The proper fluid pressure at the spray tip is impacted by many variables including, but not limited to: equipment design, resin or gel coat properties, operating conditions and equipment setup. It is important to remember that the objective of NARA is to set up the spray gun to operate at the lowest effective pressure. Training your operator to follow the equipment manufacturer’s directions is the best way to meet this Composites MACT requirement.

The best practices of controlled spray and NARA were developed by ACMA to meet regulatory requirements. The benefits of these practices have been substantiated in stack tests and employee monitoring for styrene exposure. These best practices have the additional benefit of being lean and green.

The guest columnist for this issue’s “Best Practices” column is Mike Zais, Manager, Manufacturing Process Improvement for Xerxes Corporation – a ZCL company. Mike is also Chairman of the ACMA committee that maintains the Unified Emission Factors (UEF) for open molding. Email comments to