What is the difference between a short-term and long-term radon test?

A short-term test uses an activated-charcoal kit left in the home for two to 90 days and gives a fast snapshot. A long-term test uses an alpha-track detector for 90 days or more and captures a better annual average, because radon swings with the seasons and the weather. Short-term is common for quick screening and home sales; long-term tells you how the house behaves year round.

Is a 48-hour radon test accurate enough?

A a minimum 48-hour test under closed-building conditions is the recognized short-term protocol and is what most home sales rely on. It is accurate for that window, but it is a snapshot. The EPA recommends a follow-up test if a short-term result is at or above 4.0 pCi/L, and a long-term test if you want a truer year-round average before deciding on a system.

Where can I buy a radon test kit in Wisconsin?

Wisconsin runs 17 regional Radon Information Centers that serve all 72 counties and sell low-cost kits, typically about $15 including lab analysis. You can find your center through Wisconsin DHS or call the national radon hotline at 1-888-LOW-RADON (1-888-569-7236). Hardware stores and online retailers also sell kits, usually about $15 to $40.

What radon level means I should mitigate?

The EPA action level is 4.0 pCi/L. At or above that number, the EPA recommends confirming with a follow-up test and then reducing the level with a mitigation system. Between 2 to 4 pCi/L you may still choose to fix, since there is no known safe level. A radon professional can help you weigh the reading and the next step.

When is the best time of year to test for radon in Wisconsin?

Winter is peak testing season in Wisconsin. Homes are closed up with the heat running, which tends to draw and hold the most radon, so a cold-weather test reflects the conditions your household breathes for months. You can test any time of year, but a winter short-term test gives a realistic worst-case picture for a heating-climate state.

Radon Testing in Wisconsin

You cannot see, smell, or taste radon, which is exactly why a test is the only way to learn what your home in Wisconsin is holding. Radon is a naturally occurring radioactive gas that rises from the soil and collects indoors, and its level in any given house is impossible to guess from the outside. Winter is peak testing season here, because a closed-up home with the heat running tends to draw and trap the most radon, so the number you get in January reflects the air your household actually breathes for months. Badger State Radon is a free matching service, not a contractor or a lab, so the sections below explain how testing works and, if your result comes back high, connect you with an independent local radon professional.

Why test in Wisconsin

Wisconsin sits on soils and bedrock that push radon indoors at rates worth taking seriously. About one in 10 homes in the state is above the EPA action level of 4.0 pCi/L, and in higher-risk counties such as Dane the share climbs closer to one in five, according to the Wisconsin Department of Health Services. Radon is the leading cause of lung cancer among people who do not smoke and is linked to about 21,000 lung cancer deaths a year in the United States, according to the EPA. That is the reason to test rather than assume: the only way to know your home's level is to measure it, and the winter heating season is when most Wisconsin homes read their highest. For the statewide picture and how counties compare, see the Wisconsin radon guide.

Types of radon tests

Three kinds of test cover almost every situation, and the right one depends on how quickly you need an answer and how precise you want it to be.

Short-term (charcoal): an activated-charcoal kit sits in the lowest lived-in level for two to 90 days, then goes to a lab. It is the fast option, good for a first screening or a home sale where time is short.
Long-term (alpha-track): an alpha-track detector stays in place for 90 days or more and captures a better annual average, since radon rises and falls with the seasons and the weather. Choose this when you want to know how the house behaves across the year.
Continuous radon monitors: an electronic device logs hourly readings and shows how the level moves day to day. Professionals often use these for real-estate measurements and for pinpointing problems.

A short-term charcoal kit is the most common starting point for a homeowner. If that number is high, or if you want the truest yearly figure before spending on a system, a long-term test fills in the picture.

The real-estate test protocol

When radon is tested during a home sale, it follows a stricter recipe than a casual screening. The recognized approach is a minimum 48-hour test under closed-building conditions: closed-building conditions are started at least 12 hours before the test begins and held throughout, meaning windows and outside doors stay shut except for normal entry and exit. That keeps the reading honest, since an open window can wash radon out and hide a real problem. The EPA describes this measurement protocol in its radon standards of practice, and it is the protocol most inspectors and contractors use during a transaction. If you are buying or selling and a test comes back high, our radon mitigation at a home sale page walks through the tighter timeline a sale creates.

Reading your result and the follow-up

Results come back in picocuries per liter of air, written pCi/L. At or above the EPA action level of 4.0 pCi/L, the EPA recommends confirming the reading with a follow-up test before you pay for a system, because a single short-term test is a snapshot and levels move. Between 2 to 4 pCi/L you may still decide to reduce the level, since there is no known safe amount of radon. If your number lands at or above the action level, the fix is a mitigation system, and radon mitigation explains how the common sub-slab approach works. To make sense of a specific reading, our guide on radon test results explained breaks down what each range means and what to do next.

Where to get a test in Wisconsin

Wisconsin makes testing easy and inexpensive. The state runs 17 regional Radon Information Centers that together serve all 72 counties, and they sell low-cost kits, typically about $15 including the lab analysis. You can locate your center through the Wisconsin DHS radon information center directory or by calling the national radon hotline at 1-888-LOW-RADON (1-888-569-7236). Hardware stores and online retailers stock kits too, usually about $15 to $40. Whichever route you take, follow the kit instructions on placement and closed-building conditions so the result reflects your home and not the weather that week.

Who you get matched with

Testing is something many Wisconsin homeowners can do themselves with a mail-in kit. If the result comes back at or above the action level, that is where a professional comes in, and Badger State Radon connects you with an independent local radon professional who measures and mitigates in your area. Wisconsin does not license radon contractors, so the market is open; the professionals you are matched with work locally and can hold the voluntary national credentials from the National Radon Proficiency Program (NRPP) or the National Radon Safety Board (NRSB). Badger State Radon does not test, does not mitigate, and does not hold any radon certification. We match you quickly and step back so you can compare the plan and the quote yourself.