ResourcesGlossary: testing
Charcoal canister
Short answer
A charcoal canister is a passive short-term radon test device: a small container of activated charcoal that takes up radon from the room air, then is resealed and sent to a laboratory for analysis.
What charcoal canister means
Nebraska's radon program explains the material: activated charcoal detectors use activated carbon, which has a strong affinity for gases and vapors, to absorb radon gas. After exposure they are resealed and returned to a laboratory.
EPA groups charcoal canisters with the passive devices, alongside alpha track detectors, charcoal liquid scintillation detectors and electret ion chambers, and says passive devices are generally inexpensive.
What a charcoal canister costs and how long it sits
Mississippi's health department gives shop prices for the two common passive kits. EPA gives the test lengths. Each row of hours multiplies days by 24.
| Device | Price in a shop | Length of test | Hours |
|---|---|---|---|
| Charcoal canister, EPA's minimum | About $10 to $15 | 2 days | 48 |
| A 7-day charcoal canister | About $10 to $15 | 7 days | 168 |
| Alpha track detector, the shortest long-term test | $30 or so | 91 days | 2,184 |
What it means for your home
Place it where EPA says: in the lowest lived-in level of the home, at least 20 inches above the floor, away from drafts, high heat, high humidity and exterior walls.
Do not let it sit when the test is over. EPA says to reseal the package and send it to the lab specified on the package right away for analysis.
Where to go next
- Which radon test to use. See whether a charcoal kit, a long-term kit or a monitor fits your situation.
- Charcoal test kit or digital radon monitor. The two ways to test at home, side by side.