General Health and Safety Precautions
Care must be taken whenever fabricating or thermoforming any thermoplastic, including Plexiglas® acrylic sheet. The heat of thermoforming, cutting, machining, finishing, annealing, or otherwise processing Plexiglas® acrylic sheet may result in the release of vapors or gases, including methyl methacrylate (MMA) monomer. Additionally, cementing Plexiglas® acrylic sheet introduces other vapors related to the formulation of the adhesives. However, thermoforming Plexiglas® acrylic sheet, in accordance with recommended techniques at recommended temperatures and with adequate ventilation, should not result in harmful concentrations of vapors or gases in the workplace.
Each of the segments in this manual contains a section on any special hazards or precautions related to the process and materials under discussion. Fabricators and other users of Plexiglas® acrylic sheet are advised to read all of these Health and Safety Precautions sections carefully, to become thoroughly familiar with the properties of these materials, and to take all actions recommended for the safe use and processing of the products. Material Safety Data Sheets should be available from the manufacturer for these purposes.
General Fabrication Considerations
Concentration Levels and Ventilation Standards
Most fabrication and forming techniques for Plexiglas® MC acrylic sheet are similar to those used for Plexiglas® G cell-cast acrylic sheet, although there are some slight differences, which are noted in the appropriate sections.
High concentrations of MMA vapors can cause eye and respiratory irritation, headache and nausea. The American Conference of Governmental Industrial Hygienists (ACGIH) Air Contaminant Standard for MMA places the maximum permissible exposure level at a time weighted average (TWA) of 50 ppm.
It is always good practice to provide local exhaust ventilation as close to the point of possible generation of vapors as practical. Suggestions for the design of exhaust ventilation systems are provided in Industrial Ventilation Manual of Recommended Practice (2004), published by the ACGIH, and American National Standards Institute Fundamentals Governing the Design and Operation of Local Exhaust Systems, ANSI/AHAZ9.2-2001.
In order to maximize the beneficial features of each of the sheet products, certain fabrication techniques may differ in working with Plexiglas® G acrylic sheet and Plexiglas® MC acrylic sheet. If questions arise after trying the suggested techniques, please contact the Altuglas International Polymer Technology Center at 800-217-3258 or one of the Sales Offices listed on the back of this manual.