Exposure from Methacrylate Polymers
Migration of Monomers from Methacrylate Based Polymers During Normal Use
The extraordinary range of properties of methacrylate based polymers means they play an essential and ubiquitous role in everyday life from your eye glass frames, contact lenses, hair sprays to dishes, toys, packaging, printing inks, tools, construction materials and car paints, to name just a few. Almost all acrylic polymers contain additives to provide the desired properties of the finished item (such as color, scratch or impact resistance, heat or UV stabilization and flame retardation), as well as small amounts of chemicals left over from their manufacture (residual monomers and process residues).
Acrylic polymers are generally of very low toxicity making them ideal for the manufacture of a wide range of medical and dental products which are intended to come into contact with the human body. The additives and monomers used in their manufacture are typically more reactive, irritating, or potentially harmful than the polymers themselves. Low migration of these smaller molecules out of the polymer under expected conditions of use, such as when packaging comes into contact with food or a person handles a product, is an important aspect of product safety.
Studies on the migration of monomers from acrylic polymers into different liquids simulating fatty food, saliva and sweat have shown that acrylic monomers (both methacrylate and acrylate) are released extremely slowly under normal conditions where the integrity of the plastic is not destroyed. Indeed, they migrate slower than from any known plastic studied to date. Since other process residues will migrate at comparable rates to acrylic monomers we can be confident that there is very low potential for exposure of consumers to chemicals migrating from acrylic during normal use. For more information, see the technical summary of Exposure to Methacrylate Polymers.
Adverse health effects are not anticipated as a result of handling methacrylate polymers and polymer-based articles under normal conditions. Indeed, a recent publication by M. Pemberton and B. Lohmann (Risk Assessment of residual monomer migrating from acrylic polymers and causing allergic contact dermatitis during normal handling and use) concluded that the risk of inducing skin allergy (Allergic Contact Dermatitis) in consumers handling polymer is extremely low despite using extremely conservative assumptions regarding conditions of exposure and use. For more information, see the technical summary.