Home Radon Kit: Where to Buy and What You Get
A home radon kit is a self-deployed sampling product that allows a homeowner to test indoor radon concentration without hiring a professional tester. The kit contains a detector, instructions, a deployment log, and a prepaid laboratory return envelope. After exposure for 48 hours to several months depending on the kit type, the homeowner mails the detector to a certified lab for analysis and receives a written result. This guide summarizes EPA and CDPHE guidance current to 2026 and is informational; specific elevated test results should be discussed with a CDPHE-certified mitigation professional. The information below covers where Colorado residents can obtain kits, what is included, and how to choose between short-term and long-term options. The parent radon testing in Colorado pillar covers the broader testing program context.
What is in a typical home radon kit
A standard short-term home radon kit contains five items.
The detector
The actual sampling device. For short-term kits, this is typically a charcoal canister (small metal or plastic cylinder containing activated charcoal that absorbs radon during exposure) or an alpha track detector (small plastic housing with CR-39 film that records alpha particles from radon decay). For long-term kits, alpha track is standard.
Deployment instructions
A printed sheet explaining where to place the detector, how to maintain closed-house conditions during exposure (for short-term tests), the deployment duration, and how to retrieve and seal the detector at the end of the exposure window.
Deployment log
A small form for recording the start date, start time, end date, end time, exposure location, and homeowner contact information. The lab uses this information to calculate the average radon concentration based on the recorded exposure duration.
Prepaid return envelope
A pre-addressed envelope with prepaid postage for mailing the detector back to the laboratory. Most kits use first-class or priority mail for return; some specialty kits include expedited shipping.
Lab analysis fee (included)
The headline kit price typically includes laboratory analysis as part of the cost. Lower-priced unbranded kits sometimes exclude this and require a separate payment when the detector arrives at the lab; this is one of the things to verify before purchasing.
Where Colorado residents get kits
CDPHE subsidized kit program
The Colorado Department of Public Health and Environment runs a subsidized short-term radon test kit program for Colorado residents. Charcoal canister kits with lab analysis included cost $15 through this program (compared with $20 to $30 retail). Residents can request kits through the CDPHE website or pick them up at participating county public health offices. This is generally the most cost-effective option for Colorado residents doing initial screening.
County public health departments
Several Colorado counties periodically distribute free or subsidized radon test kits, often during National Radon Action Month (January) or as part of community wellness events. Boulder County Public Health, Jefferson County Public Health, Tri-County Health (covering Adams, Arapahoe, and Douglas counties), and Denver Environmental Health all run kit distributions on a rotating basis. Quantities are limited; the programs operate first-come, first-served. A look at what radon actually is covers the public-health rationale for these distributions.
Major retailers
Home improvement and hardware retailers stock short-term and long-term radon test kits in their environmental safety or HVAC accessories sections. Common brands include AccuStar, AirChek, FirstAlert, and PRO-Lab. Retail pricing runs $15 to $30 for short-term charcoal kits and $30 to $60 for long-term alpha track kits.
Direct from radon test laboratories
Several specialty radon test labs ship kits directly to homeowners, including AccuStar, RTCA (Radon Testing Corporation of America), and Air Chek. Direct ordering sometimes provides faster lab turnaround and slightly lower per-kit pricing for multi-kit orders.
Through mitigation contractors
CDPHE-certified mitigation contractors often supply test kits to clients before or after mitigation system installation. Post-mitigation kits are usually included in the contractor’s project scope at no additional cost as part of system verification.
Short-term versus long-term kit choice
Two product categories exist, with different use cases.
Short-term kit (48 to 96 hours)
The most common starting product for homeowners doing initial screening. Charcoal canister or short-term alpha track detector. Cost $15 to $30 including lab analysis. Results in 7 to 14 days after lab receipt. Best for: initial screening, post-mitigation verification, real-estate transaction testing.
Long-term kit (90 days to 1 year)
The product for understanding actual residential exposure across seasonal variation. Long-term alpha track detector. Cost $30 to $60 including lab analysis. Results in 7 to 14 days after lab receipt at the end of the deployment period. Best for: confirming borderline short-term results, long-term occupancy assessment, post-mitigation long-term verification.
Front Range homeowners often deploy both: a short-term kit for initial screening, then a long-term kit to confirm or refine the result. Combined cost runs $35 to $75 for both detectors, which is small relative to the mitigation decision the results support. A look at radon test duration covers the timing trade-offs.
How to deploy a home radon kit correctly
The detector physics is well-understood, but the deployment is where homeowners commonly introduce errors that invalidate results.
Where to place it
In the lowest occupied level of the home (the basement if finished, the main level if slab-on-grade), 20 to 72 inches above the floor, away from exterior walls and drafts, away from heat sources and direct sunlight, and away from high-humidity sources (laundry rooms, kitchen counters, bathroom exhausts).
Closed-house compliance (short-term only)
For 12 hours before deployment and during the entire exposure period, keep all exterior doors and windows closed except for normal entry and exit. Do not run whole-house fans, bathroom exhaust fans (except briefly), or attic ventilation. Operate HVAC normally. Long-term tests do not require closed-house compliance because the longer exposure averages across normal occupation.
Recording the timing
Note the exact start date and time on the deployment log. At the end of the exposure period, note the exact end date and time. Lab analysis depends on accurate exposure duration; an extra 12 hours of unrecorded exposure can shift the calculated concentration by 8 to 15 percent.
