Lesson 7

How do you conduct a radon test?

Slide 7-2

Procedure for a radon test

1. Preparing for a test2. Preparing the residents3. Conducting the test

Slide 7-3

Prepare for the test• Determine timing of the test

– How long test will last– Appropriate weather conditions during

test period– Convenience of owner or resident

• Determine the placement of the device

• Consider how to prevent or detect interference

Slide 7-4

Prepare for the testTopics to be covered in lesson on

quality control• Prepare necessary documents• Prepare the device you will use

Slide 7-5

Determine timing of test

• How long test must run– At least 48 hours for most devices– Some devices require longer test period

• Convenience of owner or resident– Consideration helps encourage

cooperation• Weather predictions for the test

period

Slide 7-6

Weather conditionsCheck local news stations for weather forecasts

• Heavy rain storm• Hurricane• Major snow storm• Rapid barometric

pressure changes• High winds

(greater than 30 mph)

Do not test• During extreme weather• When extreme weather

is predicted within 48 hours

Slide 7-7

Extreme weather effects

Rain, snow, or freezing temperatures• May seal soil and prevent radon from moving to outdoor air• May thus increase indoor radon level

High winds (greater than 30 mph)• Create greater difference in indoor and outdoor air pressure• Make radon concentrations more variable• OK to test if high winds are normal for area (for example,

along coast)

Slide 7-8

Extreme weather effects

• May change rate of radon entry

• Create greater difference in indoor and outdoor air pressure

Record barometric pressure to identify

weather conditions that may affect the test

Rapid changes in barometric pressure

Slide 7-9

Determine placement of the device

1. Which level of the home?

2. Which room on that level?

3. What location within the room?

See handout 7-1

Slide 7-10

Choose the level to test

• If the home is not being sold, test at lowest level where people actually live

• Example– Owners use unfinished

basement only for storage

– Test on the main floor

• If the home is being sold, test at lowest level where people could live without renovating the area

• Buyers should discuss and agree on placement

• Example– Buyers intend to use

finished basement as bedroom for teenage son

– Test in basement

EPA: Test at the lowest level suitable for occupancy

Slide 7-11

Consider foundation types

If a home has more than one type of foundation, test in or above each area

For example• If home has a basement

that is or could be a living space, test in the basement

• If home has a crawl space, test in the room above the crawl space

• If home has a room with a cement floor ("slab-on-grade"), test in that room

Slide 7-12

A practical question

Worst-case

scenario

Many inspectors always test the lowest level where people could live to identify all potential issues for a home buyer

To test, or not to test,

in an unfinished basement?

Slide 7-13

Choose the room to test

Examples• Bedroom• Living room• Family room• Den• Playroom

Why?

Select a room that is used or will be used regularly

These are rooms where people usually spend a lot time

Slide 7-14

Rooms to avoid• Kitchen

– Usually has exhaust fan– Airborne particles may

affect measurement• Bathroom

– People spend relatively little time there

– High humidity may affect some devices

• Laundry room– Dryer exhausts air– High humidity

• Hallway– People usually spend

little time there• Closet

– People usually spend little time there

• Crawl space– People usually spend

little time thereWhy?

Slide 7-15

Which rooms may be suitable for testing?

Assume this plan represents the appropriate level in this home

Hallway

Kitchen Master bedroom

Living room

Bathroom Bathroom

Family roomGarage

Laundry room

Clos

et

Slide 7-16

Which rooms may be suitable for testing?

Family room

Master bedroom

Living room

Remember to check with the buyer about future use

Slide 7-17

Choose the location within the room

Place the device• Where it will not be disturbed• Where there is enough room

• In the breathing zone– More than 20 inches

from the floor– For devices that hang

from the ceiling, 6 to 8 feet from the floor

• More than 1 foot from exterior walls that have no windows or other potential openings

• More than 3 feet from windows, doors, or other potential openings in the exterior wall

• More than 4 inches from other objects

Slide 7-18

Locations to avoidLocations Examples

Where device might be disturbed during test

Where children or pets might bump device

With drafts From doors, windows, fans, or ceiling fansFrom heating, ventilating, and air conditioning vents

With high heat Near fireplacesIn direct sunlightNear appliances

With high humidity Bathrooms Kitchens

Slide 7-19

More locations to avoid

Cracks in a wall Sump pump

Slide 7-20

Choose a location within a room

Bed

WindowNight-stand

DoorDesk

4’

2’

14’

Exterior wallExterior wall

Interior wall2’In

terio

r wal

l

Bookcase

10’ What other information would you

need?

Explain your choice

Slide 7-21

Test interference

Accidental interference Intentional interference

Rado

n de

vice

Oops!Oops

!

Any change in test conditions before or during measurement that changes • Concentrations of radon or RDPs• Performance of measurement device

Rado

n de

vice

Slide 7-22

Common forms of interference

• Change the concentration of radon or RDPs– Open windows or

doors– Increase ventilation

• Influence the device– Move device– Block sampling

mechanism– Cover device– Turn off device– Apply heat or

humidity

Slide 7-23

Approaches to interference

• Detect interference • Prevent interference

CAN PREVENT FOREST FIRES

Test interference

Slide 7-24

Methods to detect interference

• Use a continuous device that frequently records radon levels to detect unusual changes

• Use a motion detector that shows whether the device has been moved

• Use a proximity detector that shows whether people have been in the room when radon levels have changed

• Use a device that does not allow residents to see preliminary results

Slide 7-25

More methods to detect interference

• Record the temperature and humidity frequently to indicate whether doors or windows are opened during the test

• Carefully place the device– Place precisely so you can detect any change of position– Place at edge of support to discourage covering device

• Apply seals (caulk or tape)– To device to indicate whether it is opened– To nearby windows and doors to show if they are

opened – Between device and its support to show if device is

moved– To device and other components to indicate tampering

Slide 7-26

Seals• Must stick to many surfaces• Must be easy to remove

without damaging the surface

• Must not be resealable or must show evidence of interference

• Must be unusual enough to prevent seller from duplicating

• Should be visible to discourage tampering

Just kidding.Not this kind

of seal.

