Emission characteristics and probabilistic health risk of volatile organic compounds from leather sofa

Furniture is identified as a vital volatile organic compound (VOC) emission source in the indoor environment. Leather has become the most common raw and auxiliary fabric material for upholstered furniture, particularly with extensive consumption in sofas, due to its abundant resources and efficient functions. Despite being widely traded across the world, little research has been conducted on the VOCs released by leather materials and their health risk assessment in the indoor environment. Accordingly, this study investigated the VOC emissions of leather with different grades and the health risk of the inhalation exposure. Based on the ultra-fast gas phase electronic nose (EN) and GC-FID/Qtof, the substantial emissions of aliphatic aldehyde ketones (Aks), particularly hexanal, appear to be the cause of off-flavor in medium and low grade (MG and LG) sofa leathers. The health risk assessment indicated that leather materials barely pose non-carcinogenic and carcinogenic effects to residents. Given the abundance of VOC sources and the accumulation of health risks in the indoor environment, more stringent specifications concerning qualitative and quantitative content should be extended to provide VOC treatment basic for the manufacturing industry and obtain better indoor air quality.

Gaseous products generated from polyethylene and polyethylene terephthalate during ultraviolet irradiation: Mechanism, pathway and toxicological analyses

The generation of various degradation products from microplastics (MPs) has been confirmed under ultraviolet (UV) irradiation. The gaseous products, primarily volatile organic compounds (VOCs), are usually overlooked, leading to potential unknown risks to humans and the environment. In this study, the generation of VOCs from polyethylene (PE) and polyethylene terephthalate (PET) under UV-A (365 nm) and UV-C (254 nm) irradiation in water matrixes were compared. More than 50 different VOCs were identified. For PE, UV-A-derived VOCs mainly included alkenes and alkanes. On this basis, UV-C-derived VOCs included various oxygen-containing organics, such as alcohols, aldehydes, ketones, carboxylic acid and even lactones. For PET, both UV-A and UV-C irradiation induced the generation of alkenes, alkanes, esters, phenols, etc., and the differences between these two reactions were insignificant. Toxicological prioritization prediction revealed that these VOCs have diverse toxicological profiles. The VOCs with the highest potential toxicity were dimethyl phthalate (CAS: 131-11-3) from PE and 4-acetylbenzoate (3609-53-8) from PET. Furthermore, some alkane and alcohol products also presented high potential toxicity. The quantitative results indicated that the yield of these toxic VOCs from PE could reach 10² μg g^-1 under UV-C treatment. The degradation mechanisms of MPs included direct scission by UV irradiation and indirect oxidation induced by diverse activated radicals. The former mechanism was dominant in UV-A degradation, while UV-C included both mechanisms. Both mechanisms contributed to the generation of VOCs. Generally, MPs-derived VOCs can be released from water to the air after UV irradiation, posing a potential risk to ecosystems and human beings, especially for UV-C disinfection indoors in water treatments.

Comparative analysis of very volatile organic compounds and odors released from decorative medium density fiberboard using gas chromatography-mass spectrometry and olfactory detection

VVOCs with a retention range below C₆ have become one of the main indoor pollutants that negatively affect human health. Most studies have focused on the emission of VOCs from furniture and decorative materials, seldom consider VVOCs. To close this gap, a 15-L environmental chamber, combined with multi-absorbent tube, was used for gas sampling. Emissions of VVOCs and odors released from decorative medium density fiberboard (MDF) were measured using gas chromatography-mass spectrometry and olfactometry detection. The results demonstrated that multi-absorbent tubes had excellent capture capacity for low-molecular-weight VVOCs. Thickness and decorative materials had conspicuous effects on VVOCs and odor emissions. The total VVOCs (TVVOC) from 18-mm decorative MDF was consistently higher than that of 8-mm samples. The major VVOCs from these decorative MDF were alcohols, esters and ketones, which were the major odor contributors with high odor intensity values. VVOCs concentration generally increased as thickness increased, but it decreased after decorative treatment. Fruity and alcohol-like were the main odor impressions of 8-mm MDF, whereas sweet and fruity were the major odor impressions of 8-mm polyvinyl chloride decorative MDF (PVC-MDF) and melamine impregnated paper decorative MDF (MI-MDF). Fruity was the main odor impression of 18-mm decorative MDF. The overall odor intensity increased and the major odor impression may differ when thickness was changed. Both the MI and the PVC decorative materials blocked some odor emissions but did so to a greater extent with the former than with the latter. Identification and analysis of the composition of VVOCs can supplement a database structure network of volatile pollutants and establish a novel and feasible method to investigate low-molecular-weight substances from wooden materials and their products.

Indoor Air Quality: Assessment of Dangerous Substances in Incense Products

Indoor air pollution has obtained more attention in a moment where "stay at home" is a maximum repeated for the entire world. It is urgent to know the sources of pollutants indoors, to improve the indoor air quality. This study presents some results obtained for twelve incense products, used indoors, at home, and in temples, but also in spa centers or yoga gymnasiums, where the respiratory intensity is high, and the consequences on health could be more severe. The focus of this study was the gaseous emissions of different types of incense, performing a VOC screening and identifying some specific VOCs different from the usual ones, which are known or suspected to cause severe chronic health effects: carcinogenic, mutagenic, and reprotoxic. Thirteen compounds were selected: benzene, toluene, styrene, naphthalene, furfural, furan, isoprene, 2-butenal, phenol, 2-furyl methyl ketone, formaldehyde, acetaldehyde, and acrolein. The study also indicated that incense cone type shows a higher probability of being more pollutant than incense stick type, as from the 12 products tested, four were cone type, and three of them were in the group of the four higher polluters. Benzene and formaldehyde presented worrying levels in the major part of the products, above guideline values established by the WHO. Unfortunately, there are no limit values established for indoor air for all the compounds studied, but this fact should not exempt us from taking action to alert the population to the potential dangers of using those products. From this study, acetaldehyde, acrolein, furfural, and furan emerge as compounds with levels to deserve attention.

GC-FID and Olfactometry-Assisted Assessment of Odors from Polymeric Foams under Normal and Repeated-Use Conditions

Polymeric foams are the primary components of upholstered furniture, and their emissions play a decisive role in the acceptability of the final furniture product. This study is focused on passive emissions and odors from commercial foams under normal and repeated-use conditions. Six different types of foams, viz., highly elastic foam K5040, standard PU foam N5063, bonded polyurethane foam R100, viscoelastic foam V5020, self-extinguishing foam KF5560, and foam rubber, were used. The samples were collected at the intervals of 72 hours and 672 hours (28 days) to identify the odors due to chemical reactions in the material or slowly released due to its porous structure. Additionally, repeated-use studies were done to understand the effect of prolonged usage/natural ageing on emitted odors from the foams. The samples were tested as per ČSN EN 13 725 (2005) and ISO 16000-6 (2011) criteria using GC-FID (gas chromatography-flame ionization detector) and olfactometry. The most unpleasant substance was found to be nonanal, with an average score of -4 (unpleasant). A total of 23 compounds were identified (5 unidentified) using olfactometry; however, only 11 of them were confirmed by GC-FID-based testing. Any new compound or increase in odor intensity was not observed in long-term measurements and simulated repeated-use conditions.