a contractor sizing range, and pair every order with first-aid training and marked change-out points at the line boundary.