Tamper-evident seal

Slide 7-27

Questions?About preparing for the test

Slide 7-28

Prevent interferencePrepare residents for test

Before test starts• Explain purpose of test• Explain test procedure and conditions • Explain importance of cooperating with

test requirements• Give residents written information about

test• Ask them to sign agreement to

cooperate with test requirements• Answer their questions

How?How?How?

Slide 7-29

Explain purposeThe people who are interested in buying your home want to know the level of radon. Radon is an invisible radioactive gas that causes lung cancer. The only way to know if you have a dangerous level of radon is to measure it. This test will measure the radon in the air in your home.If your home does have a high radon level, a system to reduce the level should be installed to protect the health of everyone who lives there.

Inspector Hank James

Slide 7-30

Explain test procedure

I’ll place two charcoal canisters in your basement around 8 AM on Wednesday, if that’s convenient for you.

These devices are harmless. Although they measure a radioactive gas, they are not radioactive.

They’ll need to remain in place for at least 48 hours. I’d like to pick them up around 10 AM Friday. Does that schedule work for you?

Slide 7-31

Explain conditionsfor short-term test

You’ll need to maintain some simple conditions to make sure that the test is accurate.

Starting 12 hours before the test and during the whole test, please keep your home closed as much as possible. Since the test will last 48 hours, your home must stay closed for 60 hours in all.

Keep all windows, outside vents, and outside doors closed. Of course, you may open a door to enter or leave your home, but close the door quickly.

Please shut down internal-external air exchange systems, such as your attic and window fans. You do not need to turn off your furnace fan.

You mentioned that your home already has a radon mitigation system installed and that it is working properly. Please make sure that the fan is running at least 24 hours before we start the test. And keep the system running during the entire test.

Slide 7-32

Explain importance of cooperation

It is standard procedure for me to use methods that detect and document interference. If I have evidence of interference, the test will not be valid and the results will not be accepted.

Interference means • Changing the test conditions (for example, by opening windows) or • Disturbing the device (for example, by moving it). And I should tell you that interfering with the test may actually increase, rather than decrease, the radon level we are measuring.

I’ll ask you to sign a document stating that you will maintain the required test conditions and will not disturb the device.

Thanks for your cooperation.

Slide 7-33

Sample agreement• See handout 7-2

Slide 7-34

Ask residents if they have questions

Common questions• Why test?• Where?• When?• How long?• Is it safe?• What do you mean by

closed conditions?• What do you mean by

interference?

Role play your answers to Rick, the reluctant resident

Slide 7-35

Questions?About preparing residents for the test

Slide 7-36

Conducting the test• Show a photo identification to

the client and resident• Place device or devices in

appropriate location• Remind residents

– How long test will take (at least 48 hours)

– Not to disturb device– To operate heating or recirculating air

conditioning system normally – If radon-reduction system is already operating,

to continue operating it during test

Slide 7-37

Conducting the test

• Confirm that home has been closed for at least 12 hours before the start of the test

• Remind residents– To keep home closed as much as possible– To operate only air-conditioning units that

recirculate interior air

For short-term tests (less than 1 week)

Slide 7-38

Document the test• Information about

device– Manufacturer – Type/model– Serial or ID number

• Times– Start date and time – Stop date and time

• Exact location of device on diagram of room and building

• Other building information– Type of building– Type of heating

system– Foundation types– Operation of

humidifiers, air filters, electrostatic precipitators, and clothes dryers

• Test conditionsSee handout 7-3

Slide 7-39

At end of test• Collect device• Confirm that test

conditions (closed house) were maintained

• Confirm that device was not interfered with

• Complete documents• Send device to lab

promptly

Slide 7-40

Report results• Report radon results in pCi/L

– Report no more than 1 decimal place– Example: 4.3 pCi/L

• Report radon decay products results in WL– Report no more than 3 decimal places– Example: 0.033 WL

If you convert between pCi/L and WL, explain conversion

Slide 7-41

Summary Preparing for a test

• Determine timing for test

• Determine placement of device– Level in home– Room– Location within

room

• Consider how to prevent or detect interference with test– Interference with

test conditions– Interference with

device

See handout 7-4

Slide 7-42

SummaryPreparing residents

• Explain purpose of test• Explain test procedure and

conditions • Explain importance of

cooperating with test requirements

• Give residents written information about test

• Ask them to sign agreement to cooperate with test requirements

• Answer their questions

Slide 7-43

SummaryConducting the test

• Place device in appropriate location• Remind residents of test conditions• Document the test• Check for interference• Send device to lab promptly• Report results

Slide 7-44

Questions?

Slide 7-45

Check your understanding

• See handout 7-5

Slide 7-46

Video review• See EPA’s Breathing Easy: What

Home Buyers and Sellers Should Know about Radon