Polyurethane, polyurea and polyurea hybrid spray-on truck bed lining (TBL) products have been in use for more than fifteen years. These tough, elastomeric, plural-component products protect pickup truck/cargo van beds and other surfaces by creating a slip-resistant coating. However, the application process presents some potential health hazards to the applicator because most TBLs contain diphenyl methane diisocyanate (MDI). MDI, like diisocyanates in general, can cause irritation to the eyes, nose, throat, lungs and skin. In addition, skin sensitization (allergic dermatitis) and respiratory sensitization (asthma) can be caused or made worse by overexposure to MDI. The reader is urged to read the Material Safety Data Sheet specific to the product in use for a more complete discussion of potential health effects.