Key Takeaways & Executive Findings
- •• • Environmental chamber tests on 34 material categories (25 solid, 9 liquid) reveal that both formaldehyde and TVOC concentrations peak on day 2 post-decoration, but liquid materials decay by 70%–90% within one week, whereas solid materials decay slower, becoming the dominant long-term source. • • The simplified estimation method, validated against multi-material composite scenarios, yields acceptable errors and enables rapid air quality prediction within 2–3 hours, compared to weeks for chamber testing and complex model calculations. • • Material emission rates are classified into four grades (F1–F4) for formaldehyde (thresholds: <0.01, 0.01–0.03, 0.03–0.06, 0.06–0.12 mg·(m²·h)−1) and TVOC (thresholds: <0.04, 0.04–0.20, 0.20–0.40, 0.40–0.80 mg·(m²·h)−1), enabling standardized risk screening. • • The method addresses the disconnect between single-material compliance and whole-room exceedance ('single product qualified, overall exceedance') by incorporating area loading rates and ventilation, thus supporting proactive source control in design phases.
Abstract
To enhance the engineering practicality of pollutant pre-assessment, this study conducted environmental chamber tests for formaldehyde and TVOC emissions from 34 common decoration materials (25 solid and 9 liquid categories). Using the IndoorPACT software, variations in indoor pollutant concentrations under different material area loading rates and air change rates were simulated. Taking Harbin as a case study, concentration response ranges for various single materials under different area loading and ventilation conditions were simulated, leading to the construction of a simplified concentration prediction reference table. Results indicate that indoor pollutant concentrations from both solid and liquid materials peak on the second day after decoration, but decay rates differ significantly: liquid materials decrease by 70%–90% within about one week, and given their typically higher area loading rates in real projects, they exert a more significant impact on indoor air quality in the early post-decoration period. In contrast, solid materials decay more slowly and become the dominant long-term pollution source. The simplified estimation method based on these emission characteristics demonstrates good engineering applicability, providing effective reference for material selection, scheme comparison, and preliminary indoor air quality prediction and control in actual decoration projects.
1. Introduction
Indoor air pollution, particularly formaldehyde and total volatile organic compounds (TVOC), poses significant public health risks. These pollutants primarily originate from decoration materials and furniture, and their accumulation is exacerbated by traditional construction management that relies on post-completion testing and passive remediation. This reactive approach misses the critical window for source control during material selection and construction, leading to high pollutant loads that are difficult and costly to mitigate. Furthermore, existing material emission standards are disconnected from indoor air quality standards, as they evaluate individual products in isolation, ignoring the cumulative effect of multiple materials in a real room. This often results in the paradox of 'single product compliance but overall room exceedance,' a persistent challenge in indoor environmental quality management.
To address this bottleneck, this study leverages a comprehensive dataset of environmental chamber emission tests from 34 common decoration materials. By employing the IndoorPACT simulation tool, we systematically analyze the concentration responses under varying material area loading rates and ventilation conditions. The outcome is a simplified estimation method and a visual reference table that allows engineers to predict indoor pollutant concentrations within hours, rather than weeks, without complex modeling. This approach bridges the gap between material-level testing and room-level air quality prediction, enabling proactive design-phase interventions and aligning with the requirements of green and healthy building standards.
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SUN Mingzhuo, SHEN Chao, BI Xuesong, WANG Fang, DENG Weicai (2026). Simplified Estimation of Indoor Air Quality Based on Material Pollutant Emission Rates and Concentration Responses. Chinese Journal of Environmental Engineering. https://doi.org/10.12030/j.cjee.202507038
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Frequently Asked Questions
How does the simplified estimation method account for the dynamic decay of emissions from solid versus liquid materials, and what are the implications for long-term indoor air quality management?
The method incorporates distinct decay profiles: liquid materials show a rapid decline of 70%–90% within one week, while solid materials decay more slowly, sustaining emissions over months. This is critical for predicting both short-term peak exposures and long-term baseline concentrations. For engineering practice, it implies that ventilation strategies should be intensified immediately after decoration to mitigate the initial peak from liquids, while source control for solids (e.g., using low-emission boards) is essential to prevent chronic exposure.
What are the specific emission rate thresholds used for material classification, and how do they correlate with the probability of exceeding indoor air quality limits in a typical room?
Emission rates are classified into four grades (F1–F4) for formaldehyde and TVOC. For formaldehyde, F1 is <0.01 mg·(m²·h)−1, F2 0.01–0.03, F3 0.03–0.06, and F4 0.06–0.12 mg·(m²·h)−1. For TVOC, thresholds are <0.04, 0.04–0.20, 0.20–0.40, and 0.40–0.80 mg·(m²·h)−1. The correlation with room-level exceedance depends on area loading and ventilation; however, materials in F3 and F4 grades are likely to cause exceedance when used in typical loading scenarios, as indicated by the simulation results.
How does the method handle the combined effect of multiple materials in a real room, and what is the margin of error compared to detailed simulation?
The method uses a superposition approach based on individual material emission rates and their respective area loading rates. Validation against multi-material composite scenarios shows that the estimation error is within acceptable engineering tolerance (exact values not specified in the text, but stated as 'acceptable'). This allows for quick screening of material combinations to identify potential exceedances before construction.
What are the limitations of the simplified method in terms of environmental conditions (temperature, humidity) and material aging, and how can it be adapted for different climates?
The method is based on standard chamber tests at controlled conditions (typically 23°C, 50% RH). It does not explicitly account for variations in temperature and humidity, which can significantly affect emission rates. For different climates, correction factors may be needed. The study was conducted in Harbin, a cold region, and the reference tables are specific to typical indoor conditions. Users should apply caution when extrapolating to extreme climates and consider adjusting for seasonal variations.
How does this method align with current Chinese standards (JGJ/T 436—2018, GB 50325—2020) and green building certification requirements, and what is its role in the design process?
The method directly supports the pre-assessment requirements of JGJ/T 436—2018 and GB 50325—2020, which mandate pollutant concentration prediction during design. It also provides a practical tool for earning credits under green and healthy building standards (GB/T 50378—2019, T/ASC 02—2016) that require demonstrating pollutant control. By enabling rapid estimation, it facilitates iterative design optimization, allowing architects to select materials and ventilation strategies that ensure compliance from the outset.
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