Standard Active Last Updated: May 19, 2021
ASTM D3841-21

Standard Specification for Glass-Fiber-Reinforced Polyester Plastic Panels


This specification covers glass-fiber reinforced polyester plastic panels intended for use in construction. Light transmitting panels covered by this specification are divided into two types, based on relative response to a laboratory flammability test: Type CC1 for limited flammability and Type CC2 for general purpose. These types may be further subdivided by grades based on relative response to weathering tests: Grade 1 for weather resistance and Grade 2 for general purpose. The polyester resin used in the panels shall be a thermosetting styrenated and acrylated polyester resin composed of polymeric esters in which the recurring ester groups are an integral part of the main polymer chain. The resin shall be reinforced with glass fibers. The polyester resin may contain additives for various purposes. The materials shall be tested for water absorption, tensile strength, linear thermal expansion, and flexural strength.


1.1 This specification covers the classification, materials of construction, workmanship, minimum physical requirements, and methods of testing glass-fiber reinforced polyester plastic panels intended for use in construction. Panels for specialized or unique applications have the potential to require values significantly above or below those stated in this specification. Recommended practices for certain specific applications are included as Appendix X1. This specification is not intended to restrict or limit technological changes affecting performance when those changes are agreed upon between the purchaser and the seller.

1.2 Supplementary information on chemical resistance, resistance to heat, and installation practices are provided in Appendix X1.

1.3 The classification of these plastic panels into types based on relative response to a laboratory test shall not be considered a fire hazard classification.

1.4 The values stated in inch-pound units are to be regarded as the standard. The values given in parentheses are for information only.

1.5 The text of this standard references notes and footnotes which provide explanatory material. These notes and footnotes (excluding those in Tables and Figures) shall not be considered as requirements of this standard.

1.6 Fire properties are determined by using laboratory flammability tests (Test Methods D635, D1929, and E84).

1.6.1 This standard is used to measure and describe the response of materials, products, or assemblies to heat and flame under controlled conditions, but does not by itself incorporate all factors required for fire hazard or fire risk assessment of the materials, products or assemblies under actual fire conditions.

1.6.2 Fire testing is inherently hazardous. Adequate safeguards for personnel and property shall be employed in conducting these tests.

1.7 The following precautionary caveat pertains only to the test method portion, Section 8 of this specification. This specification does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this specification to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

Note 1: There is no known ISO equivalent to this standard.

1.8 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

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Book of Standards Volume: 08.03
Developed by Subcommittee: D20.24
Pages: 6
DOI: 10.1520/D3841-21
ICS Code: 83.120