Stability of Isocyanates Sampled in Fire Smokes

Inhalation of airborne isocyanates is associated with acute asthma attacks and inflammation in the respiratory tract as well as cancer. These highly reactive compounds are used as monomers in various applications such as foams for insulation materials and upholstery furniture and are therefore commonly found in fire smoke from insulation materials, such as rigid polyisocyanurate (PIR) foams. Consequently, there is an increasing concern regarding the potential adverse health effects they may cause during this type of exposure. The aim of this study was to investigate the stability of generated isocyanates from aerobic pyrolysis of PIR after sampling in the derivatization solution as well as after sample preparation to establish the optimal storage conditions and rate of degradation. Both airborne and particle-bound isocyanates were collected, using dibutylamine as derivatization agent in a midget impinger and impregnated filter after the impinger. The rapid degradation of the generated isocyanates after sampling emphasizes the need for a prompt sample preparation and analysis, in particular for the collected mono-isocyanates, as the concentration decreased by 50% within 4–8 h

Fractionation of extracts from paper and board food contact materials for in vitro screening of toxicity

Paper and board used as food contact materials (FCMs) are chemically complex matrices, partly due to the naturally occurring substances in paper and board, but also due to the chemical treatment of the paper used to make it suitable for food contact. In order to assure the safety of packaging materials, information on the exposure as well as on the toxicity of substances in the packaging must be obtained. This study describes a comprehensive method for the extraction and fractionation of substances present in paper and board FCMs for further investigation by in vitro testing and chemical analysis. The extraction efficiency and the fractionation process were validated by determining recoveries in extracts from paper and board fortified with five surrogates of known concentration. The recoveries for the five surrogates were between 20% and 104% in the raw extract and between 21% and 109% after extraction and fractionation. The fractionation both reduces the number of compounds to be identified and works as a sample clean-up by reducing matrix effects. Raw extracts and fractions from two paper and board FCMs were furthermore tested in the aryl hydrocarbon receptor (AhR) reporter gene assay. Both raw extracts and two of the fractions of the raw extracts gave a positive response in the AhR assay. The strategy of extraction followed by fractionation offers a powerful tool in order to make the workflow for screening FCMs for potentially adverse effects more efficient

Analytical and effect-based methods available for the environmental monitoring of endocrine disrupting compounds at the EU scale

International audienceThe Partnership for the Assessment of Risks from Chemicals (Marx‑Stoelting et al., 2023) includes a pilot project for the establishment of environmental monitoring that focusses on per- and polyfluoroalkyl substances (PFAS) and endocrine disrupting compounds (EDCs). Our ambition for EDCs is to contribute to the first EU baseline in multiple environmental compartments and to identify new key EDCs present in the environment. We intend to integrate approaches based on target analysis, non-target and suspect screening as well as effect-based methods (batteries of multi-receptor in vitro and in vivo bioassays), including their combination in effect-directed analysis (EDA) to identify major toxicants in prioritised samples. A comprehensive list of EDCs was compiled, based on previous assessments by regulatory bodies at EU and national level (e.g. (http://edlists.org) and additional potential EDCs (hormones, bisphenols, etc.), including inputs from ECHA. Furthermore, all substances in the NORMAN SusDat database (https://www.norman-network.com/nds/susdat/) were screened using the EDC prediction models of the (QSAR) VEGA platform (https://www.vegahub.eu/about-qsar/), and the EDC active compounds were added. The final list contained approximately 7300 chemicals. Further information was added, such as physico-chemical properties, functional groups for chemical analysis, modes of action for the application of bioassays, relevant matrices for monitoring, use sectors.In order to relate the list of EDCs to analytical methods, the compounds on the list were assigned to chemical classes. We worked with 75 chemical classes and assigned invidual compounds according to their chemical structure and SMILES automatic recognition. This information was compiled through a collaborative work of the PARC T4.2 EDC group. Concerning the effect-based methods, a previous review was used to list key information required, such as type of endpoints, species, adverse outcome pathways, thresholds, chemical classes, matrices etc. (Carrere et al., 2021). We have obtained a first comprehensive picture of potential applications of target and suspect screening as well as in vitro and in vivo bioassays for the quantification/detection of EDCs. This work highlights compounds and chemical classes still poorly studied and/or environmental matrices inadequately monitored. Another outcome is a restricted list of standardized methods/assays implementable for routine monitoring. This information will be used to prepare focused and cost-effective monitoring campaigns within this PARC pilot project.PARC T4.2 EDC group : A. Araja, L. Ahrens, S. Buchinger, C. Coscolla, A. Covaci, M. Creta, G. Dervilly, B. Dewitte, D. Dvorakova, R. Duca, J.P. Ghestem, J. Grimalt, C. Kech, M. Krauss, T. Kosjek, A. Lopez, S. Maletz, C. Moyano, M. Nicolas, J. Pulkrabova, P. Rostkowski, G. Thorsén, J. Trontelj, E. Van Hoeck, R. Duca, M Schlüsener, E. Vermeirssen, J. Viidanoj