| Résumé : |
Formaldehyde has no purpose in leather, and its presence is not prohibited by government regulation. However, due to its role in process chemical manufacture and preservation, formaldehyde is normally detected in leather at residual concentrations which exceed the very stringent limits enforced by automotive companies and leather product manufacturers. Like formaldehyde, NMP (n-methyl pyrrolidone) has no function in leather. However, it offers unique benefits as a solvent in the production of polyurethane (PU) finish systems, and significant residual concentrations have been detected in upholstery and shoe upper leathers coated with PU-based formulations. This means that the recent addition of NMP to California Proposition 65 will force the leather industry to seek alternative finish formulation technology unless a relatively high Safe Harbor level is quickly established. In addition, the listing of OPP (ortho-phenyl phenol) on Proposition 65 recently became effective. A Safe Harbor level has not yet been determined for OPP, forcing many suppliers to the Californian market to abandon the use of a very effective and widely used fungicide that is endorsed by the US military. A disturbingly small range of alternatives remain. These obstacles to the use of high performance retanning agents, some organic pigments, and PU finishes, together with the provisionally diminished range of acceptable fungicides is being compounded by continued focus on chromium by regulatory bodies in both Europe and the USA. This paper reveals and investigates the scientific flaws behind these latest environmental constraints. |
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An update on environmental constraints in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. XCVII, N° 12 (12/2002)
