Safety Topic · 320 articles
TL;DR — The numbers that define cryogenic risk One litre of liquid nitrogen becomes roughly 700 litres of gas as it warms — enough to silently strip the oxygen out of a room. Oxygen below 19.5% by volume is an…
TL;DR Move first, treat second — get the person clear of the cryogen source before touching the injury, because cold vapour and pooled liquid keep causing damage. Rewarm slowly with lukewarm water (around 40–42°C / 104–108°F) — never hot water,…
TL;DR — Key Numbers −196 °C (−320 °F): the boiling point of liquid nitrogen, cold enough to freeze skin tissue on contact (Compressed Gas Association). ~700 to 1: one volume of liquid nitrogen expands to roughly 700 volumes of gas…
TL;DR If the gear is being switched, racked, or isolated, treat it as the highest-risk moment — HSE's HSG230 (UK, 2015) identifies operation, not standing service, as when switchgear is most likely to fail. If you operate switchgear, your PPE…
TL;DR Falls from height killed 35 workers in Great Britain in 2024/25 — the single largest fatal category, around 28% of all worker deaths (HSE, 2025). Low-rise timber work is not low-risk. OSHA requires fall protection at 6 ft (1.8…
TL;DR Map hazards by class, not by site type. Atmospheric, chemical, biological, physical, and confined-space hazards run across both treatment plants and the distribution network. Treat confined space as the top killer. It concentrates gas, engulfment, and chemical hazards in…
TL;DR — Myth vs Reality Myth: An old oil-filled transformer is "just oil" with a normal fire risk. Reality: pre-ban units may hold PCB-based askarel fluid that is nonflammable but releases highly toxic furans and dioxins when it burns. Myth:…
TL;DR Two instruments, every check. A skin check pairs a short symptom questionnaire with a visual inspection of exposed skin — neither alone catches early cases reliably. Compare to the worker, not a textbook. Every inspection is read against that…
TL;DR Five tiers, one pipeline — Baseline questionnaire, annual screening, clinical assessment, physician diagnosis, then optional specialist testing; each step escalates only when symptoms appear. The trigger is the action value — Surveillance becomes a legal duty above 2.5 m/s²…
TL;DR — The Numbers That Govern Setup 85 dBA action level (US): OSHA requires an audiometric testing program once an 8-hour TWA reaches 85 dBA under 29 CFR 1910.95(g) — the trigger sits at the action level, not the 90…
TL;DR Three exposure limits, three numbers: Respirable crystalline silica is capped at 50 µg/m³ in the US (OSHA, 2016), 0.1 mg/m³ in the UK and EU (HSE EH40 / EU Directive, 2017), and a stricter 25 µg/m³ health-based guideline (ACGIH…
TL;DR Treat the risk assessment as a living document, not a licensing formality. It must be reviewed every time the build, weather, or crowd profile changes — not filed after sign-off. The legal duty stays with the organiser. A Safety…
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