Fungal growth on a hemp-flax-cotton biobased insulation materials and their potential to emit microbial volatile organic compounds
Building and Environment
In: Building and Environment, article 115076, 2026.
Abstract
Bio-based insulation materials contribute to building decarbonization and good hygrothermal performance. However, in humid conditions, they can promote fungal growth and the emission of mVOCs, affecting indoor air quality. The aim of this study is to assess the influence of aging on the susceptibility of bio-based materials to promote fungal growth and VOC emissions, and to investigate potential mVOC emissions. To this end, a hemp-flax-cotton insulation material was subjected to a 3-month accelerated aging process under alternating humidity cycles. The material was exposed to weekly dry (11 ± 4%) and humid (60 ± 2%) conditions at 25 ± 0.8 °C. Results showed strong fungal proliferation on both native and aged materials, with spore concentration reaching 100–1000 times the initial inoculum. The material was identified as very low VOC emitter in its native state. Aging did not significantly modify the overall VOC emission profile. During 30 days of incubation, emissions of 74 VOCs decreased, whereas 10 newly detected compounds (1–13 µg m−2 h−1) appeared between days 7 and 9, peaked on day 9, and then progressively declined, suggesting fungal metabolic degradation of the material.
Verbatim author abstract reproduced from the publisher record under CC BY 4.0.
FLEC use
Direct FLEC measurements
The publisher's method text states that VOC emissions from native and aged insulation samples were characterised with a FLEC having a 177 cm² surface area.