Free Radon Test Kits in Washington and Idaho

Washington: the Department of Health kit

Washington is the easier side of the state line. The Department of Health says “We have a limited supply of free radon test kits,” asks people to request one only if they are committed to testing, and gives 8 to 10 weeks for delivery. Ordering takes two steps: you enter an email address on an access form, and DOH replies with a link to the actual request form.

The request form comes in English, Spanish, Russian and Vietnamese. The home being tested must be in Washington, owners and renters can both apply, and a separate option covers daycare and early-learning facilities that are not home-based. Questions go to doh.radon@doh.wa.gov or 360-236-3246, the number printed on the form. All of this was current on the DOH pages on October 3, 2026.

Idaho: sold out, with a library fallback

Idaho’s Department of Health and Welfare normally mails one free short-term kit per household every two years. On October 3, 2026, its order page showed the kit as sold out and “not available at this time,” and the radon page, last updated September 16, 2026, carried the heading “Free Radon Testing in Idaho (Out of Stock).” When the kit is in stock, the shop asks for 2 to 3 weeks for delivery.

The fallback is the Radon Library Lending Program, which lets Idahoans check out a free kit at participating public libraries. The list on October 3, 2026 named 13 libraries and none in Kootenai, Bonner or Boundary County. The northernmost are in Plummer and Tensed, plus the Latah County Public Library in Moscow. DHW also links to discounted kits that can be ordered by credit card or by mail.

Low-cost kits by mail

Beyond state programs, EPA points to National Radon Program Services at Kansas State University, which sells kits online and by phone at 1-800-767-7236. Its short-term kit runs 2 to 4 days and its long-term kit 3 to 12 months, with lab analysis and return shipping included. Orders ship on Mondays and Thursdays and typically take one to two weeks after shipping.

Stores are the other route. Washington DOH notes that do-it-yourself kits are sold at hardware stores, home improvement stores and online, and the Spokane Regional Clean Air Agency told residents in January 2026 that DIY kits can be found at a local hardware store. Whatever the source, the kit includes its own lab and mailing instructions, and those instructions govern how long it stays out.

Placing the kit so the result counts

A free kit is only as good as where it sits. Washington DOH puts it bluntly: testing a broom closet or a crawl space where no one spends time “will tell you very little about exposure.” Put the device where the family actually spends hours, such as a basement TV room or a bedroom, and follow EPA’s general placement rules:

• •Use the lowest lived-in level: the basement if it is used often, otherwise the first floor.
• •Choose a room people use, not the kitchen or a bathroom.
• •Set the kit at least 20 inches above the floor, away from drafts, high heat, high humidity and exterior walls.
• •For a 2 or 3 day test, close windows and outside doors 12 hours before starting.
• •Check the use-by date, fill in every date and time on the form, and mail the kit as soon as the test ends.

If the result comes back high

One high reading calls for a follow-up test, in EPA’s words, “to be sure.” EPA treats a first result above twice the action level, so over 8 pCi/L, as a signal to take a second short-term test right away; under that, a long-term follow-up is also an option. EPA recommends fixing the home if one long-term test or the average of two short-term tests shows 4 pCi/L or higher.

High results are common here, which is no reason to assume one. Of 18,518 radon tests reported in Spokane County from 1990 through 2020, 8,704, or 47.0%, were at or above 4.0 pCi/L, according to the Washington Tracking Network. Those are self-selected tests, and none of them predicts a single house. For mitigation, Washington DOH links to the two national certification directories, NRPP and NRSB.

Common questions