As of early January 2025, PFAS are subject to Proposition 65, the Californian law regulating the presence of chemicals in products marketed in the State. It is a pity, however, that the Californian legislator has drowned such as boundaries in the rule that put many more leathers out of bounds than they deserve.
Where PFASs are found
According to what UNIC – Italian Tanneries summarizes, “PFAS (per- and polyfluoroalkyl substances) are a class of artificial chemical compounds that contain high quantities of fluorine bound to carbon atoms”. Due to their properties, in recent industrial history they have been used “in the production of nonstick pans, in medical devices and even in pizza boxes and baking papers”. While “in the tanning industry, they have been used in the past for water-repellent and stain-resistant treatments”. OK. Returning to Californian affairs, Proposition 65 calls for a declaration of “intentional use”. And this is where the leather problems begins.
The loopholes in Californian law
The problems are twofold, denounces the association adhering to Confindustria Moda Accessori. Firstly, “unlike in other sectors such as textiles”, PFAS can be included in the leather in ways that escape the tanner’s awareness. In which way? They may “be present in very small amounts (i.e. below the threshold above which the European standard requires them to be reported, ed.) in finishing compounds or as non-sticking agents”. Or, to give another example, they may be found “in chromium salts obtained from the recycling of electroplating baths”. Moral: Proposition 65 requires tanneries to control substances beyond their material possibilities.
But the problems do not end there
There are two problems, we said. One concerns intentionality, the second measurement:
- in California they demand that the concentration of total organic fluorine be within 100 milligrams per kilo until the end of 2026.
- Easier said than measured.
- PFAS are about 5,000 substances, yet it is only possible to identify about a hundred of them, writes UNIC. In order to assess their total presence, the Total Organic Fluorine research criterion has been adopted: this assumes that all organic fluorine comes from poly – and per – fluorinated substances.
The matter does not end there. While there are no standardized methods, many laboratories also include inorganic fluorine in detecting “total fluorine”. Which is “widespread’”and “present in varying proportions in products of mineral origin (bentonite, kaolin and dolomite) and consequently in some of their derivatives, which are regularly used in the tanning industry, such as hydrated lime and magnesium oxide”. It is clear that, on these assumptions, many leathers would come out of laboratory tests not with a “pass”, but punished by a “fail”. A huge problem: there are likely to be blocked matches due to “fake results” that have nothing to do with PFAS.
The Ars Tinctoria analysis laboratory has dedicated a study to the subject: click here to read it
