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The following guidelines are condensed from the most recent U.S. EPA radon testing protocols.

Real Estate Testing requires that two (2) Pro Cheks be placed side-by-side (i.e., 6-12 inches apart) and the results averaged together.
The Air Chek Real Estate Reporting option will do the averaging for you automatically. Call 800-247-2435 if you would like to know more about our reporting options.

You may use this test during any season, as long as closed building conditions can be maintained. All external doors, windows, and vents should be kept closed from 12 hours before starting the test until the end of the test. You don’t need to change your normal entry and exit routines, just make sure you close the door behind you. If the building has a permanently installed radon mitigation system, air to air heat exchanger, and/or combustion air supplies for furnaces, etc., they should be operated normally. However, do not operate any whole house or window fans during the test. This test should not be started if severe weather is predicted. For example, a major storm system with winds exceeding 30 miles per hour.

This sampler is designed to be exposed 48 to 96 hours (two to four days). This means you must leave it in place for at least 2 days. You may expose it up to 4 days if you are not testing in a humid environment (over 55% relative humidity).

The US EPA says to test the lowest livable area of the building suitable for occupancy without major renovations. During real estate transactions there are often disagreements between the buyer and seller on where to test. Typically the buyer gets the final say depending on their anticipated use of the home. Communication is the key to making sure that each party understands the test location and testing protocols. The best booklet to reference is the EPA Home Buyer's and Seller's Guide to Radon.

Place the kits where they will not be disturbed. The preferred method is to hang the samplers centrally in the room. Kits should be placed within the normal breathing zone (2 to 6 feet from the floor). The sampler may be hung from an interior non-masonry wall. Thumbtacks, string and/or fishing line may be helpful for suspending the kits from a ceiling, book shelf, or light fixture. DO NOT place it in a draft. Keep it 3 feet or more from doorways, hallways, windows, exterior walls, and heating or air-conditioning vents. Do not place it in the same room with any type of operating fan or blower. Air blowing on or near an activated charcoal sampler may increase its sensitivity to radon. DO NOT place it near any heat source such as a stove, fireplace, or baseboard heater. Keep it out of direct sunlight. Heat may reduce the sensitivity of some radon measurement devices. DO NOT test areas of high humidity, such as bathrooms, kitchens, laundry rooms, closets, or damp basements. If you must test a damp or humid room (over 55% RH), then test only for the shortest recommended period. Moisture may reduce the sensitivity of some radon measurement devices. DO NOT place this sampler within 3 feet of another activated charcoal device. (Exception: you may place two of the same type and model of test device within 12 inches of each other when conducting a Real Estate or Quality Control check.)

A short note from our lab director Our laboratory has processed over two million radon tests and we have seen almost everything that can happen to a radon test sample. We have thousands of unreturnable test results stored in our computer, because of missing or unreadable information. You must provide complete readable information or a reprocessing fee may be charged before releasing results. Send the sample to the lab A.S.A.P. Radon does not last forever. When using the kits for Real Estate purposes, we STRONGLY recommend the use of courier services such as FedEx, UPS or DHL. Air Chek supplies discounted FedEx return services. You can go to for pricing from your zip code. If the sampler takes more than a week to get to our lab your test result will not be as accurate as one that arrived within three or four days. Over 8 days to our lab and you get only an estimated result. Over 12 days, NO result can be provided. If you have not received your test result within three weeks, send your name/address, the times, dates, serial number of the test, and any other pertinent information to:

Radon Lab
1936 Butler Bridge Rd.
Fletcher, NC 28732
Fax: 828-684-8498

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