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Change of Method Reference for Organic Vapors

Notice to Lab Customers

For years, Assay Technology has referenced a modified version of OSHA #7 (Organic Vapors) on our reports for most of the chemicals collected on charcoal media. (Badges:  546, 566, 521, and 525 for chemicals like benzene, IPA, and methylene chloride.) This method is very similar or the same as many of the other methods OSHA and NIOSH have validated many methods over the years. Essentially:

  • Collect the organic vapor on charcoal media.
  • Extract the chemicals of interest from the charcoal using carbon disulfide and perhaps a polar cosolvent.
  • Determine the amount of the chemicals of interest are present using a GC with an FID detector, which includes
    • Multi-level calibration
    • Reporting limit studies
    • DE studies
    • 2nd source calibration verification
    • etc.

Here are some examples:

NIOSH 1300  for ketones  https://www.cdc.gov/niosh/docs/2003-154/pdfs/1300.pdf

NIOSH 1401 for alcohols  https://www.cdc.gov/niosh/docs/2003-154/pdfs/1401.pdf

OSHA 12 for benzene  https://www.osha.gov/dts/sltc/methods/organic/org012/org012.html

OSHA 1001 for PCE and TCE https://www.osha.gov/dts/sltc/methods/mdt/mdt1001/1001.html

Rather than reference many methods, which are essentially the same, Assay Technology decided to simply refer to the generic OSHA Method #7.

Recently, OSHA decided to retire OSHA #7 and in response, the AIHA has required labs to reference an analytical method or methods that are not retired. Again for simplicity, Assay Technology has decided to reference one method instead of many. Recently, we changed our reports and documentation so they refer to our internal method for “Organic Vapors” instead of a Modified OSHA 7.

Referencing an internal method is absolutely allowed by the AIHA.  We have been referencing internal methods for nitrous oxide and mercury for some time now. Changing the method reference to our internal SOP in no way changes what we have been doing for years and complies with ISO 17025 policies.

Our internal method summary can be summarized as:

  • Collect the organic vapor on charcoal media inside a badge or tube.
  • Extract the chemicals of interest from the charcoal using one of the following solvent mixtures:
    • Carbon disulfide with benzyl alcohol (most common). This is our list A.
    • Carbon disulfide with 1-butanol. List B.
    • Carbon disulfide. List C.
  • Determine the amount of the chemicals of interest are present using a GC with an FID detector.

Our internal method has the following improvements over OSHA 7 and most similar methods listed on the OSHA and NIOSH site:

  • Internal Standard (2) Method.
  • GC injection is split into dual columns. So every result is automatically confirmed.
  • Use of modern capillary columns.

These modifications are important and improve the quality of our reports.

If you have any questions, please contact us.  See the Customer Support tab on the website.