GB/T 39386-2020 in English

Analysis of the core content of the standard

This standard innovatively proposes two on-site detection methods: small-scale hood system and gas collection bag, which solves the industry pain point that custom furniture is difficult to detect in the laboratory due to its large size and complex structure. The detection objects focus on volatile organic compounds (VOC) and total volatile organic compounds (TVOC) with a boiling point of ≤260℃.

Key instrument and equipment requirements

Specific requirements of the standard The accuracy of the portable digital thermometer and hygrometer must reach ±1℃ for temperature and ±3% for humidity, and the flow error of the field test instrument must be ≤3%. It is specially stipulated that the analysis of the adsorbent Tenax GC/Tenax TA used for sampling must be completed within 14 days.

Key points for instrument calibration

• The small hood system must comply with the requirements of Chapter 5 of GB/T 32443-2015
• The gas outlet of the micro vacuum pump must be kept clean
• The purity of high-purity nitrogen must be ≥99.99%

Sample selection specifications

Detailed sampling rules are formulated for plates of different thicknesses, soft covered parts, and parts with an opening area of ＞5%. Explicitly exclude non-major release sources such as hardware, unpainted glass/stone, etc.

Recommendations for the implementation of the standard

1. Before testing, the ambient temperature must be strictly controlled at 23±2℃
2. Three nitrogen replacements are required when sampling with the air bag method to ensure background cleanliness
3. When R²＜0.90, the maximum slope method should be used to calculate the release rate
4. In case of dispute, the GB/T 31106-2014 laboratory method shall prevail

Technical evolution analysis

Compared with the 2009 version of the standard, the 2020 version adds a direct on-site measurement method, introduces the correlation coefficient R² to determine the validity of the data, and improves the detection efficiency by about 40%. However, it should be noted that on-site instruments need to be regularly compared and calibrated with laboratory methods.