Fraunhofer WKI, Department of Material Analysis and Indoor Chemistry, Bienroder Weg 54 E, 38108 Braunschweig, Germany.
Fraunhofer WKI, Department of Material Analysis and Indoor Chemistry, Bienroder Weg 54 E, 38108 Braunschweig, Germany.
Environ Int. 2021 Oct;155:106590. doi: 10.1016/j.envint.2021.106590. Epub 2021 May 6.
It has been known for a long time that incomplete combustion processes produce by-products that are harmful to human health. Particularly high concentrations of such by-products can arise in indoor environments when operating open flames without venting. The emission behavior of many combustion sources, including candles, has already been examined in detail. However, to date there are no studies in which the chemical composition of the candles is known exactly or where the candles were specifically manufactured for comparative measurements. In this respect, the study presented here, which was designed in collaboration with candle manufacturers and fragrance houses, demonstrates new insights into the emissions of burning candles depending on their composition. All investigations were carried out under controlled climatic conditions in an 8 m stainless steel chamber. Combinations of four different fuels (waxes) and five different fragrances in addition to one set of unscented control candles were examined. This resulted in 24 experiments, 20 with scented candles and four with unscented candles. The typical combustion gases carbon monoxide, carbon dioxide and NO, organic compounds, such as formaldehyde, benzene, and polycyclic aromatic hydrocarbons, PM and ultrafine particles were monitored in the chamber air and the emission rates were determined. The data were statistically evaluated using parametric and non-parametric methods as well as hierarchical cluster analysis. Exposure scenarios typical for indoor environments were calculated from the emission rates and the results were compared with indoor guidance and reference values. As expected, a multitude of gaseous and particulate emissions were detected. These were typical combustion products as well as evaporated constituents of the fragrance mixtures. In most cases, the calculated indoor concentrations were well below the respective guidance and reference values. The exceptions observed in some cases for nitrogen dioxide, acrolein and benzo[a]pyrene are discussed critically.
长期以来，人们已经知道不完全燃烧过程会产生对人类健康有害的副产物。当没有通风的情况下操作明火时，室内环境中特别容易出现这种副产物的高浓度。许多燃烧源的排放行为，包括蜡烛，已经被详细研究过。然而，迄今为止，还没有研究精确地知道蜡烛的化学成分，或者为了进行比较测量而专门制造蜡烛。在这方面，本研究通过与蜡烛制造商和香料公司合作，展示了根据蜡烛成分燃烧时排放的新见解。所有研究都是在一个 8 米长的不锈钢室内，在受控气候条件下进行的。除了一套无味的对照蜡烛外，还检查了四种不同燃料（蜡）和五种不同香料的组合。这导致了 24 项实验，其中 20 项是有香味的蜡烛，4 项是无味的蜡烛。在室内空气中监测了典型的燃烧气体一氧化碳、二氧化碳和 NO、有机化合物，如甲醛、苯和多环芳烃、PM 和超细颗粒，并确定了排放率。使用参数和非参数方法以及层次聚类分析对数据进行了统计评估。从排放率计算了典型的室内环境暴露情景，并将结果与室内指导值和参考值进行了比较。正如预期的那样，检测到了大量的气态和颗粒状排放物。这些是典型的燃烧产物以及香料混合物蒸发的成分。在大多数情况下，计算出的室内浓度远低于各自的指导值和参考值。对于二氧化氮、丙烯醛和苯并[a]芘等在某些情况下观察到的例外情况，进行了批判性讨论。
