International Standard Procedure for the Extraction of Metal Compounds Having Soluble Threshold Limit Values

The lack of guidance on sample treatment procedures for the measurement of soluble metal compounds in workplace air samples has been problematic for years. It is the intention of the present article to address this important issue by alerting the occupational and environmental health community of the existence of a newly promulgated “soluble” metals procedure, which has been published recently in an International Standard. The subject matter of this article may not appear to deal directly with “instrument performance criteria”; however, sample preparation methods for soluble metal compounds are designbased, and do indeed have a bearing on the subsequent instrumental analysis. Several years ago, the issue of metals and solubility, as it pertains to theAmerican Conference of Governmental Industrial Hygienists’ (ACGIH°R ) Threshold Limit Values (TLVs°R ), was discussed extensively by Fairfax and Blotzer.1 The matter is revisited here in view of the recent Ž nal approval of an International Standard, developed by the International Organization for Standardization (ISO), which describes methods for extracting metals and metalloids from workplace air samples for their subsequent determination.2 One of the pro-