Skip to content
RADON411

First Alert

First Alert RD1

Short-term charcoal radon test kit

  • Short-term kit
  • 2 to 4 days
  • Charcoal
  • Lab fee included

Best for, and skip if

Best for you if

  • You want a first test of a home without buying an electronic device.
  • You can keep windows and outside doors closed for the whole test and the 12 hours before it.

Skip it if

  • You want to watch radon change over weeks or months; a two-to-four-day test is a snapshot.
  • You need a long-term result; the EPA counts tests over 90 days as long-term, and First Alert's leaflet points to Alpha Energy Labs for one.
See how it compares: Best radon test kits, every kit comparedWho it fits
  • First Alert RD1

Photos: First Alert

Available at Amazon (opens in a new tab)Check price on Amazon (opens in a new tab)

As an Amazon Associate, Radon411 earns from qualifying purchases.

Amazon and the Amazon logo are trademarks of Amazon.com, Inc. or its affiliates.

See ratings and reviews on Amazon (opens in a new tab)
  • Test length2 to 4 days
  • MethodCharcoal
  • Lab feeIncluded
  • Every figure checked against the specifications First Alert publishes
  • Independent test results shown the same way for every product, unranked
Compare with similar items

About this item

As First Alert states it

  • How it measures: Activated charcoal (activated carbon), laboratory analysis
  • Exposure time: 2 days to 4 days
  • Lab fee: Included in the kit
  • Power: None needed
  • Units: pCi/L, in the laboratory report

The First Alert RD1 is a short-term, do-it-yourself charcoal radon test: you leave the sampler on the lowest level of your home for two to four days, then mail it to the laboratory, and the lab fee is included except for New Jersey's state fee. First Alert says results are available 3 to 5 business days after the lab receives the kit.

What you get

First Alert says the kit includes everything needed to test, with the lab fee, plus information on how to read the result and what to do if radon is high. The leaflet refers to a Radon Test Information Card in the kit for full instructions. The model is RD1, UPC 029054850003, weighing 0.4 lb, with a 1-year limited warranty; its store also lists a six-pack, RD-6.

In the box and running costs

How it works

What it measures and how

The sensor, the sampling and the readings, then who has checked it

How it works

In our words, from the maker's documents

The RD1 is a passive charcoal test. First Alert's leaflet describes the sampler as containing charcoal (activated carbon) that adsorbs and traps radon's radioactive by-products while it sits open in your home. Nothing in it runs on power and nothing displays a number: the measurement happens later, when the laboratory analyzes what the charcoal collected.

That design is one of the passive kinds of device the EPA describes for short-term testing. The EPA names charcoal canisters and charcoal liquid scintillation devices among the detectors most commonly used for short-term tests, and says short-term tests stay in a home for two days to 90 days, depending on the device. The RD1's exposure of two to four days sits at the short end of that range.

The analysis is part of the price. First Alert's leaflet says the radon analysis is completed by an EPA NRPP certified radon testing lab through NEHA, and names Alpha Energy Labs; New Jersey residents must send an additional state fee with each kit. First Alert describes the kit as listed under the EPA Radon Gas Measurement Proficiency Program; that is the maker's description, quoted as its own.

Because a short-term test captures only a few days, its result is a snapshot. The EPA notes that radon levels tend to vary from day to day and season to season, and that a long-term test is more likely than a short-term test to tell you a home's year-round average. The RD1 leaflet repeats the EPA's follow-up steps for each result band, and says a long-term test can be bought directly from Alpha Energy Labs.

What the manufacturer says

First Alert's own statements, attributed

  • First Alert saysFirst Alert states the kit includes test materials and lab fees, excluding New Jersey state fees.
  • First Alert saysFirst Alert states results are available 3 to 5 business days after the lab receives the kit.
  • First Alert saysFirst Alert describes the RD1 as listed under the EPA Radon Gas Measurement Proficiency Program.
  • First Alert saysFirst Alert states the kit is recommended for use only within the United States, with a 1-year limited warranty.

These are First Alert's own statements, attributed to it. They are not our findings, and we have not tested this product ourselves.

Independent evidence

Who checks a device like this

C-NRPP's consumer evaluation covers electronic monitors, not laboratory-analyzed test kits, so it has no result for First Alert RD1. A kit's result comes from the laboratory that analyzes it. Where the maker names that laboratory, or the page cites the National Radon Safety Board's lists of approved devices and accredited laboratories for it, the “How it works” panel and “Questions people ask” say so.

