GB 50325-2020 English PDF

GB 50325-2020: Standard for indoor environmental pollution control of civil building engineering
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GB 50325-2020
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
UDC
P GB 50325-2020
Standard for indoor environmental pollution control of
civil building engineering
ISSUED ON: JANUARY 16, 2020
IMPLEMENTED ON: AUGUST 01, 2020
Issued by: Ministry of Housing and Urban-Rural Development of PRC;
State Administration for Market Regulation.
Table of Contents
Foreword ... 5 
1 General provisions ... 7 
2 Terms and symbols ... 8 
2.1 Terms ... 8 
2.2 Symbols ... 9 
3 Building materials ... 10 
3.1 Inorganic nonmetallic building materials ... 10 
3.2 Wood-based panels and finishing products ... 10 
3.3 Coatings ... 11 
3.4 Adhesives ... 12 
3.5 Water-based treatment agents ... 13 
3.6 Others ... 13 
4 Survey and designing for building engineering ... 16 
4.1 General requirements... 16 
4.2 Radon concentration measurement and resistance on construction sites ... 16 
4.3 Choice of construction materials ... 18 
5 Construction ... 20 
5.1 General requirements... 20 
5.2 On-site examination on building materials ... 22 
5.3 Requirements for construction ... 23 
6 Inspection and acceptances ... 25 
Appendix A Measurement of radon exhalation rate ... 30 
Appendix B Measurement of content of formaldehyde and VOC emission in
decorations materials using environmental test chamber ... 33 
Appendix C Measurements of radon concentration in soil and radon exhalation
rate ... 36 
Appendix D Measurement of indoor benzene, toluene, xylene ... 41 
Appendix E Measurement indoor TVOC ... 45 
Explanation of wording in this standard ... 49 
List of quoted standards ... 50 
Standard for indoor environmental pollution control of
civil building engineering
1 General provisions
1.0.1 This standard is formulated, in order to prevent and control indoor
environmental pollution, which is caused by main materials and decoration
materials, in civil construction projects; protect public health; safeguard public
interests; achieve advanced technology and economical rationality.
1.0.2 This standard is applicable to the control of indoor environmental pollution,
in newly constructed, expanded, reconstructed civil construction projects.
1.0.3 The indoor environmental pollutants, which are controlled by this standard,
include radon, formaldehyde, ammonia, benzene, toluene, xylene. total volatile
organic compounds.
1.0.4 The division of civil construction projects shall meet the following
requirements:
1 The category I civil buildings shall include residences, residential functional
apartments, hospital wards, elderly care housing facilities, kindergartens,
school classrooms, student dormitories, etc.;
2 The category II civil buildings shall include office buildings, shops, hotels,
cultural and entertainment venues, bookstores, libraries, exhibition halls,
gymnasiums, public transportation waiting rooms, restaurants, etc.
1.0.5 The main building materials and decoration materials, which are selected
for civil construction projects, shall comply with the relevant provisions of this
standard.
1.0.6 The indoor environmental pollution control of civil buildings shall not only
comply with the provisions of this standard, BUT also comply with the relevant
current national standards.
2 Terms and symbols
2.1 Terms
2.1.1 Civil building engineering
The general term for newly built, expanded, reconstructed civil building
structural engineering and decoration engineering.
2.1.2 Environmental test chamber
An equipment, which simulates the indoor environment, to test the release
of chemical pollutants from decoration materials.
2.1.3 Radon exhalation rate from the surface
The radioactive activity of radon, which is released from soil or material
surface per unit area and unit time.
2.1.4 Internal exposure index (IRa)
The quotient, which is obtained -- by dividing the specific activity of the
natural radionuclide radium-226 in the main building materials and
decoration materials BY the specific activity limit value of 200.
2.1.5 External exposure Index (Iγ)
The sum of the quotients, which are obtained by -- dividing the radioactive
specific activities of natural radionuclides radium-226, thorium-232,
potassium-40 in the main building materials and decoration materials BY the
specific activity limit values of 370, 260, 4200, respectively.
