## 2 Legislation
### Europe--European Unions' Countries  
At the European level, major authorities took the first step toward monitoring PFAS contamination in 2004. In fact, this year the European Union published a regulation of the production and commercialization of PFOS that was valid until 2019 [28]. That legal document was replaced by the \"Regulation (EU) 2019/1021 of the European Parliament and of the Council of 20 June 2019 on persistent organic pollutants\" [29], where the manufacturing, use, and placing on the market of substances listed in Annex I, such as PFOS and its derivatives C\({}_{8}\)F\({}_{17}\)SO\({}_{2}\)X (X = OH, metal salt (O-M\({}^{+}\)), halide, amide, and other derivatives including polymers, in mixtures or in articles, shall be prohibited with some exemptions. In 2008, a scientific opinion of the panel on pollutants in the food chain was issued by EFSA., focusing on PFOA, PFOS, and their salts, which are the byproducts of the breakdown of PFAS in polymers. The conclusion of the opinion was that the relative contribution of such precursors to the PFOS and PFOA environmental contamination is not yet understood [30]. Later, in 2018, prior to the TWI declaration, EFSA published the risk assessment on human health linked to the presence of PFOS and PFOA in food, underlying that \"PFOS and PFOA were detected in blood samples of almost all individuals assessed, demonstrating ubiquitous exposure\". This already suggested illo tempore the need for novel analytical methods and legislation developments [31]. In the same opinion, the state-of-the-art analytical techniques were listed. The Norwegian Environment Agency, in 2019, submitted a proposal to list PFHxS (with its salts) and PFHxS-related compounds in Annexes A, B, and/or C to the Stockholm Convention on POPs. In parallel, the Committee for Risk Assessment (RAC) contributed with the Dossier Submitter's suggested scope, which covers roughly 150 chemicals that potentially degrade to PFHxS. In parallel, the Committee for Socio-economic Analysis (SEAC) agreed that a more thorough strategy is required to address the dangers associated with products and mixes containing PFHxS, its salts, and related compounds rather than relying solely on national rules [32; 33]. Due to the advances in technologies that allow it to reach a lower level of detection and the increasing levels of contamination, on 23 February 2022, the European Commission proposed a ban on all PFASs in firefiting foams throughout the entire European Union. Such a restriction aims to counter soil and groundwater contamination as well as threats to the environment and human health. The European Chemicals Agency (ECHA) assessed the benefits and drawbacks of five possible strategies for reducing the risks posed by PFAS in firefiting foams [34]. According to \"ANNEX XV RESTRICION REPORT for Per- and polyfluoroalkyl substances (PFASs) in firefiting foams\" published in March 2022, the proposal aims to prohibit the marketing, use, and formulation of all PFAS in post-use fire-fighting foams or industry-specific transition periods [35]. After the proposals for banning PFOA, PFOS, and PFHxS on 17 January 2023, the ECHA added perfluoropentanoic acid (PFHpA) to the candidate list of compounds of very high concern due to its dangerous characteristics. Although this compound is not REACH-registered, its inclusion on the list can be seen as a preventive action for avoiding its use ad a PFAS substitute that can be in the substitutions in the future [36]. Denmark, Germany, the Netherlands, Norway, and Sweden took the most significant step in the fight against per- and polyfluoroalkyl substance contamination in Europe when they submitted a proposal to ECHA to prohibit PFAS under REACH. The five authorities found risks related to the manufacture, marketing, and use of the contaminants that are