Levels of performance characteristics required for a particular end-use product application shall be in accordance with the requirements of the end-use product standard.

In addition, some materials have been subjected to Fire Tests in accordance with Underwriters Laboratories Inc. Standard Test Method for Surface Burning Characteristics of Building Materials, UL723 which provides data concerning (1) flame spread, (2) fuel contributed, and (3) smoke developed. For the classification of building materials, see "Building Materials Directory".

Thermal Aging Program -The materials covered by this program have, in many cases, been investigated with respect to retention of certain critical properties (e.g. dielectric, tensile, impact, and the like) as part of a long-time thermal-aging program conducted in accordance with Underwriters Laboratories Inc. Standard for Polymeric Materials-Long Term Property Evaluations, UL746B. The end-of-life of a material at each test temperature in this program has been assumed to be the time when the value of the critical property had decreased to 50 percent of its original (as received) value. If a material has been investigated under the thermal aging program, the Relative Temperature Index (RTI), in degrees C shown is based on a comparison with a material which has acceptable service experience and correlates numerically with the temperatures above which the material is likely to degrade prematurely. If a material has not been investigated under the thermal aging program, the temperature index shown is based on the generic class of the material. A tabulation of the temperature indices according to generic material class is included in UL746B and is based on past field-test performance and chemical structure.

More than one RTI may be appropriate for a given material depending on the property requirements for a given application. In certain cases, higher temperatures are permitted if so specified by the end-use product standard.

Relative Temperature Index (RTI) - Maximum service temperature for a material, where a class of critical property will not be unacceptably compromised through chemical thermal degradation, over the reasonable life of an electrical product, relative to a reference material having a confirmed, acceptable corresponding performance defined RTI.

RTI Elec - Electrical RTI, associated with critical electrical insulating properties.

RTI Mech Imp - Mechanical Impact RTI, associated with critical impact resistance, resilience and flexibility properties.

RTI Mech Str - Mechanical Strength (Mechanical without Impact) RTI, associated with critical mechanical strength where impact resistance, resilience and flexibility are not essential.

Electrical Properties - Performance may be evaluated with respect to electrical track resistance, ability to resist ignition from electrical sources, and other electrical properties. Tests were performed using 60 Hertz unless otherwise specified.

Performance Level Categories-In order to avoid an excessive level of implied precision and bias, material performances for several tests are recorded as Performance Level Categories (PLC), based on the mean test results (rather than recording the exact numerical results), as indicated in the table following the test description.

Hot-wire Ignition (HWI) - Performance is expressed as the mean number of seconds needed to either ignite standard specimens or to burn through the specimens without ignition. The specimens are wrapped with resistance wire that dissipates a specified level of electrical energy.

High Amp Arc Ignition (HAI) -Performance is expressed as the number of arc rupture exposures (standardized as to electrode type and shape and electric circuit) which are necessary to ignite a material when they are applied at a standard rate on the surface of the material.

High Voltage Arc Tracking Rate (HVTR) - is denoted as the rate, is mm/min, that a tracking path can be produced on the surface of the material under standardized test conditions. Note is made if ignition on the material takes place. The results of testing the nominal 3 mm thickness are considered representative of the material's performance in any thickness.

Arc Resistance (D495) - in accordance with ASTM-D495 is expressed as the number of seconds that a material resists the formation of a surface conducting path when subjected to an intermittently occurring arc of high voltage, low current characteristics. The results of testing the nominal 3 mm thickness are considered representative of the material's performance in any thickness.

Comparative Tracking Index (CTI) - is expressed as that voltage which causes tracking after 50 drops of 0.1 percent ammonium chloride solution have fallen on the material. The results of testing the nominal 3 mm thickness are considered representative of the material's performance in any thickness.

IEC Glow Wire Ignitability Temperature (GWIT) - in accordance with IEC 695-2-1/3, is expressed as the temperature (in degrees C), which is 25 C hotter than the maximum temperature of the tip of the glow-wire which does not cause ignition of the material during three subsequent tests.

IEC Glow Wire Flammability Temperature (GWFI) - in accordance with IEC 695-2-1/2, is expressed as the highest temperature (in degrees C) at which, during three subsequent tests, flaming or glowing of the test specimen extinguish within 30 seconds after removal of the glow-wire without ignition of the indicator by burning drips or particles.