First Alert RD1

Check price on Amazon (opens in a new tab)

Specifications

Specifications

Every figure as the maker states it

Compare side by side

The maker's figures

Type
Short-term test kit, activated charcoal, mail-in
How it measures
Activated charcoal (activated carbon), laboratory analysis
Exposure time
2 days to 4 days
Lab fee
Included in the kit
Power
None needed
Units
pCi/L, in the laboratory report

What is in the box

First Alert says the kit includes everything needed to test, with the lab fee, plus information on how to read the result and what to do if radon is high. The leaflet refers to a Radon Test Information Card in the kit for full instructions. The model is RD1, UPC 029054850003, weighing 0.4 lb, with a 1-year limited warranty; its store also lists a six-pack, RD-6.

What it costs to run

A charcoal kit is used once. The lab analysis is included, except New Jersey's state fee, which the leaflet says residents send with each kit. Check whether return postage is prepaid when you buy. The other likely cost is a second test: the EPA says to take a follow-up test when a first short-term result is at or above 4 pCi/L.

Fit and setup

Who it fits, and how to use it

The fit, then setup and placement as the guidance asks

Who it fits

Good fit if, and look elsewhere if

Good fit if

  • You want a first test of a home without buying an electronic device.
  • You can keep windows and outside doors closed for the whole test and the 12 hours before it.
  • You want a laboratory result, with the lab fee included in the kit.
  • You are testing in the United States outside New Jersey, or are ready to pay New Jersey's separate fee.

Look elsewhere if

  • You want to watch radon change over weeks or months; a two-to-four-day test is a snapshot.
  • You need a long-term result; the EPA counts tests over 90 days as long-term, and First Alert's leaflet points to Alpha Energy Labs for one.
  • You cannot mail the sampler promptly after the test ends.
  • You need a test for a home sale; check what your state requires, which may be a certified tester.

Setup and placement

3 steps

  1. First Alert's instructions are short: leave the sampler out in the lowest level of the home or office for two to four days, then mail it to the lab immediately. The leaflet asks you to write down the bar code number on the back of the kit, the test location and the date you sent it.
  2. Closed-house conditions matter more for a short test than a long one. The EPA says to close windows and outside doors at least 12 hours before a test lasting two or three days and to keep them closed as much as possible during it; heating and air-conditioning fans that re-circulate air may run, but not fans that bring in air from outside. First Alert's leaflet adds to test when the weather is calm, since high winds or thunderstorms can alter radon levels, and names the winter months as the optimum time to test in northern climates.
  3. For where to put it, the EPA's guidance applies: the lowest lived-in level, in a room used regularly but not the kitchen or bathroom, at least 20 inches above the floor, and away from drafts, high heat, high humidity and exterior walls.

For where any radon test or monitor should sit in a home, see where to place a radon test.

Compare

Compare with similar items

The same three rows for each, and the one difference that matters

Compare side by side

More short-term test kits7

All short-term test kits

Questions

Questions people ask

5 questions about the First Alert RD1, answered

Asked about the RD1

How long does the First Alert RD1 test take?

First Alert says to leave the sampler out for two to four days and then mail it to the lab immediately, and that results are available 3 to 5 business days after the lab receives it. The EPA's minimum for any radon test is 48 hours.

Is the lab fee included?

Yes, except in New Jersey. First Alert says the kit includes test materials and lab fees, excluding New Jersey state fees, and the leaflet says New Jersey residents are required to send a fee with each kit.

What should I do with the result?

Follow the EPA's steps, which the RD1 leaflet reprints: if a first short-term test is at or above 4 pCi/L, test again, with a long-term test or a second short-term test; fix the home if a long-term follow-up is at or above 4 pCi/L, and consider fixing if the average of the two short-term tests is at or above 4 pCi/L. The EPA also suggests considering a fix between 2 and 4 pCi/L.

Does a charcoal kit work in summer?

It works whenever closed-house conditions can be kept. First Alert's leaflet calls the winter months the optimum time to test in northern climates, and that in southern climates the test should run when windows and doors will not be opened for ventilation; recirculating central air conditioning can keep running.

Can I use the RD1 for a home sale?

Rules for testing during a sale vary by state. The EPA describes tests for a sale and the conditions they need; check your state's requirements before relying on any do-it-yourself kit.

What to do next

Updated October 1, 2026