Sealing and mailing
At the end of exposure, seal the detector immediately according to the kit instructions (charcoal canisters need to be sealed within minutes to prevent further radon absorption). Place in the prepaid envelope and mail within 24 hours.
Reading the result
The lab returns a written result showing the average radon concentration during the exposure period in pCi/L. Interpretation thresholds are the same regardless of kit type. Below 2.0 pCi/L is low risk. 2.0 to 4.0 pCi/L is mid-range with mitigation considered for households with vulnerable residents. 4.0 pCi/L and above is the EPA action level; mitigation is recommended. Above 10.0 pCi/L is substantially elevated. A look at high radon level response covers the mitigation pathway.
What to avoid in home radon kit selection
Three product categories are worth skipping.
Uncredentialed marketplace kits
Online marketplace listings occasionally show short-term radon kits at suspiciously low prices ($5 to $10 per kit). These often exclude lab analysis fees, use non-credentialed labs, or are repackaged consumer monitors rather than actual sampling kits. Always verify the kit uses an NRPP or NRSB credentialed lab before purchasing.
Consumer electronic monitors marketed as kits
Some consumer-grade electronic radon monitors (Airthings Corentium, Ecosense, similar) are useful for ongoing trend monitoring but are not strict equivalents of credentialed sampling kits. They are not the right choice for real-estate transactions or formal radon program submissions. For initial screening, they are acceptable; for actionable decisions, pair them with a credentialed lab-analyzed kit.
Multi-kit bulk packs
Some retailers sell 5-detector or 10-detector packs targeted at landlords, HOAs, or rental property managers. For a single-family homeowner, these are usually not cost-effective; the bulk savings rarely materialize because extra kits expire unused before the homeowner needs them.
How the home radon kit fits into broader radon planning
The home radon kit is the entry point to radon awareness for most Front Range Colorado homeowners. A $15 CDPHE kit identifies whether the home has a radon problem. If the result is elevated, the next step is professional confirmation testing (typically a CRM-based test) and then a mitigation system quote from a CDPHE-certified contractor. If the result is borderline, the next step is a long-term alpha track for seasonal confirmation. If the result is low, the kit becomes baseline documentation that the homeowner can refer back to in 2 to 5 years for re-testing. A look at residential radon exposure covers the broader health context.
Homeowners with kit results, mitigation questions, or interest in connecting with a CDPHE-certified radon professional can reach out through our contact page.
What can go wrong during deployment
Even with clear instructions, several deployment errors occur frequently enough that they are worth flagging explicitly. The first is placing the detector in an unoccupied area like a storage closet or behind furniture, which measures radon in a space nobody breathes in rather than the home’s actual exposure level. The detector should sit in a representative location where family members actually spend time.
The second is allowing the detector to be moved or handled during deployment. A short-term charcoal canister that gets bumped or tipped can release some absorbed radon, lowering the apparent reading. A long-term alpha track that gets relocated mid-deployment averages results from two different locations, which is rarely meaningful. The detector should stay put for the entire exposure period.
The third is mailing the detector back too late. Charcoal canisters in particular continue to absorb radon after the official end of exposure if not sealed promptly. A detector that sits sealed but unmailed for two weeks before getting to the lab produces a slightly inflated reading because the calculation assumes the exposure ended at the recorded end time. Mailing within 24 hours of seal-up is the standard expectation.
Free retest opportunities
For homeowners whose initial kit result is unclear or invalidated by a deployment error, several second-chance options exist. CDPHE will sometimes provide a replacement kit at the subsidized $15 rate if the homeowner explains the deployment issue. County public health departments running periodic kit distributions sometimes offer retest kits for free during follow-up campaigns. Mitigation contractors performing pre-installation testing typically use professional CRM-based testing rather than consumer kits, which provides a fresh result without consumer-kit deployment risks. A look at why visual signs of radon are unreliable covers why testing is the only path forward.
How often to re-test
EPA recommends re-testing every 2 to 5 years even for homes that previously tested below 4.0 pCi/L. Soil-gas dynamics can shift over time as homes settle, sumps and slab penetrations evolve, and surrounding land use changes. A home that tested clean a decade ago may not test the same today. Re-testing every 2 years for homes that previously tested between 2.0 and 4.0 pCi/L and every 5 years for homes that tested below 2.0 pCi/L is a reasonable cadence. After any major foundation repair, basement renovation, or HVAC system change, an immediate re-test is appropriate regardless of prior result.
References
- EPA home radon test kit guidance — U.S. Environmental Protection Agency
- CDPHE Colorado subsidized radon kit program — Colorado Department of Public Health and Environment
- American Lung Association radon test kit resources — American Lung Association
- CDC radon and lung cancer prevention — Centers for Disease Control and Prevention
Radon test kits we recommend
Short-term charcoal kits are the cheapest way to get a first reading; mail the canister to the lab and results come back in days.
| Product | Why | Buy |
|---|---|---|
 AirChek Charcoal Radon Test Kit | Lab fee usually included; EPA short-term protocol. | Amazon — $21.95 |
 First Alert RD1 Radon Test Kit | Widely stocked; 48-hour charcoal test. | Amazon — $17.95 |
| Health Metric Radon Test Kit | Two-pack option for closed-house testing. | Amazon — $17.95 |