1、Designation: E2121 11Standard Practice forInstalling Radon Mitigation Systems in Existing Low-RiseResidential Buildings1This standard is issued under the fixed designation E2121; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the
2、year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice describes methods for reducing radonentry into existing attached and detached residential buildi
3、ngsthree stories or less in height. This practice is intended for useby trained, certified or licensed, or both, or otherwise qualifiedindividuals.1.2 These methods are based on radon mitigation techniquesthat have been effective in reducing radon levels in a widerange of residential buildings and s
4、oil conditions. These fanpowered mitigation methods are listed in Appendix X1. Moredetailed information is contained in references cited throughoutthis practice.1.3 This practice is intended to provide radon mitigationcontractors with a uniform set of practices that will ensure ahigh degree of safet
5、y and the likelihood of success in retrofit-ting low rise residential buildings with radon mitigationsystems.1.4 The methods described in this practice apply to cur-rently occupied or formerly occupied residential buildings,including buildings converted or being converted to residentialuse, as well
6、as residential buildings changed or being changedby addition(s) or alteration(s), or both. The radon reductionactivities performed on new dwellings, while under construc-tion, before occupancy, and for up to one year after occupancy,are covered by Guide E1465.1.5 This practice also is intended as a
7、model set of practices,which can be adopted or modified by state and local jurisdic-tions, to fulfill objectives of their specific radon contractorcertification or licensure programs. Radon mitigation per-formed in accordance with this practice is considered ordinaryrepair.1.6 The methods addressed
8、in this practice include thefollowing categories of contractor activity: general practices,building investigation, systems design, systems installation,materials, monitors and labeling, post-mitigation testing, anddocumentation.1.7 The values stated in inch-pound units are to be regardedas standard.
9、 The values given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.1.8 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standar
10、d to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use. See Section 6 forspecific safety hazards.2. Referenced Documents2.1 ASTM Standards:2E631 Terminology of Building ConstructionsE1465 Practice for Radon Control Options for
11、the Designand Construction of New Low-Rise Residential BuildingsE1745 Specification for Plastic Water Vapor Retarders Usedin Contact with Soil or Granular Fill under Concrete Slabs2.2 Government Publications:EPA “Asbestos School Hazard Abatement ReauthorizationAct,” regulation 40 CFR Part 763, Subpa
12、rt E.3EPA “A Citizens Guide to Radon (Second Edition),” EPA402-K92-001, May 1992.3EPA “Consumers Guide to Radon Reduction,” EPA 402-K92-003, August 1992.3EPA “Handbook, Sub-Slab Depressurization for Low-Permeability Fill Material,” EPA/625/6-91/029, July1991.3EPA “Home Buyers and Sellers Guide,” EPA
13、 402K-00008, July 2000.3EPA “National Emission Standard for Asbestos,” 40 CFR61, Subpart M.3EPA “ Radon Mitigation Standards,” EPA 402-R-93-078,April 1994.3EPA “Radon Reduction Techniques for Existing DetachedHouses, Technical Guidance (Second Edition),” EPA/1This practice is under the jurisdiction
14、of ASTM Committee E06 on Perfor-mance of Buildings and is the direct responsibility of Subcommittee E06.41 on AirLeakage and Ventilation Performance.Current edition approved Nov. 1, 2011. Published December 2011. Originallyapproved in 2001. Last previous edition approved in 2009 as E2121 09. DOI:10.
15、1520/E2121-11.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from United States Environmental Pro
16、tection Agency (EPA), ArielRios Bldg., 1200 Pennsylvania Ave., NW, Washington, DC 20460, http:/www.epa.gov.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.625/587/019, revised January 1988.3EPA “Radon Reduction Techniques for Existin
17、g DetachedHouses, Technical Guidance (Third Edition) for ActiveSoil Depressurization Systems,” EPA/625/R-93-011, Oc-tober 1993.3NCRP “Measurement of Radon and Radon Daughters inAir,” NCRP Report No. 97, 1988.4NIOSH “Guide to Industrial Respiratory Protection,”NIOSH Publication No. 87116.5OSHA “Asbes
18、tos Standard for the Construction Indus-try” 29 CFR 1926.1102.6OSHA “Hazard Communication Standard for the Construc-tion Industry,” 29 CFR 1926.59.6OSHA “Occupational Safety and Health Regulations, Ioniz-ing Radiation,” 29 CFR 1910.96.6OSHA “Respiratory Protection Standard,” 29 CFR1920.134, 1998.6OS
19、HA “Safety and Health Regulations for Construction,Ionizing Radiation,” 29 CFR 1926.53.63. Terminology3.1 DefinitionsDefinitions of terms used in this practiceare defined in accordance with Terminology E631.3.2 Definitions of Terms Specific to This Standard:3.2.1 active soil depressurization (ASD),
20、na family ofradon mitigation systems involving mechanically-driven soildepressurization, including sub-slab depressurization (SSD),sump pit depressurization (SPD), drain tile depressurization(DTD), hollow block wall depressurization (BWD), and sub-membrane depressurization (SMD) (see Appendix X2).3.
