Special Testing Conditions

Certain testing situations can require special considerations. This guide is not intended to cover all circumstances nor is it a replacement for reading, understanding, and following proper testing protocol. A certified radon professional is necessary in some situations. It is the responsibility of the person performing the test to know and follow all applicable testing protocols.

In general, the ANSI-AARST standards should be followed and are available here.

Single Family Homes – Non-Real Estate Testing

Single family homes should be tested according to the ANSI-AARST MAH-2019 standard. Alpha Energy Lab’s testing instructions have been designed in accordance with this standard, however, the provided instructions cannot cover all possible circumstances.

In general, one test should be placed per 2,000 square feet. The test should be placed on the lowest level of the home which could be inhabitable (even if this area is currently unfinished). Additional tests should be placed for larger homes, homes with multiple independent heating/cooling systems, or homes with multiple foundation types. If a home has multiple foundation types, place at least one test over each foundation zone. If a home has multiple heating/cooling systems, place at least one test in each heating/cooling system area.

Single Family Homes – Real Estate Testing

Single family homes should be tested according to the ANSI-AARST MAH-2019 standard. Real Estate testing has additional requirements. In some states, it may be required to have a certified radon professional perform the testing. Contact your State Radon Official to determine your local laws.

Real Estate Testing can be performed under two different protocols – Time Sensitive Protocol and Extended Testing Protocol.

Time Sensitive Protocol (most common): Place two tests about 4 inches apart, side-by-side in the same location at the same time. This is called a “Duplicate” test. Place these tests on the lowest level of the home which could be inhabitable. Additional tests may be necessary for larger homes or those with multiple foundation types (see above). The average of the two tests results is used to determine if further action is needed for this home.

Extended Testing Protocol: Place a single test on the lowest level of the home which is currently inhabitable. Additional tests may be necessary for larger homes or those with multiple foundation types (see above). If the result of this test is more than 8 pCi/L, a second short term test should be conducted without delay.  If the result of the test is between 4 and 8 pCi/L, a follow up short term or long-term test should be conducted. If the result of the test is less than 4 pCi/L, no further action is necessary currently.

Daycare Testing

Daycare protocol depends on the size of the building. Daycares operated out of single-family homes should test according to ANSI-AARST MAH-2019. Daycares operated out of commercial buildings should be tested according to ANSI-AARST MALB-2014 (see the Schools and Large Buildings section below.)

Assisted & Senior Living Facilities

Assisted living and senior living facilities are generally tested according to ANSI-AARST MAMF-2017, as these buildings are typically occupied as dwellings. See the Multifamily Buildings section below.

Schools and Large Buildings

Schools and Large Buildings should be tested according to the ANSI-AARST MALB-2014 standard. Testing for radon in schools and large buildings is complex and requires specialized training. We strongly recommend only certified radon professionals perform testing in schools and large buildings. Many factors are involved in planning testing, such as construction style, occupancy level, HVAC system design, seasonal heating/cooling, ect. 

In general, every room that is in contact with the ground should be tested, whether occupied or not. For upper floors which are not in contact with the ground, you should test at least one room on each floor, and test 10% of the rooms on the 2nd and 3rd floor above ground contact areas.

Rooms over 2,000 square feet, such as a gymnasium, should have at least one test placed per 2,000 square feet.

Additional Quality Control testing is necessary (see section below)

Multifamily Buildings (Apartments)

Multifamily Buildings should be tested according to the ANSI-AARST MAMF-2017 standard. Testing for radon in multifamily buildings is complex and requires specialized training. We strongly recommend only certified radon professionals perform testing in multifamily buildings. Many factors are involved in planning testing, such as construction style, occupancy level, HVAC system design, seasonal heating/cooling, ect. 

In general, every room that is in contact with the ground should be tested, whether occupied or not. For upper floors which are not in contact with the ground, you should test at least one room on each floor, and test 10% of the rooms on each of the higher floors.

Rooms over 2,000 square feet, such as a gymnasium, should have at least one test placed per 2,000 square feet.

In time-sensitive situations, Time-Sensitive Protocol may be used (the above is Extended Testing Protocol). To use Time-Sensitive Protocol, place two tests side-by-side in each location as duplicate tests and use the average result of the duplicate tests to determine whether further action is required.

Additional Quality Control testing is necessary (see section below)

Additional Quality Control

Quality Control is an essential part of any testing project. Professional radon testers should maintain a Quality Control plan and follow it strictly. Quality Control considerations are necessary both for each individual project as well as for all testing performed by a professional throughout a year. This guide will briefly cover basic quality control for a specific project. 

Three types of quality control measurements exist:

  • Blanks. A blank detector is not exposed to radon and is returned to the lab for analysis. This process ensures the detector can achieve a low reading and is not contaminated prior to use.
  • Duplicates. A duplicate is a second detector placed side-by-side (about 4 inches) from another detector. The purpose of this is to compare the two results against each other. Some deviation is expected, but the results should be similar.
  • Spikes. Spikes are detectors exposed to a known quantity of radon in a radon chamber. The purpose of this is to determine the accuracy of the detector. 

For Schools, Large Buildings, and Multifamily buildings, the Quality Control measurements should be performed at the following rates:

  • Blanks – 5% of testing locations for projects smaller than 50 test locations. For projects more than 50 test locations, 5% of testing locations or 9 blanks, whichever is greater. For projects more than 50 test locations, at least 3 Lab Transit, Office, and Field blanks are required.
    • Lab Transit blanks are returned to the lab immediately upon receiving the detectors. Lab Transit blanks ensure product received from the lab is in good condition and is not contaminated.
    • Office Blanks are stored in the office where detectors are normally stored. They are then returned to the laboratory with the sampling detectors. Office blanks ensure your storage and handling procedures do not introduce contamination to the detectors.
    • Field blanks are deployed in the field alongside the sampling detectors and returned to the laboratory with the sampling detectors. Field blanks ensure the deployment and shipping procedures do not introduce contamination to the detectors.
  • Duplicates – 10% of testing locations. For example, if 100 tests are placed, you should place an additional 10 duplicates.
  • Spikes – 3 spikes required if 100 or more locations will be tested. If less than 100 locations will be tested, spikes do not need to be performed for this project (but are still necessary no less than annually as a part of your overall QC plan). 

Below are a couple simple examples:

  • A school with 115 tests to be placed:
    • 9 blanks
      • 3 Lab transit
      • 3 Office
      • 3 Field
    • 12 duplicates
    • 3 spikes
    • 136 total tests required (115 + 6 + 12 + 3)
  • An apartment with 38 tests to be placed:
    • 2 blanks
      • All Field blanks
    • 4 duplicates
    • 0 spikes
    • 44 total tests required (38 + 2 + 4)
  • A large apartment with 475 tests to be placed:
    • 24 blanks
      • 5 Lab transit
      • 5 office
      • 14 field
    • 48 duplicates
    • 3 spikes