🌡 Mercury

serious

Where you meet it: Tilt switches (thermostats, old appliances, vending and pinball) · mercury-wetted relays · mercury-vapour rectifier tubes (866A, 83, 3B28) · CCFL backlight tubes in pre-2012 LCDs · fluorescent lamps

What you need to know

Do not break CCFL tubes. Pre-~2012 LCD panels are CCFL-backlit; LED-backlit panels are mercury-free. When in doubt, don't crack the panel.
Mercury vapour is odourless and neurotoxic. Room-temperature evaporation from a spill is enough to matter in an enclosed space.
A tilt switch shows a visible silvery bead in a small glass ampoule.
Mercury-containing devices are universal waste in the US and must go to a proper handler.

The rule: NEVER vacuum a mercury spill — it aerosolises it. Use a mercury spill kit or sulphur powder, or call your local hazmat line.

Components this applies to

Laboratory Platinum Ware Other · $20000–32000/lb Pt ~454 g/lb — it is solid metalAu 5% in Pt-5%Au XRF fusion cruciblesBase Rh 5–10% in Pt-Rh crucibles S Noble Thermocouple Wire (Type R/S/B) Other · $18000–31000/lb Pt ~410 g per lb of bare noble wireBase Rh 6–30% of one legBase Type K/J/T/E/N: zero PGM S Silver-Oxide Button Cells Other · $40–120/lb Ag ~30–35% by weight ≈ 150 g/lbBase Zn anode ~25%Base LR/AG alkaline S Sterling & Silver-Plated Flatware Other · $700–2000/lb Ag 92.5% ≈ 420 g/lb sterlingAg hollow-handle knives: only 8–20 g per pieceAg silver plate: ~0.1–0.5 g per teaspoon S Thermostats, Snap Discs & Limit Switches Contacts & relays · $25–120/lb Ag 0.4–1.6 g/lb as whole discs; 408–431 g/lb as harvested contactsBase bimetal steel discBase Hg ~3–4 g per bulb thermostat ampoule B Industrial Control Boards (PLC/DCS/SCADA) Boards · $3–12/lb Au 0.05–0.20 g/lb typical I/O; 0.25–0.60 g/lb CPU and backplanes; 0.6–1.5 g/lb 1970s–80s ceramic-DIP DCSAg 1–8 g per relay moduleCu ~113 g/lb C Instrument clusters & head units Automotive · $3–12/lb Au 0.008–0.100 g per unitAg 0.2–0.6 g in a premium head unitPd 0.02–0.06 g in a premium head unitCu 20–500 g C Klystrons & Travelling-Wave Tubes RF, power & vintage · $3–40/lb Cu ~250 g/lb (0.35–0.75 lb Cu per lb of tube)Au ~0.5–4 g per tubeAg 2–30 g per tube C Semiconductor Wafers & Fab Tooling Other · $20–200/lb Au 0.0045 g/lb generic research-fab wafer scrapAu 7.4 g/lb for 1 µm gold-backed wafersBase quartz and SiC boats: zero metal C Vacuum tubes RF, power & vintage · $5–20/lb Au 0.1–0.5 g/lb (gold-pin types)Ag traceBase nickel plates C Xenon HID ballasts & LED drivers Automotive · $2–6/lb Au 0.003–0.015 g per ballastCu 30–90 g in the HV transformer and inductorsAg trace in thick-film and solder C LCD Panels (ITO / CCFL vs LED) Other · $0–8/lb Base Indium ~0.4–0.8 g/m² of ITO layerAu 0.01–0.08 g per panel in COF tape bumpsCu ~17 g/lb D Nixie Tubes, VFDs & Dekatrons Other · $150–900/lb Base nickel cathodesBase tungsten filament (µg) in VFDsBase total metal value $0.02–0.15 per tube D Platinum RTD Probes (Pt100/Pt1000) Other · $45–200/lb Pt ~30–80 mg per lb of complete probesBase 0.9–0.99 lb/lb 316SS or Inconel sheathPt SPRT: 15–30 g per unit D Reed Switches & Reed Relays Contacts & relays · $5–20/lb Base Ru ~50–80 µg per switchBase Rh ~0.2–0.5 mg per switchCu ~40 g/lb D

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