New Jersey Department of Environmental Protection


Summary of Testing Requirements

Updated 8/2/06

Following are guidelines for testing procedures that must be followed by schools.

New Jersey law (N.J.S.A. 26:2D-70 et seq.) states that buildings can be tested only by certified radon professionals or the owners of the buildings, except where individuals are exempted from this requirement by the DEP under N.J.A.C. 7:28-27.31. School districts may elect to have one or more employees from the district attend a DEP-approved training course on school testing in order to receive an exemption and identification number to conduct testing in that school district only. If an exemption is not received, schools must use certified radon businesses to conduct testing. Information regarding approved DEP training courses for school testing or a list of certified radon businesses can be obtained by calling the DEP Radon Information Line at (800) 648-0394 or (609) 984-5425, or accessing the DEP Radon Website at

Testers must use the U.S. Environmental Protection Agency (EPA) document, Radon Measurement in Schools (Revised Edition), EPA 402-R-92-014, July 1993, including the sheet entitled "Corrections in the Second Printing," as the basic guidance for testing schools. Radon testing businesses and schools conducting radon testing must use this specific document as guidance. The document may be obtained from the EPA Indoor Air Quality Info Line at (800) 438-4318.

Contracts for radon testing or remediation may be made either directly with a radon business certified by the DEP, or with a company that subcontracts to a DEP-certified radon business. In the latter case, the name of the certified radon business that will be used must be included in the contract.

Additional information on testing is provided in "School Radon Testing Program: Questions and Answers," provided at the DEP Radon Website,

The DEP recommends, as does EPA, that short-term tests be conducted on weekdays while the school is in session and the heating, ventilation, and air conditioning (HVAC) system is operating normally, during the cold weather months of October through March. Research has shown that these conditions provide the best assessment of students’ average exposure. Testing in warm weather, or on weekends or holidays, may not provide test results that reflect average exposure, due to the fact that windows may be open, the HVAC may be on different settings than on weekdays, repair work may be occurring, and so forth. All these conditions can greatly affect radon levels.

If schools feel they must test outside of the October through March period, or on weekends or holidays, they are required to document the reasons and maintain this documentation on file. Schools must also document what steps were taken to ensure that doors and windows are kept closed except for normal entry and exit, that the HVAC is operating as on weekdays, and that there are no unusual activities occurring in the building that could affect air currents and air pressure. Parents may request this if they become concerned about why testing was not done in the recommended way.

The DEP strongly recommends that testing not be done in the summer in buildings without central air conditioning, due to the very high likelihood that windows will be opened during the testing period.

It is recommended that the HVAC system be inspected prior to testing, and repaired or adjusted as appropriate so that there are no HVAC malfunctions that could affect test results.

All short-term tests should be done with the HVAC system operating at normal weekday settings, with the usual setback periods, and with the building closed except for normal entry and exit starting at least 12 hours before the beginning of a two- to five-day test.

To ensure valid test results, it is particularly important for short-term tests that doors and windows be kept closed except for normal exit and entry. Keeping doors and windows closed to the extent possible minimizes the unpredictable impact on radon levels caused by air currents and air pressure changes from outside weather conditions. These changes in air flow and pressure can have dramatic impacts on radon concentrations. If open doors and windows are observed during the test period and reported to the business analyzing test results, the business must state in their report to the school that the results could be invalid based on this observation. In this event, parents or staff may insist that testing be repeated to obtain valid test results.

To ensure cooperation of teachers and staff in maintaining closed building conditions, it is recommended that the principal of the school talk to teachers and staff personally about the importance of the test and keeping doors and windows closed. This has been found to be the most effective strategy in gaining cooperation. The DEP Radon website,, has a handout for teachers and staff that can be used in explaining closed building conditions.

If schools have compelling reasons to deviate from any of the recommendations in Radon Measurement in Schools, they should document the reasons and maintain this documentation on file at the school. Parents may request to see this if they become concerned about such deviations. School officials should not hesitate to contact the DEP Radon Section if they have questions about testing procedures, at (800) 648-0394.

The DEP recommends that the results of radon testing be posted in an area easily accessed by parents and the public. Test results should be accompanied by a fact sheet "Interpretation of Radon Testing Results" available at the DEP Radon Website, In addition, it is recommended that districts provide information to parents prior to testing and following testing, so that parents are fully informed of the testing program. This will minimize parent concerns about the purpose of testing and health consequences from radon. Samples of letters that can be used, and a basic fact sheet for parents, can be obtained at

When elevated levels (4 picocuries per liter or higher) of radon are found, it is recommended that affected areas be mitigated. New Jersey law (N.J.S.A. 26:2D-70 et seq.) requires that mitigation, including both design and installation, must be performed by certified radon mitigators. A list of mitigation businesses certified to conduct school mitigations can be found at It is recommended that mitigators follow the EPA document, Reducing Radon in Schools: A Team Approach, EPA 402-R-94-008, April 1994, which can also be obtained from EPA at (800) 438-4318. This document outlines a team approach in which mitigators work with school representatives or consultants familiar with the operation of the school’s HVAC system.

Additional information on the School Radon Testing Program can be obtained at, or from the DEP Radon Information Line at (800) 648-0394 or (609) 984-5425.


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Department of Environmental Protection
P. O. Box 402
Trenton, NJ 08625-0402