Industrial Hygiene
Methacrylates And Do-It-Yourself Products
There are many uses of products containing methacrylate-based (acrylic) polymers in consumer, semi-professional, or Do-It-Yourself (DIY) applications. In contrast to the handling of liquid methacrylate monomers which requires special precautions, routine handling of high molecular weight methacrylate-based polymer products generally require no special procedures.
The precise level of residual monomer in the polymer is considerably influenced by the production processes and conditions used. There are three basic types; emulsion, bulk and solution polymers. Emulsion polymers are frequently used in paints, adhesives, or coatings for paper or textiles and have the lowest residual monomer level. Bulk polymers are typically provided in the form of a rigid article, either molded, extruded or in sheet form and have very low residual monomer levels. Common examples of solution polymers are varnishes, adhesives or coatings and may be supplied in a solvent or contain low levels of residual solvent. Solution polymers generally have the highest residual monomer levels, which are still relatively low. The levels of monomer residues in all of these polymer types should not typically require safety and handling procedures beyond those generally regarded as suitable for the types of tasks involved.
It should be recognized that all acrylic polymers decompose to some extent at elevated temperatures. Since typical fabrication or polymer treatment processes may involve elevated temperatures, the user is recommended to follow very closely any safe handling guidance provided by the manufacturer of these products.
Semi-professional, consumer, DIY and hobbyist applications that involve the use of acrylic polymers in combination with liquid methacrylate monomer(s), solvents or other chemicals will require the user to assess the combination of products being used. This could include contacting the supplier/manufacturer(s) of the other chemicals for any additional safe handling guidance not already covered by the label instructions or (material) safety data sheets ((M)SDS) provided. Depending upon the product composition, this may include specific recommendations to avoid skin contact by the wearing of gloves and/or to avoid inhalation of vapors by ensuring good ventilation or the wearing of respiratory protection. These unreacted liquid chemicals should never be poured down drains or discarded in domestic or public waste, but instead sent to a chemical-waste collection site.
Methacrylates And Skilled Trade
Some end-products intended for use by skilled trade or professional users contain relatively high proportions of unreacted monomer. These are often referred to as monomer/polymer systems. Examples include certain reactive cements, monomer based paints etc. In contrast to the industrial setting where the conditions for safe use can be engineered, skilled trade or professional users often have to rely on general ventilation or personal protective equipment as conventional engineering controls are often less effective or impractical. Notwithstanding this, priority should always be placed on the use of engineering controls over reliance of personal protective equipment.
Since methacrylate monomers are volatile organic compounds, there is a potential for exposure to both vapors and the liquid when handling products containing liquid monomer.
Inhalation Of Methacrylate Vapors
Methacrylate monomers have a characteristic odor and are irritating to the respiratory system. In addition, the acid is corrosive to the respiratory system. If there is insufficient natural ventilation to ensure compliance with the threshold limit value (TLV) then forced ventilation, or failing that, respiratory protection should be worn.
Contact With Liquid Methacrylate Monomers
It is recognized that Methacrylic acid is corrosive and the esters are weak skin sensitizers (contact allergens). Because of this MPA recommends that skin contact with liquid monomer is always avoided — wear protective gloves. See MPA's Position regarding the use of methacrylates in nail extensions and MPA's statement regarding gel nails.
As liquid monomers are typically formulated with other chemical substances in end-use products, users should always read the information contained within the SDS provided by the supplier of the end-product as it should contain important advice on how to use and dispose of the product safely.
Further information that may be helpful is contained in Methacrylate Monomers: Safe Use of Gloves, but this should be regarded as subordinate to any advice provided by the end-product manufacturer.
