5.1 This test method is designed to obtain styrene purity on the basis of impurities normally present in styrene and may be used for final product inspections and process control.

5.2 This test method will detect the impurities shown in Table 1, non-aromatic hydrocarbons containing ten carbons or less, and others where specific impurity standards are available. Absolute purity cannot be determined if unknown impurities are present.

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.

Ethylbenzene

o-xylene

m-xylene

p-xylene

Isopropylbenzene

n-propylbenzene

m-ethyltoluene

p-ethyltoluene

α-methylstyrene

m-vinyltoluene

p-vinyltoluene

Phenylacetylene

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 In determining the conformance of the test results using this method to applicable specifications, results shall be rounded off in accordance with the rounding-off method of Practice E29.

1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.5 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.