Development of a multi-VOC reference material for quality assurance in materials emission testing

Abstract

Emission test chamber measurement is necessary to proof building materials as sources of volatile organic compounds (VOCs). The results of such measurements are used to evaluate materials and label them according to their potential to emit harmful substances, polluting indoor air. If only labelled materials were installed indoors, this would improve indoor air quality and prevent negative impacts on human health. Because of the complex testing procedure, reference materials for the quality assurance are mandatory. Currently, there is a lack of such materials because most building products show a broad variation of emissions even within one batch. A previous study indicates lacquers, mixed with volatile organic pollutants, as reproducible emission source for a wide range of substances. In the present study, the curing of the lacquer-VOC mixture inside micro-chambers was optimised. Therefore, the humidity and the chamber flow were varied. Typical indoor air pollutants with a wide range of volatilities, for example, styrene, n-hexadecane, dimethyl and dibutyl phthalate were selected. It turned out that, under optimised curing parameters inside the micro-chamber, their emission can be reproduced with variations of less than 10 %. With this, a next important step towards a reference material for emission testing was achieved.

Volatile organic compounds from building products—Results from six round robin tests with emission test chambers conducted between 2008 and 2018

“…Sampling had to be conducted seven days after loading. The duration of seven days (in contrast to the normative testing of 28 days) was chosen for two reasons: On the one hand, the testing period for the participants should be as short as possible, and on the other hand, the emission profile at that time has a relatively consistent profile as shown by Nohr et al 7,8 …”

Application of a novel reference material in an international round robin test on material emissions testing

“…Air sampling was carried out on Tenax ® TA tubes followed by thermal desorption and GC/MS analysis on an Rxi‐5 mseconds column (RESTEK GmbH, Bad Homburg a.d.H., Germany, 60 m, 25 mm, 0.25 μm). Analyte separation, identification, and quantification were performed based on the procedure described by Nohr et al.…”

“…For the preparation of the RRT samples, 12 L of the lacquer system were prepared and mixed according to the scheme shown in Figure . Its composition was based on the findings published by Nohr et al. In summary, 20 g of the mixture was weighed into 500× large polystyrene (PS) Petri dishes (D 94 mm, surface area 69.4 cm²), while 2.5 g of the mixture was weighed into 40× small PS Petri dishes (D 34 mm, surface area 9.1 cm²).…”

“…The number of 7 days was chosen for two reasons: on the one hand the testing period for the participants should be as short as possible, and on the other hand the emission profile at that time is not significantly affected by experimental parameters (e.g. air chance rate, loading, air velocity above material surface), as was shown by Nohr et al.…”

“…The participants had to identify and quantify VOC emissions from a test material within their own test facilities. For this purpose, a reference sample based on a lacquer system as described by Nohr et al was used. It consisted of a clear, glossy water‐based lacquer (WGC‐lacquer) proven to have inherently low VOC emissions.…”