21、2.2 backdrafting, na condition where the normal move-ment of combustion products up a flue (due to the buoyancy ofthe hot flue gases), is reversed, so that the combustion productsenter the building (see pressure-induced spillage).3.2.3 communication test, na diagnostic test to evaluatethe potential
22、effectiveness of a sub-slab depressurization sys-tem by applying a vacuum beneath the slab and measuring,either with a micromanometer or with a heatless smoke device,the extension of the vacuum field. Also called pressure-fieldextension test.3.2.4 contractor, nfor the purposes of this practice, acon
23、tractor is one who contracts to performs radon reductionactivities or is an employee of one who contracts to perform orperforms radon reduction activities, with the expectation thatpayment will be received for the work performed. A personwho does radon reduction activities as an employee of abuildin
24、g owner is also a contractor for purposes of this standardpractice. Persons whose normal activity is not radon reduction,but who do work related to radon reduction like indoor airquality consultants, radon consultants, plumbers, building con-tractors, or employees of these persons are all viewed asc
25、ontractors when performing radon reduction activities cov-ered by this practice.3.2.5 crawlspace depressurization (CSD) (active), na ra-don mitigation technique designed to achieve lower air pres-sure in the crawlspace than in the rooms bordering and abovethe crawlspace. A radon fan, draws air from
26、the crawl spaceand exhausts that air outside the building. Crawlspace depres-surization (CSD) is intended to mitigate rooms bordering andabove the crawlspace but not the crawlspace itself. All CSDsystems, for purposes of this practice, are active.3.2.6 depressurization, na negative pressure induced
27、inone area relative to another.3.2.7 diagnostic tests, nprocedures used to identify orcharacterize conditions under, beside and within buildings thatmay contribute to radon entry or elevated radon levels or thatmay provide information regarding the performance of amitigation system.3.2.8 drain tile
28、depressurization (DTD) (active), na typeof active soil depressurization radon mitigation system wherethe suction point piping attaches to a drain tile or is located ingas-permeable material near the drain tile. The drain tile orperimeter drain may be inside or outside the footings of thebuilding.3.2
29、.9 hollow wall depressurization (BWD) (active), naradon mitigation technique that depressurizes the void spacewithin a foundation wall (usually a block wall). A radon faninstalled in the radon system piping draws air from within thewall.3.2.10 manifold piping, nthis piping collects the flow ofsoil-g
30、as from two or more suction points and delivers thatcollected soil-gas to the vent stack piping. In the case of asingle suction point system, there is no manifold piping sincethe suction point piping connects directly to the vent stackpiping. The manifold piping starts where it connects to thesuctio
31、n point piping and ends where it connects to the ventstack piping.3.2.11 mechanically-ventilated crawlspace system, naradon-control technique designed to increase ventilation withina crawlspace by use of a fan.3.2.12 mitigation system, nany system or steps designedto reduce radon concentrations in t
32、he indoor air of a building.3.2.13 natural draft combustion appliance, nany fuelburning appliance that relies on natural convective flow toexhaust combustion products through flues to outside air.3.2.14 occupiable spaces, nfor purposes of this practice,are areas of buildings where human beings spend
33、 or couldspend time, on a regular or occasional basis.3.2.14.1 DiscussionExamples of occupiable spaces arethose that are or could be used for sleeping, a work shop, ahobby, reading, student home work, a home office, entertain-ment (TV, music, computer, etc.), physical work-out, laundry,games, or chi
34、lds play.3.2.15 pressure-field extension, nthe distance that a pres-sure change, created by drawing soil-gas through a suctionpoint extends outward in a sub-slab gas permeable layer, undera membrane, behind a solid wall, or in a hollow wall (seecommunication test).4Available from the National Commis
35、sion on Radiation Protection and Mea-surement, 7910 Woodmont Avenue, Suite 400, Bethesda, MD 20814, http:/www.ncrponline.org.5Available from Centers for Disease Control soil-gas is collected at oneend of the vent stack piping and is discharged from the buildingat the other end. In active soil depres
