Scotch tape is on every desk in the country, and it gets used to hang things over lamps, tape cords to walls, and hold Christmas lights in place. Most of those uses are fine. A couple of them aren't.
Scotch tape is combustible but not easily flammable. It is a thin film of cellulose acetate or polypropylene with an acrylic adhesive, and it will melt at a few hundred degrees and burn if it touches a flame. At room temperature it cannot catch fire on its own, and it doesn't give off flammable vapor.
What Scotch Tape Is Made Of
Classic Scotch Magic Tape uses a cellulose acetate film, which is plant-derived but still a plastic. Clear packing and general-purpose tapes use polypropylene. Both films soften around 250 to 300°F and burn at higher temperatures. The adhesive is acrylic, which softens with heat and burns as well. There is no flame-retardant treatment on standard office tape.
Heat Behavior
| Temperature | What happens to Scotch tape |
|---|---|
| Up to ~150°F | Fine; adhesive may get gummy over time |
| 150–250°F | Adhesive fails, tape releases |
| 250–350°F | Film shrinks, curls, and melts |
| Open flame | Burns quickly with a small flame and acrid smoke |
Where It Becomes a Problem
- On lampshades and light fixtures. Incandescent and halogen bulbs run hot enough to melt tape and scorch whatever it was holding. LED bulbs are fine.
- Holding string lights. Older incandescent Christmas lights get warm; tape near the bulbs can soften and drop the strand.
- As electrical tape. Scotch tape is not an insulator rated for electrical use. A warm cord splice will melt it and expose the wire.
- Near candles or a stove. A taped-up note or decoration near a flame is tinder.
Does Scotch Tape Give Off Toxic Fumes?
Burning any plastic produces irritating smoke. Cellulose acetate produces acetic acid vapor (the vinegar smell) and carbon monoxide; polypropylene produces mostly carbon monoxide and soot. A single strip is trivial, but a roll of packing tape in a house fire adds to the smoke load like every other plastic in the room.
Related reading: is Gorilla Tape flammable, is packing tape flammable, and is duct tape flammable.
