What is "Non-Atomized?"

Regarding non-atomized application devices, there are three different "regulations" that apply:

1. The ANSI/ACMA Unified Emission Factor (UEF) Table does not have any operational or certification requirements for non-atomized resin application. Most open molders use the UEF to estimate emissions for reports submitted to local and state regulators and to EPA.

2. According to the Indiana Dept. of Environmental Management "styrene rule" (326 IAC 20-25) requirement for non-atomized resin application, sources using non-atomized application equipment must comply with the following definition:

(20) “Nonatomized application equipment” means the devices where resin or gel coat material does any of the following:

(A) Flows from the applicator, in a steady state in a observable coherent flow, without droplets, for a minimum distance of three (3) inches from the applicator orifices, such as flow coaters, flow choppers, and fluid impingement equipment.
(B) Is mechanically dispensed within or on to a paint roller applicator, such as pressure fed rollers.
(C) Is deposited on fiber reinforcement moving through a resin or gel coat bath, such as resin impregnators.

California's South Coast Air Quality Management District has the same requirements for non-atomized resin application as IDEM.

3. Under the US EPA NESHAP (MACT rule) for composite manufacturing, the following definition applies:

Nonatomized mechanical application means the use of application tools other than brushes to apply resin and gel coat where the application tool has documentation provided by its manufacturer or user that this design of the application tool has been organic HAP emissions tested, and the test results showed that use of this application tool results in organic HAP emissions that are no greater than the organic HAP emissions predicted by the applicable nonatomized application equation(s) in Table 1 to this subpart. In addition, the device must be operated according to the manufacturer’s directions, including instructions to prevent the operation of the device at excessive spray pressures. Examples of nonatomized application include flow coaters, pressure fed rollers, and fluid impingement spray guns. (Emphasis added.)

So, for MACT, you do need documentation from the supplier showing both that the gun has been tested and that the test results show that the gun complies with the emission factors in Table 1 of the MACT rule. You also need operating instructions from the supplier, and the instructions need to include procedures that limit spray pressures.