Hazard & protection
| Symbol | Meaning |
|---|---|
| ⚡ (lightning bolt in triangle) | Electric shock hazard |
| △ (exclamation in triangle) | General warning — consult documentation |
| ☢ / radioactive trefoil | Ionizing radiation |
| ☠ (skull and crossbones) | Toxic / deadly |
| 🔥 / flame | Flammable |
| 🧲 | Strong magnetic field (pacemakers, magnetic media) |
| ⚠ High temperature | Hot surface |
| Laser triangle | Laser radiation — class II+ requires warning |
Protection class / grounding
| Symbol | Meaning |
|---|---|
| Double square (⊙ inside ⊡) | Class II — double-insulated, no earth |
| Three horizontal lines ⏚ | Protective earth (PE) / functional ground |
| Triangle with lines at bottom | Chassis ground |
| ⏀ | Earth / ground |
| →│ ← (arrow into vertical bar) | DC voltage |
| ~ (tilde) | AC voltage |
| ⎓ (DC combined with AC bar) | Universal (AC or DC) input |
Certifications
| Mark | Meaning |
|---|---|
| UL | Underwriters Laboratories — US safety |
| CSA | Canadian Standards Association |
| CE | European conformity — self-declared |
| UKCA | UK Conformity Assessed |
| FCC | US radio frequency emission limits |
| PSE | Japan electrical safety |
| RCM | Australia/NZ regulatory compliance |
| RoHS | Restriction of Hazardous Substances (lead-free etc.) |
| WEEE crossed-out bin | Waste electronics — do not bin with household trash |
Notes
- IEC 60417 is the authoritative standard for equipment symbols.
- Always heed the symbol — a lightning bolt without elaboration means capacitors may still be charged after power-off.
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