The scope of this course addresses residential radon testing which carry two primary protocols to determine the presence of elevated radon levels indoors and the subsequent need for mitigation:
A) Extended Testing
A residential test conducted for a concerned homeowner not involved in a real estate transaction should begin with a short-term test under closed-building conditions and followed up with an additional short-term test in an opposite season or a long term test in order to determine the need for mitigaiton. The protocol for follow-up testing is as follows:
Initial Short-Term Test Result | Follow-Up [Extended] Test Protocol | Notes |
Between 4.0 pCi/L and 8.0 pCi/L | Short-term or long-term test | Conduct follow-up testing in an opposite season when possible. |
Over 8.0 pCi/L [more than double the action level] | Short-term test | |
Below 4.0 pCi/L | Retest every 5 years See Section 4.3.1 | When initial results are between 2.0 pCi/L and 3.9 pCi/L, consider a follow-up test during an opposite season. |
The results of any two tests may be averaged and used to determine the need for mitigation. | The results of any two tests may be averaged and used to determine the need for mitigation. |
B) Time-Sensitive Testing
Due to the time-sensitivity of a real estate transaction, radon tests should begin with a short-term test under closed-building conditions to a achieve results quickly. Since radon levels tend to vary from day to day and season-to-season, a short-term test is less likely than a long-term test to reveal the year-round average radon level. However, the assumption is that since the short-term test is conducted under closed-building conditions a low reading is likely to mean the annual average will also be low and a decision can be reasonably made whether or not mitigation efforts should be taken.
A radon measurement conducted during a time-sensitive real estate transaction carries a unique set of protocol due to the multiple parties and financial interests involved. Typically, the measurement professional is hired by the buyer in a real estate transaction to test a property that is controlled by another party with financial interest. Using due diligence in the real estate transaction test is imperative in order to obtain the most accurate results possible in the least amount of time allowed. Lack of diligence could result in devastating affects to the buyer and/or seller. A buyer who receives a false-low reading will live in a home that is otherwise thought to be free of a radon problem. The buyer who receives a false-high reading may ask the seller to fix the home unnecessarily. Two unique protocols exist for conducting radon tests involved in a real estate transaction [time-sensitive].
Option 1: Simultaneous Testing with Passive Devices
Option 2: Continuous Monitor Testing
Options for Testing in Real Estate Transactions
Option | Method | Special Device Protocols | Analysis & Interpretation |
1 | Simultaneous Testing w/ 2 Passive Devices [Time Integrating Devices] | Co-located and spaced 4 to 5 inches apartExposed for the same measurement periodProduce results in same units (pCi/L or WL) | Report individual results and overall average as a determination for mitigation. |
2 | Continuous Testing w/ Active Devices [Continuous Monitors] | One continuous monitor may be deployed in lieu of 2 passive devices. Must be able to integrate, record, and produce hourly readings. | Single result is sufficient as a determination for mitigation. |
Note: It is universally recommended that all initial testing begin with a short-term test [time-sensitive protocols] conducted under closed-building conditions to alert residents quickly if elevated concentrations of radon are present in the home. Follow-up testing conducted under extended test protocols, is recommended to confirm the initial test results.
Device Location
At the very least, a radon measurement should be conducted in the lowest structural area suitable for occupancy over each foundation. For example, a split level building with a basement, a slab-on-grade room and a room over a crawlspace must have measurements made in each foundation types: the basement, a slab-on-grade room and a room over the crawlspace. Regardless of whether multiple testing locations are required, devices should be put in a room that is used regularly (like a living room, playroom, den, or bedroom). Charcoal devices must not be placed in kitchens, laundry rooms, spa rooms or other areas of high humidity.
In general, the following placement protocols are universally accepted. However, individual state regulations supersede any recommendation made in the following section.
Measurement devices must be:
Note: Charcoal devices should not be placed in bathrooms, kitchens, laundry rooms, spa rooms or other areas of high humidity, closets, cupboards, sumps, crawlspaces or nooks within the foundation.
Closed-Building Conditions [CBC]
The following CBCs should be initiated at least 12 hours prior to any test lasting less than 96 hours and for the duration of any test lasting less than 7 days.
Protecting the Chain of Custody
All devices, whether for radon gas or working level measurements, should be tracked and custody information logged including: