A practical guide to storing hydrochloric and sulphuric acid on industrial sites — segregation, bunding, PPE and the spill response steps that actually matter.
Acid incidents are rarely caused by exotic failures. They are caused by an incompatible chemical stored on the wrong shelf, a bund that was never sized correctly, or an operator who did not know where the eyewash station was.
Segregation is the first control
Acids must be stored away from alkalis, oxidisers, cyanides and sulphides. Mixing hydrochloric acid with sodium hypochlorite releases chlorine gas; contact with cyanide salts releases hydrogen cyanide. Physical separation by a wall or a dedicated store is the only reliable control. Adjacent shelving in the same bund does not qualify.
Size the bund properly
A bund should hold at least 110% of the largest single container it serves, or 25% of the total stored volume, whichever is greater. It must be constructed from acid-resistant material — plain concrete degrades under sulphuric acid — and must have no drain to storm water.
Ventilation and temperature
Concentrated hydrochloric acid gives off corrosive fumes that will attack nearby steelwork and electrical fittings. Store in a well-ventilated area, ideally with local extraction, and keep out of direct sunlight. Sulphuric acid generates significant heat when it contacts water, so keep the store dry.
PPE that is actually available
Chemical splash goggles, a face shield, acid-resistant gloves (neoprene or butyl, not latex) and an apron should be stored at the point of use, not in a supervisor's office. An emergency shower and eyewash must be within ten seconds' walk and tested weekly.
Decanting: always acid to water
When diluting, add acid to water slowly with stirring — never the reverse. Adding water to concentrated sulphuric acid causes violent, localised boiling that ejects acid from the vessel.
Spill response, in order
Evacuate and isolate the area. Do not use water on a concentrated acid spill — it generates heat and spreads the material. Contain with an inert absorbent such as vermiculite or dry sand, then neutralise carefully with soda ash or lime. Collect the residue for licensed disposal. Only trained personnel in full PPE should approach.
Documentation
Keep the current Safety Data Sheet at the store, not in a filing cabinet. Section 7 covers handling and storage, section 8 covers exposure controls and PPE. Train new operators against it and record the training.
