Industrial Exposure

Exposure TO Methacrylates

There are no known major natural sources of methacrylate esters. Exposure to the monomers in the concentrated state occurs primarily in the workplace. Because these are reactive materials they are handled under strictly controlled conditions when they are manufactured and processed. Workers are trained and provided with the equipment needed to control exposure. In manufacturing/processing, chemical industry operators are responsible for the production of the esters or polymers, while downstream processors make the dispersions or other compounded or fabricated items.

Regarding exposure, the end products produced from these monomers fall into two categories, those used by professional applicators and those that are meant for the consumer market.

The materials intended for the professional applicators can include uncured resins that are used as adhesives or finish coatings, glues or fillers to repair plastic articles, some health care products such as dental appliances or fillings. Professionals who use these materials are provided with the information on how to use them safely. The amounts of monomer in medical products are regulated. The final products produced or repaired with these materials contain very low levels of unreacted monomer.

Consumer exposure to monomers from finished products made with the polymers is very low and both oral and dermal exposures are considered to be negligible. The vast majority of products available to consumers are made from cured resins. Examples include: coatings or surface finishes, glass substitutes, molded fixtures or appliance parts, toys, packaging, sporting equipment, etc. In some products like glues or cements, varnishes or other finishes, consumers may be exposed to residual monomers until the adhesive or coating dries. For these materials, the package labels give instructions on safe use. These instructions include use in a well ventilated area and preventing contact with the skin. Use in artificial nail products and other non-medical/dental applications involving direct skin/nail contact with the liquid monomer is not recommended or supported by the MPA member manufacturers. In summary, consumer exposure to liquid monomer is unlikely unless they intentionally use professional/DIY or hobbyist products that contain significant levels of liquid monomer. Consumer exposure is primarily only to the extremely low levels of residual monomer in fabricated consumer products.

See the technical overview of Exposure to Methacrylates.

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.