Hundreds of chemicals (784) in dust were found in different lists from the NORMAN -SLE tree (Figure ). These NORMAN-SLE lists were selected to provide a comprehensive understanding of the types of chemicals annotated in the household dust samples. Most matches (544, of which 51 were significant) were found in the S32 REACH17 , which is a list of chemicals registered under REACH, the European Chemical Legislation that requires registration of chemicals in use above one tonne per annum . Benzocaine, benzyl butyl phthalate, and scopoletin are some examples of REACH chemicals found in household dust samples. Notably, 204 out of the 1,003 chemicals identified in this study were previously noted in the NORMAN collaborative household dust trial (S35 INDOORCT16 list ). These included plasticizers such as dibutyl phthalate, pharmaceuticals such as tramadol, benzocaine, ketoprofen, gabapentin and the fungicide carbendazim, one of the most prevalent biocides in Italian household dust samples . Furthermore, 151 chemicals were potential ingredients of cosmetics, mapping to the S13 EUCOSMETICS list, while 52 were present in the list of chemicals associated with neurotoxicity (S37 LITMINEDNEURO ), including 2,4dinitrophenol and diethyltoluamide (DEET). Additionally, 89 chemicals associated with plastic packaging (via S49 CPPDBLISTB list ) were tentatively identified, including dibutyl phthalate, and bisphenol A diglycidyl ether. The overlap of chemicals across all these lists was high ( Figure ), suggesting that most of the annotated compounds have multiple potential origins and/or reasons for interest. were in this MetOrigin class (Figure ); 366 of these overlapped. Additionally, 282 chemicals are potentially related to microbiota according to MetOrigin (Figure ). As for the NORMAN-SLE categories (Figure ), the overlap across the different PubChem TOC categories was high (Figure ).