This practice covers a system of general classification or nomenclature for rubber and rubber latices. Rubbers in both dry and latex form shall be coded from the chemical composition of the polymer chain using the following classes: M, N, O, R, Q, T, U, and Z. The M shall be classified as follows: ACM, AEM, ANM, BIMSM, CM, CFM, CSM, EOM, EPDM, EPM, EVM, FEPM, FFKM, FKM, Type 1, Type 2, Type 3, Type 4, Type 5, and IM. The O class shall be classified as follows: CO, ECO, GECO, and GPO. The R class shall be classified as follows: ABR, BIIR, BR, CIIR, CR,ENR, ENRG, HNBR, IIR, IR, NBR, NIR, NR, NRG, PBR, PSBR, SBR, SIR, XBR, XSBR, and XNBR, where the parenthetical letter S or E shall be used to indicate whether the rubber or latex was prepared by solution or emulsion polymerization and the prefix X shall be used if the rubber have substitute carboxylic acid groups. The Q shall be classified as follows: FMQ, FVMQ, PMQ, PVMQ, MQ, and VMQ. The U class shall be classified as AFMU, AU, And EU. The T class shall be classified as OT and EOT. The Z class shall be classified as FZ and PZ. Mixtures of rubbers are identified by using the class designations for the types of rubbers in the mixture, with the major component listed first if the composition is known and in alphabetical order if the rubbers are present in equal amounts.

1.1 This practice covers a system of general classification for the basic rubbers both in dry and latex forms determined from the chemical composition of the polymer chain.

1.2 The purpose of this practice is to provide a standardization of terms for use in industry, commerce, and government and is not intended to conflict with but rather to act as a supplement to existing trade names and trademarks.

1.3 In technical papers or presentations the name of the polymer should be used if possible. The symbols can follow the chemical name for use in later references.

Note 1: For terms related to thermoplastic elastomers, see Practice D5538.