2.1.6 Radon concentration
The radioactive activity of radon per unit volume of air.
2.1.7 Wood-based panels
The panels or formed products, which are produced by using wood or non-
wood plant fibers as the main raw material; processing it into various material
units; applying (or not applying) adhesives and other additives; gluing
together. It mainly includes the products, such as plywood, fiberboard,
particleboard, surface decorative panels.
2.1.8 Wood-plastic composite products
3.5 Water-based treatment agents
3.5.1 For indoor water-based flame retardants (including fire-retardant
coatings), waterproofing agents, preservatives, enhancers and other water-
based treatment agents, in civil construction projects, it shall measure the
content of free formaldehyde; the limit shall not exceed 100 mg/kg.
3.5.2 The measurement method of free formaldehyde content in water-based
treatment agent shall be carried out, according to the method specified in the
current national standard "Determination of formaldehyde content of
waterborne coatings -Spectrophotometric method with acetylacetone" GB/T
23993.
3.6 Others
3.6.1 For concrete admixtures, which are used in civil construction
projects, the amount of ammonia released shall not be greater than 0.10%.
The measurement method of ammonia release shall comply with the
current national standard "Limit of ammonia emitted from the concrete
admixtures" GB 18588.
3.6.2 For the amount of ammonia, which is released from flame retardants, fire
retardant coatings, water-based architectural waterproof coatings, as used in
civil construction projects, it shall not be greater than 0.50%. The measurement
method shall conform to the current industry standard "Limit and test method of
harmful substances in fire-retardant coating" JG/T 415.
3.6.3 In the concrete admixtures, which can release formaldehyde AND is used
in civil construction projects, the amount of residual formaldehyde shall not be
greater than 500 mg/kg. The measurement method shall comply with the
current national standard "Limit of residual formaldehyde from the concrete
admixtures" GB 31040.
3.6.4 For the bonded wood structure materials, which are used indoors in civil
buildings, the free formaldehyde emission shall not be greater than 0.124
mg/m3. The measurement method shall comply with the relevant provisions in
Appendix B of this standard.
3.6.5 The free formaldehyde emission of indoor curtains and soft packs of civil
buildings shall not be greater than 0.124 mg/m3. The measurement method
shall comply with the relevant provisions of Appendix B of this standard.
3.6.6 The content limit of free formaldehyde, in indoor wallpaper (cloth) of civil
buildings, shall comply with the relevant provisions in Table 3.6.6. The
4 Survey and designing for building engineering
4.1 General requirements
4.1.1 For newly-built or expanded civil construction projects, before
design, it shall survey the radon concentration in the soil OR the radon
exhalation rate from the surface in the urban area, where the construction
project is located; submit the corresponding survey report. If the radon
concentration in the regional soil or the radon exhalation rate from the
surface has not been measured, it shall measure the radon concentration
in the construction site soil or the radon inhalation rate from the soil;
submit a corresponding test report.
4.1.2 The interior decoration and decoration design of civil buildings shall have
pollution control measures. It shall conduct pre-assessment of decoration and
decoration design pollution control; control the load ratio of decoration and
decoration materials AND the release of material pollutants; adopt advanced
technologies such as prefabricated decoration products; the finished products
and parts for decorative purposes should be processed in the factory AND
installed on site.
4.1.3 The indoor ventilation design of civil buildings shall comply with the
relevant provisions of the current national standard "Unified standard for design
of civil building" GB 50352. For civil building projects, which use the central air
conditioning, the fresh air volume shall comply with the current national
standard "Design code for heating ventilation and air conditioning of civil
buildings" GB 50736.
4.1.4 In areas with hot summer and cold winter, severe cold and cold areas, the
minimum ventilation frequency of category I civil buildings, which use the
natural ventilation, shall not be less than 0.5 times/h. If necessary, it shall take
mechanical ventilation measures.
4.2 Radon concentration measurement and resistance on
construction sites
4.2.1 For the engineering geological survey data of the newly-built and
expanded civil construction projects, it shall include the historical measurement
data of soil radon concentration or soil radon exhalation rate from the surface
AND the average data of soil radon concentration or radon exhalation rate from
soil the surface, in the urban area where the project is located.
