Rust / section loss
Corrosion silently thins members; inspection intervals matter more than brochure yield.
Safety here is encyclopedia, not a workplace assessment. Name the agent: dust, isocyanate, fibre, fume, moisture, fire.
Fire class A1 as construction steel is reaction language unless an assembly test is cited.
危険
Weld fumes
Hexavalent chromium in stainless fumes; manganese in some wires.
Sharp edges
Sheared plate and swarf cut; PPE is not optional on a fab floor.
Hot work
Sparks ignite nearby combustibles — a site fire class problem, not a steel chemistry one.
Noise / vibration
Rolling mills and grinders: hearing protection is part of the process envelope.
火災等級
Reaction
A1 non-combustible as a metal.
Resistance
Unprotected members fail by yielding, not by burning.
Coatings
Intumescents expand to a char foam; thickness maps to R-rating.
Compartments
鋼 decks still need fire-rated floors and seals around penetrations.
環境
CO₂
BF–BOF is carbon-intensive; EAF scrap and DRI-H2 change the ledger.
Recycling
Magnetic separation makes steel the most recycled structural metal.
Slag
BFS used in cement; still a by-product that needs a market.
Water
Pickling acids and mill scale must be treated, not dumped.
取扱い
Store dry
Mill scale plus rain starts flash rust on uncoated stock.
Weld procedure
Follow WPS: preheat, interpass, hydrogen bake-out on thick high-CE plate.
Lifting
Sharp plate edges slice slings; use edge protectors.
Cut fume
Laser/plasma cutting of coated steels needs extraction.
Codes move. Recheck KS, JIS, EN, NFPA and IBC editions for the job’s jurisdiction.