36、surization systems, theradon fan is installed in the vent stack piping.3.2.27 ventilation, nthe process of introducing outdoor airinto a building.3.2.28 working level (WL), na unit of radon decay productexposure. Numerically, any combination of short-lived radondecay products in one litre of air tha
37、t will result in the ultimateemission of 130 000 MeV of potential alpha energy. Thisnumber was chosen because it is approximately the total alphaenergy released from the short lived decay products in equi-librium with 100 pCi of Rn-222.3.2.29 working level month (WLM), na unit of exposureused to exp
38、ress the integrated human exposure to radon decayproducts. It is calculated by multiplying the average workinglevel to which a person has been exposed by the number ofhours exposed and dividing the product by 170.4. Summary of Practice4.1 This practice describes methods for mitigating elevatedlevels
39、 of radon in existing attached and detached residentialbuildings three stories or less in height.4.2 The mitigation process is described in terms of thecategories of activity associated with radon mitigation andincludes: general practices, building investigation, systemsdesign, systems installation,
40、 materials, monitors and labeling,post-mitigation testing, and contracts and documentation.4.3 The systems installation category contains subsectionsdescribing the specific requirements applicable to each of thecomponents of radon mitigation systems, for example, radonsystem piping, radon fans, seal
41、ing, electrical, etc.5. Significance and Use5.1 The purpose of the methods, systems, and designsdescribed in this practice is to reduce radiation exposures foroccupants of residential buildings caused by radon and itsprogeny. The goal of mitigation is to maintain reduced radonconcentrations in occup
42、iable areas of buildings at levels as lowas reasonably achievable. This practice includes sections onreducing radiation exposure caused by radon and its progenyfor workers who install and repair radon mitigation systems.The goal for workers is to reduce exposures to radon and itsprogeny to levels as
43、 low as reasonably achievable.5.2 The methods, systems, designs, and materials describedhere have been shown to have a high probability of success inmitigating radon in attached and detached residential buildings,three stories or less in height (see EPA, “Radon ReductionTechniques for Existing Detac
44、hed Houses, Technical Guidance(Third Edition) for Active Soil Depressurization Systems”).Application of these methods does not, however, guaranteereduction of radon levels below any specific level, sinceperformance will vary with site conditions, construction char-acteristics, weather, and building
45、operation.5.3 When applying this practice, contractors also shallconform to all applicable local, state, and federal regulations,and laws pertaining to residential building construction, re-modeling, and improvement.6. Safety Hazards6.1 Contractors shall comply with all OSHA, state and localstandard
46、s or regulations relating to worker safety and occupa-tional radon exposure. Applicable references in the Code ofFederal Regulations include those in 2.2. Contractors also shallfollow occupational radon guidance in 2.2.6.2 In addition to OSHA standards and NIOSH recommen-dations, the following requi
47、rements specifically applicable tothe safety and protection of radon mitigation workers shall bemet:E2121 1136.2.1 The contractor shall advise workers of the hazards ofexposure to radon and the importance of protective measureswhen working in areas of elevated radon concentrations. Inaddition, the c
48、ontractor shall advise employees of other poten-tial hazards according to the hazard communication standardfor the construction industry (see OSHA, “Hazard Communi-cation Standard for the Construction Industry”).6.2.2 The contractor shall ensure that appropriate safetyequipment, such as ventilators,
49、 respirators, hard hats, faceshields, and ear plugs, are available on the job site duringmitigation activities.6.2.3 Work areas shall be ventilated to reduce workerexposure to radon, dust, or other airborne pollutants.6.2.4 Consistent with OSHA permissible exposure limits,contractors shall ensure that employees are exposed to no morethan four working level months (WLM) over a 12-monthperiod (or the equivalent 68 000 pCi/L-h, when converted at anequilibrium ratio of 100 %. A WLM is calculated by multiply-ing the average working level to which a person has
