Underwriters Laboratories Inc. (UL) provides approvals for modules, circuits and protective elements. If a device is approved it is called "UL recognized" and listed within a defined UL file. Another possibility is that materials are listed and classified by UL. These materials can be found again listed in certain UL files, where you can see for example the classification of flammability etc. Single diodes or transistors cannot be approved by UL, while bridge rectifiers - as so called "Graetz" circuit - can be UL recognized.

Most of the Diotec bridge rectifiers are UL recognized under
QQIJ2 (COMPONENT - POWER SUPPLIES, SPECIALTY).
They are listed in the File No. E175067 (PDF).

Some of the bridge rectifiers are additionaly UL recognized under
QQQX2 (Electrically Isolated Semiconductor Devices - Component).
They are listed in the File No. E313324 (PDF).

Diotec products that are not UL recognized are produced with materials that are UL listed and classified. We use molding and casting compounds having for such materials the most severe flammability classification UL94V-0:

For components with molding compound MG21F-02 (standard) see File No. E255557 (PDF)

For components with molding compound EME-120G (halogen free) see File No. E59481 (PDF)

For components with casting compound - Araldit CW 1195 BD / Härter HW 1196 - see File No. E72789 (PDF).