All electrically controlled devices or systems in the USA must be approved. Conformity with national safety regulations is demonstrated by a mark of conformity from a qualified, recognised testing laboratory.
The most widely recognised testing laboratory is UL (Underwriters Laboratories). UL conducts tests according to UL standards, which incorporate national standards as an essential component.
UL standards for the certification of Festo products:
- Electrical and mechanical hazards in the case of electrical products
- Housing materials and insulation materials in the case of fire-protection tests
- Valves: bursting pressure test at 5x the rated pressure
- Inspection of production facilities by UL
Further information about the various UL marks which appear on Festo products can be found on the tabs below.
| Mark | Definition |
|---|---|
 | Ready-to-install devices certified in accordance with US and Canadian regulations, e.g. limit switches with cables and plug. |
 | Ready-to-install devices certified in accordance with Canadian regulations, e.g. limit switches with cables and plug. |
 | Ready-to-install devices certified in accordance with US regulations, e.g. limit switches with cables and plug. |
 | Devices intended for integration inside larger products or systems and certified in accordance with US regulations, e.g. valve terminals. |
 | Devices intended for integration inside larger products or systems and certified in accordance with Canadian regulations, e.g. valve terminals. |
 | Devices intended for integration inside larger products or systems and certified in accordance with US and Canadian regulations, e.g. valve terminals. |