🧪 Automotive & battery fluids

serious

Where you meet it: Brake fluid · engine coolant · battery electrolyte · transmission fluid · capacitor electrolyte

What you need to know

Brake fluid (DOT 3/4) is caustic, strips paint, irritates skin and eyes, and is a regulated waste.
Ethylene glycol coolant is acutely toxic and tastes sweet — it kills pets and children. Never leave it in an open pan.
Lithium cell electrolyte (LiPF₆ in carbonates) is flammable and forms hydrogen fluoride on contact with moisture.
Capacitor electrolyte is a skin, eye and respiratory irritant; some formulations smell strongly of ammonia or fish. Flush immediately.
Transmission fluid stays hot for hours after shutdown.

The rule: NEVER pour any of these down a drain or onto the ground. They are all regulated waste streams.

Components this applies to

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 Aerospace Connectors & Backshells Contacts & relays · $25–70/lb Au 0.3–0.8 g/lb complete; ~3.6 g/lb de-populated contactsCu ~80 g/lbBase Backshells: ~0 g Au/lb A X-Ray Film & Spent Fixer Other · $1–4/lb Ag 0.07–0.10 ozt/lb (2.2–3.1 g/lb) medical filmAg 0.15–0.25 ozt/lb industrial NDT filmAg 1–6 g/L in spent fixer B ABS, transmission & body control modules Automotive · $3–8/lb Au 0.010–0.030 g per moduleAg 0.2–1.5 g in BCM relay contactsCu 40–120 g in the ABS pump motorBase 1.5–3 lb aluminium hydraulic block C Backup batteries & Dallas RTC modules ☠ ICs & chips · $50–800/lb Cu ~40 g/lbAu <0.1 g/lb C Hybrid / EV traction inverter ⚡ Automotive · $8–20/lb Cu 3–8 kg per inverterAg 0.5–3 g sinter per power stageAu 0.02–0.08 g on gate-driver boardsBase 5–15 kg aluminium housing 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 Airbag inflators & undeployed modules ☠ Automotive · $0–0/lb Base none worth recovering D 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 MAF, MAP, knock, crank & cam sensors Automotive · $1–4/lb Pt 0.5–2 mg per hot-wire MAFAu 0.003–0.010 g per MAF boardAg 10–40 mg thick-film paste on MAP hybridsNd magnets in Hall-type crank/cam sensors D Oxygen / lambda sensors Automotive · $2–5/lb Pt 13 mg per sensor (≈0.05 g/lb)Cu 8–20 g in the leadBase steel body D Thermal Printheads Other · $200–900/lb Au 0.002–0.02 g per head ≈ 0.06 g/lbBase Ru as RuO2 glazeBase alumina substrate + Al heatsink bar D

All 25 hazards →