![]() Semi-refined waxes have up to 1.5–3% oil, while scale and slack waxes have even more oil, up to a common maximum of 35–40% ( Freund et al., 1983 Kumar et al., 2007). Fully refined waxes have oil contents < 0.5–0.75%. Most of the petroleum waxes sold commercially however, are a mixture of “normal” (straight chained) and “iso” (or branched) alkanes with varying levels of purity. They have a higher molecular weight and are generally darker, more viscous, denser, tackier and more elastic than pure paraffins ( Cottom, 2000). Microcrystalline waxes instead, are produced by de-oiling petrolatum, as part of the petroleum refining process and contain a much higher percentage of branched and naphthenic hydrocarbons, in addition to normal alkanes ( Srivastava et al., 1993 Mansoori et al., 2004). Paraffin waxes are typically obtained as a by-product during the production of lubricating oils and mainly consist of saturated long-chain hydrocarbons, ranging from C 18 to C 60, and predominantly greater than C 25 ( Cottom, 2000). Most producers offer three distinct types of petroleum waxes: paraffin waxes, which are characterized by large, well formed crystals microcrystalline waxes (also known as microwax), which have higher melting points and smaller irregular crystals and petrolatum, also known as petroleum jelly or jelly wax ( Warth, 1956 Petersson et al., 2008). They appear as creamy white to dark yellow or pale brown water-insoluble substances, generally solid at room temperature but highly viscous at moderate temperatures ( Moore & Munger Marketing Inc., 1995). Petroleum waxes are crude oil derivatives primarily consisting of a mixture of hydrocarbons with typical melting points comprised between 35 and 95☌ ( Buchler and Graves, 1927 Mansoori et al., 2004). Petroleum waxes are by far the most important in terms of volume produced and economic impact, accounting for 85–90% of the global wax consumption, although demand for synthetic and vegetable waxes has been growing steadily in recent years ( Kline & Company, Inc., 2010). Other types of industrial wax include synthetic waxes produced by a series of chemical reactions (e.g., through the Fischer-Tropsch process, or using alpha-olefin and polyethylene waxes), waxes of animal origin (e.g., beeswax, chinese wax, tallow, lanolin) and vegetable waxes, such as candelilla, carnauba, castor, and soy wax ( Bennett, 1963 Casadei et al., 2010). Fossil-based waxes comprise mineral waxes (such as montan wax derived from coal and ozokerite) and petroleum waxes (petrolatum, paraffin, and microcrystalline waxes), also known as hydrocarbon waxes. The market is mainly segmented into bio-based, synthetic, and fossil-based waxes. The global production of industrial waxes currently amounts to 4.79 million tons, with a market size valued at 6.7 billion USD and an expected annual growth of 1.5–2%, driven mainly by increasing demand for single-use packaging applications ( Wei, 2012 Grand View Research, Inc., 2017). Pending further investigations on the potential hazard that this kind of pollution is posing to marine ecosystems, we suggest a careful and more stringent revision of the policies regulating discharges of these products at sea. Starting from the description of a large stranding event occurred along the Italian coasts in 2017, we review the existing knowledge and regulatory framework and urge the relevant authorities to address this issue, showing that wax pollution is creating evident damages to the European coastal municipalities. ![]() According to Annex II of the MARPOL regulation, petroleum waxes are classified as “high viscosity, solidifying, and persistent floating products,” whose discharge at sea of tank-washing residues is strictly regulated, but currently permitted within certain limits. ![]() Ingestion by marine organisms is occasionally documented in the scientific literature and mass beaching events are frequently reported along the European coasts, with obvious detrimental consequences to the local communities that have to manage the clean-up and disposal of this substance. 3ENEA-Marine Environment Research Center, La Spezia, ItalyĪmong the various materials that make up marine debris, lumps of petroleum waxes such as paraffin and microcrystalline wax, are regularly found on beaches worldwide, although not included in the current definition of marine litter.2Instituto Español de Oceanografía-Centro Oceanográfico de Baleares, Palma de Mallorca, Spain. ![]() 1Institute of Marine Sciences - National Research Council (ISMAR-CNR), La Spezia, Italy.Giuseppe Suaria 1,2 * Stefano Aliani 1 Silvia Merlino 1 Marinella Abbate 3 ![]()
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