1.1 This test method covers the determination of the impurities typically found in styrene and uses those values to determine the purity of styrene by difference by gas chromatography. Typical impurities in commercial styrene are found in Table 1.

1.2 This test method is applicable to impurity concentrations in the range of 0.001 to 1.00 % and for styrene purities of 99 % or higher when using the internal standard procedure.

1.3 The following applies to all specified limits in this standard: for purposes of determining conformance with this standard, an observed value or a calculated value shall be rounded off "to the nearest unit" in the last right-hand digit used in expressing the specification limit, in accordance with the rounding-off method of Practice E 29.

1.4 This standard does not purport to address all the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. For a specific hazard statement, see Section 9.