4.2.2 For civil construction projects, for which regional measurement of radon
concentration in soil or radon exhalation rate from the surface has been carried
out, when the average value of soil radon concentration measurement results
is not more than 10000 Bq/m3 or the average value of measurement results of
the radon exhalation rate from the surface, is not more than 0.02 Bq/(m2·s),
meanwhile where there is no geological fracture structure at the site of the
project, the measurement of soil radon concentration may be exempted. In
other cases, it shall measure the soil radon concentration of the project site OR
the radon exhalation rate from the surface.
4.2.3 When the average radon concentration of the civil construction site is not
more than 20000 Bq/m3 OR the radon exhalation rate from the surface, is not
more than 0.05 Bq/(m2·s), the engineering measures for radon prevention may
be exempted.
4.2.4 When the measurement result of radon concentration in the soil of
civil construction projects is greater than 20000 Bq/m3 and less than
30000 Bq/m3, OR the radon exhalation rate from the surface is greater than
0.05 Bq/(m2 • s) and less than 0.10 Bq/(m2 • s), it shall take anti-cracking
measures at the ground floor of the building.
4.2.5 When the soil radon concentration of the civil construction site is
not less than 30000 Bq/m3 and less than 50000 Bq/m3, OR the radon
exhalation rate from the surface is not less than 0.10 Bq/(m2 • s) and less
than 0.30 Bq/(m2 • s), in addition to taking anti-cracking measures for the
ground floor of the building, the foundation must also be treated,
according to the grade-1 waterproofing requirements in the current
national standard "Technical code for waterproofing of underground
works" GB 50108.
4.2.6 When the average radon concentration in the civil construction site
is not less than 50000 Bq/m3 OR the average radon exhalation rate from
the surface is not less than 0.30 Bq/(m2·s), it shall take comprehensive
radon prevention measures for buildings.
4.2.7 When the average radon concentration in the soil of the category I civil
construction project site is not less than 50000 Bq/m3, OR the radon exhalation
rate from the surface is not less than 0.30 Bq/(m2•s), it shall measure the
specific activity of the radium-226, thorium-232, potassium-40 in the soil of the
project site. When the soil's internal exposure index (IRa) is greater than 1.0 OR
the external exposure index (Iγ) is greater than 1.3, the soil of the project site
shall not be used as engineering backfill.
4.2.8 For the method for measuring the radon concentration in the soil of the
civil construction site AND the method for measuring the radon exhalation rate
from the soil surface, they shall comply with the provisions in Appendix C of this
the template room, shall comply with the relevant provisions of Chapter 6 of this
standard. When the test results do not meet the requirements of this standard,
it shall find out the reasons AND take improvement measures.
5.2 On-site examination on building materials
5.2.1 When the inorganic non-metallic main building materials and
building decoration materials, which are used in civil construction
projects, enter the site, the construction organization shall check the test
report of radioactive index.
5.2.2 When the area of natural granite stone or porcelain tiles, which are used
in the interior decoration of civil buildings, is larger than 200 m2, the radioactive
index of different products and different batches of materials shall be checked
and re-examined separately.
5.2.3 When the wood-based panels and their products, which are used in
the interior decoration of civil buildings, enter the site, the construction
organization shall check the test report on the release of free
formaldehyde.
5.2.4 When the area of the wood-based panels, which are used in the interior
decoration of civil buildings, is larger than 500 m2, the free formaldehyde
emission of different products and different batches of materials shall be
checked and re-examined separately.
5.2.5 When the water-based coatings and water-based treatment agents,
which are used in the interior decoration of civil buildings, enter the site,
the construction organization shall check the free formaldehyde content's
test report of the same batch of products. When the solvent-based
coatings enter the site, the construction organization shall check the test
report of VOC, benzene, toluene + xylene, ethylbenzene content of the
same batch of products, among which the polyurethane type shall have a
test repo...