Aarhus Universitets segl

No.493: Non-target screening - identification of new chemicals in the indoor environment

Fauser, P., Zhu, L., Sanderson, H., Mikkelsen, L. &, Vorkamp, K. 2022. Non-target screening - identifikation af nye kemikalier i indemiljøet, Aarhus Universitet, DCE – Nationalt Center for Miljø og Energi, 82 s. - Videnskabelig rapport nr. 493. http://dce2.au.dk/pub/SR493.pdf


Twelve dust samples from three daycare institutions in Denmark, with children between zero and six years of age, were collected in September 2020 and February 2021. The institutions also participated in the previous project ”Indeklima i daginstitutioner” in 2019. A suspect list was constructed of 41 chemicals that met one or more criteria of being known or suspected endocrine disrupters, neurotoxicants, carcinogens or allergenes. Using suspect screening, 29 of the 41 chemicals were identified in the dust samples. In addition, brominated flame retardants were determined using an existing target GC-MS target method. The same dust samples were analyzed for structurally similar, unknown chemicals using non-target screening.

The chemical analysis only aimed at identification, not quantification of the chemicals, in order to investigate abundance and type of hazardous chemicals. Selected identified chemicals that did not have a GHS-hazard classification were included in a hazard assessment.

Of the 41 chemicals on the suspect list, 29 were identified in dust, including 12 softeners, five flame retardants, two bisphenols, three UV filters, four plastic additives and three parabens. Several of the compounds, e.g. phthalates and the brominated flame retardant DecaBDE are banned or have restricted use. The non-target screening of not-known/not-expected chemicals tentatively identified 15 chemicals, however with higher uncertainty; Four plasticisers, two phosphorous flame retardants, two fragrance compounds, one polyaromatic hydrocarbon (PAH) and two aromatic nitrocompounds. In addition, four polychlorinated biphenyls (PCBs) were tentatively found, but need verification with analytical standards.

The hazard assessment of identified substances without any GHS-classification showed that risks for humans are probably limited, however, this assessment was not directed specifically at children. The chemicals from the non-target screening analysis could not unambiguously be documented to be carcinogenic, neurotoxic, reprotoxic or allergenic due to lack of toxicity data on the chemicals. PCBs are, however, classified as carcinogenic.

Identification with non-target screening is associated with considerable uncertainty. Since several of the identified chemicals have analytical standards, it is recommended that the tentative identification is verified with targeted analysis. The identified chemicals with the most pronounced health effects can then be included in a more targeted quantification and risk-analysis. The purpose of this project was to highlight lesser known chemicals in dust, that potentially constitute a health risk and that could be investigated further. It was not the purpose to give guidelines to reduce or remove the presence of chemicals in the indoor environment. Here we refer, e.g. to the ”Indeklima i daginstitutioner” project. The project results will be disseminated to the institutions, the municipality and the Danish EPA and can be considered in initiatives to create a safe and healthy indoor environment for children in Denmark.