What Does UL Classified Mean?

By: Tamara Middleton, Sales Representative – Architectural Products


UL, Underwriters Laboratories, is an American consulting company that provides certification on the safety and environmental claims of a product.  In order to be classified under UL a product must meet specific standards.  These standards are determined by risks such as fire or shock, performance under certain conditions, regulatory codes, and other standards set by UL.  In order for a product to be labeled with a UL Classified mark it must meet the standards determined specifically for the product.

For EPS, Expanded Polystyrene, the standards include surface burning characteristics, density, dimensional tolerance, flexural strength, thickness, trueness, and squareness to name a few.  EPS manufacturers must test regularly for these standards.  Every batch produced must be tested daily for its density, flexural strength, thickness, and trueness.  A batch is a number of pounds of bead (raw material) molded at one time of one density from one lot# from an approved bead manufacturer. Dimensional tolerance is tested one series per production run.  The testing is completed by the manufacturer with full reports maintained and audited by a UL representative.  A UL representative will also periodically audit the manufacturers testing equipment, processes, and procedures.

All products manufactured for ASTM D6817 must also meet a compressive resistance standard determined by its density.  Compressive resistance testing is completed by an independent lab, using samples collected by the manufacturer.  Samples for each lot, density and day must be collected.

An EPS board with a UL classified mark has met all standards required by either ASTM C578 for insulation, ASTM D6817 for geofoam and ASTM E2430 for WSG.

ACH Foam Technologies Foam-Control® expanded polystyrene (EPS) insulation and EPS geofoam, along with Foam-Control® PLUS+® architectural rigid foam insulation, are recognized by UL.

All-Spec’s Official Blog, ‘What is UL certification’ by Andy, September 27, 2011
Cabling Install, ‘UL’s Listed, Classified and Verified Marks explained’ August 1, 2012
GAPS Guidelines, ‘Definitions of “listed,” Classified,” “Recogonized,” Approved,” “Acceptable”
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One Response to What Does UL Classified Mean?

  1. ampauthority says:

    Thanks for clearly defining what UL Classified means. There seems to be general confusion about the designation between UL Listed and UL Classified. We took out best shot here but would like to know your thoughts!


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