Corded vs. Cordless Tool Safety
Battery tools have taken over many jobsites. They get rid of tripping over cords and shock from damaged cords, but they bring their own risks: lithium-ion battery fires, and tools that are always “live” while the battery is in.
- All trades
- Homeowners
Side by side
| Corded | Cordless | |
|---|---|---|
| Shock | Damaged cords, missing ground pins and wet conditions can shock you | Very low shock risk from the tool itself |
| Trips | Cords across walkways and stairs | None from the tool |
| Fire | Overheated or overloaded cords | Damaged, overheated or poorly charged batteries can catch fire or explode |
| Unexpected start | When plugged in | Whenever the battery is in |
| Required protection | GFCIs on construction sites; grounded or double-insulated tools | Maker’s batteries and chargers |
Corded tools
- On construction sites, plug into GFCI-protected outlets or use a portable GFCI. See GFCIs.
- Use grounded (3-prong) or double-insulated tools. Never cut off the ground pin.
- Inspect cords for cuts, crushed spots and missing strain relief. Tag out damaged cords and tools.
- Don’t carry tools by the cord or yank the cord to unplug.
- Use extension cords rated for the tool’s load and for outdoor or hard use. See Extension Cords.
Cordless tools and batteries
- Remove the battery before changing blades, bits or discs, clearing jams, or making adjustments.
- Use the maker’s batteries and chargers; knock-off batteries may lack protection circuits.
- Charge on a non-flammable surface, away from combustibles, and not unattended overnight in a truck or trailer.
- Don’t charge hot or frozen batteries; let them come to room temperature first.
- Store batteries with terminal covers, away from nails, screws and coins that can short them.
- Retire damaged batteries: dropped hard, cracked, swollen, leaking, very hot or smelling odd. Recycle them properly; don’t throw them in the trash.
Battery fires are hard to put out. A lithium-ion battery in “thermal runaway” can reignite and give off toxic smoke. Move away, call 911 for anything beyond a small fire, and use lots of water or the extinguisher your site specifies. See Battery Safety.
Both kinds
- Guards in place and working
- Switch works and returns to off
- Right PPE for the tool: eyes, ears, hands, and a respirator for dusty work
- Tool off before plugging in or inserting the battery
- Damaged tools tagged “Do Not Use” and removed
Standards & references
- 29 CFR 1926.404(b)(1): GFCIs and assured grounding on construction sites
- 29 CFR 1926.302: Power-operated hand tools
- See also: Power Tool Basics
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