Testing your home for radon is simple, inexpensive, and the only way to know if you're at risk. Here's everything you need to know to do it right.
A charcoal canister or electret ion chamber is placed in the lowest livable area of your home for 2–7 days. You then mail it to a certified lab. Results arrive within a week.
| Short-Term | Long-Term | Professional | |
|---|---|---|---|
| Duration | 2–7 days | 90 days–1 year | 48–96 hours |
| Cost | $15–$30 | $20–$40 | $100–$300 |
| Accuracy | Screening | Most Accurate | Certified |
| Real Estate Use | Yes (confirm w/ 2nd test) | No (too slow) | Yes (preferred) |
| DIY Friendly | Yes | Yes | No |
| Lab Required | Yes (mail-in) | Yes (mail-in) | Contractor handles |
Available in-store and online. Look for First Alert or Kidde brand kits.
VisitIn-store and online. Same major brands as Home Depot.
VisitWidest selection including long-term alpha track detectors. Verify lab certification.
VisitAvailable at most locations. Call ahead to confirm stock.
VisitMany state programs offer subsidized test kits. Check your state radon office.
VisitOrder directly from certified labs. Often the most affordable option.
VisitAlways verify lab certification. When purchasing a test kit, confirm the included lab is certified by the National Radon Proficiency Program (NRPP) or the National Radon Safety Board (NRSB). Uncertified labs may produce inaccurate results.
No immediate action needed. Consider a long-term test to confirm.
EPA recommends considering mitigation. Retest to confirm.
EPA recommends mitigation. Contact a certified contractor.
Mitigate as soon as possible. Avoid spending extended time in affected areas.
Take immediate action. Limit time in affected areas until mitigated.
Place the test in the lowest livable area of your home.
Don't place the test in a kitchen, bathroom, or laundry room — humidity skews results.
Keep windows and doors closed for 12 hours before and during a short-term test.
Don't place the test near a window, door, HVAC vent, or exterior wall.
Place the test at least 20 inches above the floor and away from the ceiling.
Don't run fans, air purifiers, or whole-house ventilation during a short-term test.
If your result is 4+ pCi/L, confirm with a second test before hiring a contractor.
Don't test during severe storms or high winds — pressure changes affect results.
A $15 test kit from your local hardware store is all it takes. You now know exactly how to use it.