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.