UL Standards
Underwriters Laboratories (UL) is one of the leading developers of product safety standards which manufacturers use in designing and producing safe products. All of UL's Standards for Safety are compatible with the U.S. National Electric Code and other nationally recognized installation, building and safety codes. Over 800 Standards for Safety have been published by UL.

UL 583, UL 1203 and UL 1604 are the Standards for Safety that contain the technical requirements that EX trucks must meet to become eligible to be labeled as Explosion Proof. It is not sufficient to say that products are built to these UL standards. Only products tested by UL that meet these standards are eligible to bear the UL Mark.

All UL labeled Gregory EX Trucks have been tested and Classified by UL and meet or exceed UL 583, UL 1203 and UL 1604 Standards for Safety. In addition, as a UL Classified Type EX truck, Gregory EX Trucks have all utilized electrical components separately tested and approved prior to testing the entire forklift electrical system for EX integrity.

UL 583 - Electric-Battery-Powered Industrial Trucks
View the UL 583 summary from the UL Website
A Type EX truck must meet the fire and shock hazard requirements of UL 583. UL performs a series of tests for UL 583 Classification Testing which include: abnormal operation test, electrical component temperatures test, brake test, dielectric voltage withstand test, arc-rupture tests on motor controllers and switching contacts in all circuits, burnout test, and solid-state circuitry component malfunction analysis.
  
UL 1203 - Explosive-Proof and Dust-Ignition-Proof Electrical Equipment for Use in Hazardous (Classified) Locations
View the UL 1203 summary from the UL Website
A Type EX truck used in Division 1 Hazardous Locations must meet UL 1203 requirements. Explosion Proof enclosures for Class I, Division 1 trucks are subjected by UL to explosion and hydrostatic pressure withstand test during UL 1203 Classification Testing. UL also performs dust penetration and dust blanket temperature tests for dust-ignition-proof enclosures for Class II, Division 1 trucks.

UL 1604 - Electric Equipment for Use in Class I and Class II,
Division 2, and Class III Hazardous (Classified) Locations
View the UL 1604 summary from the UL Website
A Type EX truck used in Class I, Division 2 Hazardous Locations must meet UL 1604 requirements. During UL 1604 Classification Testing, UL conducts a spark ignition test, nonincendive components tests, dust-tight-enclosure tests and sealed device tests.