How Should I Choose A Standard for Indoor Air Quality Testing?

Posted on September 25, 2018
by PureLiving

One day before a testing project, our clients receive a detailed preparation email which reminds them to close their doors and windows either 1 or 12 hours prior to the appointment. The time is based on the testing standard selected by our consultants based on their knowledge of your site conditions. Why is it not the same?


First, let’s talk about why we need to close the doors and windows.

Humans are spending more and more time indoor as society urbanizes. Many people spend 90% of their time indoors, especially during summer and winter when the need for air conditioning is high. Thus, closing the doors and windows before testing simulates the daily living environment, which decreases the variance of the testing data from the actual living condition.


There are certain standards for the time length of closing the doors and windows before collecting data. In China, there are two common standards:

GB50325-2010 (Code for Indoor Environmental Pollution Control of Civil Building Engineering) is issued by China Ministry of Construction. It is a mandatory standard that defines the allowable level of 5 different air components, including formaldehyde, benzene, radon, ammonia, and TVOC. The space being tested needs to be sealed off 1 hour before testing.

GB/T18883-2002 (National Indoor Air Quality Standard) is issued by China‘s National Environmental Protection Administration and the Ministry of Health. It is a stricter standard, setting a maximum level for longer exposure as recommended by the government. It regulates the level of 19 different air components, including formaldehyde, TVOC, and benzene. The space being tested needs to be sealed off 12 hours before testing to accurately represent conditions experienced every day.


There are 3 major differences between the two standards mentioned above:

1. Regulatory

The GB50325-2010 "Code for indoor environmental pollution control of civil building engineering" is mandatory, which must be met or else there will be punishments from relevant government departments.

The GB/T18883-2002 "Indoor Air Quality Standard" is optional; however, it is recommended that buildings meet the requirements for improved occupant health.


2. Scope of Application

The GB50325-2010 "Code for indoor environmental pollution control of civil building engineering" focuses on construction projects. The air pollution level refers to the number of harmful substances released by the construction and decoration materials.

The GB/T18883-2002 "Indoor Air Quality Standard" gives certain guidelines for indoor air parameter values, which can be used to evaluate the indoor environmental air quality of residential and commercial buildings


3. Parameter Benchmark

The two standards have different requirements for parameter values.

parameter chart
*Civil buildings are divided into two categories according to the different requirements of controlling indoor air quality:
Class I civil construction projects: residential buildings, hospital, nursing home, kindergartens, school classrooms, and other civil construction projects
Class II civil construction projects: office buildings, shops, hotels, cultural and entertainment places, bookstores, libraries, exhibition halls, sports complex, public transport waiting rooms, restaurants, barber shops and other civil engineering projects.




About PureLiving

PureLiving is a leading indoor environmental consulting company with a simple mission: to help our clients create healthy homes and workplaces. Our expert team of building engineers, HVAC specialists, and environmental consultants advises clients on air and water quality, mold, asbestos and lead exposure issues and helps to improve their indoor environmental quality through testing to identify sources of pollution and then eliminating them. Our total range of solutions includes pollutant testing, design and installation of cutting-edge filtration systems, monitoring, and odor and chemical reduction.

With operations in six cities across China, Hong Kong, and India, PureLiving is the industry’s provider of choice for assessment, engineering, implementation, and monitoring of indoor environmental quality. Find out more at




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