IEC Ball Pressure Temperature (BP) - in accordance with IEC 695-10-2, is expressed as the temperature (in degrees C) where a 5mm diameter ball causes a 2mm diameter or less impression on the material surface.

The above characteristics and dielectric strength, volume resistivity and other electrical and mechanical properties may be determined by means of the applicable ASTM and/or UL specification in the Underwriters Laboratories Inc. Standard for Polymeric Materials-Short Term Property Evaluations, UL746A. In addition to minimum electrical and ignition test levels, materials which are used in applications involving support or contact with current-carrying parts are also required to display a minimum stability (heat distortion, moisture resistance, dimensional stability and mold stress) performance level, as described in the Underwriters Laboratories Inc. Standard for Polymeric Materials-Use in Electrical Equipment Evaluations, UL746C.

To determine compliance of a material for a specific application, the test values generated for that material should be compared with the minimum performance level established for that application as outlined in the product standard.

Molding and Fabricating Considerations - To be acceptable for use in end-use product applications, some materials must meet applicable requirements concerning the molding and fabricating of finished parts as described in Underwriters Laboratories Inc. Standard for Polymeric Materials – Fabricated Parts, UL746D.

Manufacturers who produce the following components: Filament Wound Tubing, Industrial Laminates, Vulcanized Fibre, and Materials for use in Fabricating Printed Wiring Boards (QMTS2), Coatings for use on Recognized Printed Wiring Boards (QMJU2), Metallized Parts (QMRX2), Supplier Components for use in the Fabrication of Metallized Parts (QMSS2), Electrical Insulation Systems (OBJY2), Adhesives (QOQW2), Flame Retardants and/or Color Concentrates (QMQS2), or Molded Release Lubricants (QMSX2) are not covered under the Component Plastics category. Requirements concerning these products are located in the respective product category information pages.

The following are considerations to be made in judging the use of these materials in an end-use product.

1. Material identification traceability for parts covered under the Fabricated Parts (QMMY2) category.

2. Identification for a device employing parts molded of these materials should specify the parts' wall thickness, color, material identification, and traceability.

3. Unless otherwise indicated, suitability for use when exposed to weathering, oils, soaps, chemicals, x-rays and the like, has not been determined.

4. Evaluation of parts for other than the properties investigated, in accordance with the applicable UL end-use product standard and/or requirements outlined in the Standard for Polymers Material - Use in Electrical Equipment Evaluation, UL746C. Additional Conditions of acceptability may be included in the individual Recognition Reports.

Generic Material Symbols - The following are the most common symbols that may be used on the individual Recognitions to represent the generic material type. The generic material symbols are based upon the terminology developed in the International Organization for Standardization publications covering "Plastics-Symbols" (ISO 1043) and "Rubbers and Latices" (ISO 1629).

Foamed Materials - Materials which have been foamed with the introduction of a chemical blowing agent or inert gas may have significantly different properties than the unfoamed or solid material form; therefore, ratings that are established for solid (unfoamed) material do not automatically apply to the foamed version of that same material.

Investigation of Materials Used For Structural Parts in Room Air Conditioners - Where the retention of physical properties for a material have been investigated for structural parts in specific applications, such as room air conditioners, they are so noted in the individual Recognitions and meet a minimum level beyond which consideration depends on the actual design and use of the part.

Materials For Use in Special Environments - Investigation of materials for specific end-use product applications where requirements exist for the retention of properties after exposure to certain critical operating and/or environmental conditions, may be indicated in the individual Recognitions.

Composite Materials - These materials consist of a sandwich type construction of a metal and a plastic and have been tested for flammability only to determine compliance with UL94. They may also contain an adhesive which serves to bond the individual components into a composite structure.

Abbreviations - The following abbreviations are used on the column headings for the individual Recognitions.

Products Recognized under the Component Program are identified by significant markings, consisting of the manufacturer's identification and catalog, model or other product designation, which correspond with the marking specified in the Laboratories' published records. Only those components which actually carry the ''Marking'' shown in the individual Recognition should be considered as being covered under the Component Program. The Listing Mark of Underwriters Laboratories Inc. is not authorized for use on, or in connection with, Recognized Components.