5.1 Hexavalent chromium is anthropogenic from a number of commercial and industrial sources. It readily penetrates biological membranes and has been identified as a carcinogen and industrial toxin. Hexavalent chromium is a known inhalation irritant and is associated with respiratory cancer (5).

5.2 Ambient atmospheric concentrations of hexavalent chromium are well below the detection limits of previous analytical methods utilized for the determination of hexavalent chromium (2).

5.3 Ambient atmospheric concentrations of hexavalent chromium provide a means of evaluating exposures in a manner that can be related to health-based risk levels. The data for samples collected in situ provide an improved basis for health assessments of potential exposures (5).

5.4 This test method provides step-by-step instructions for the sampling and analysis of total suspended ambient air particulates for hexavalent chromium.

5.5 This test method assumes that field and laboratory personnel are familiar with low volume ambient air sampling and hexavalent chromium analysis by ion chromatography with post-column derivatization. This method should not be performed for regulatory or compliance purposes until the field and laboratory personnel have demonstrated the ability to collect and analyze samples in such a manner as to pass the quality control requirements found in Section 13.

1.1 This test method specifies a procedure for the sampling and analysis of airborne particulate matter for hexavalent chromium in ambient air samples.

1.2 This method is applicable to the determination of masses of 0.40 to 20.0 ng of hexavalent chromium per sample without dilution. Detection limits vary by instrumentation. Some laboratories may be able to achieve lower detection limits. The lower limit of applicability for this method was determined in a 2019 multi-laboratory detection limit study (1).2

1.3 This method is applicable to hexavalent chromium measurement in the atmosphere from 0.019 to 0.926 ng/m³ assuming a 21.6 m³ sample volume. The lower range may be decreased with longer sampling times. The upper range can be increased using appropriate dilutions.

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 of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.6 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.