Technical Bulletin No. 0056: Evaluation of the Use of Humans in Measuring the Effectiveness of Odor Control Technology at the Source (AQTB)

The attached Technical Bulletin summarizes the results of a study conducted jointly by NCASI's West Coast Regional staff and Washington State University's Air Pollution Research Section. It sought to explore the present level of capability for organized use of human observers to measure the effectiveness of kraft mill odor control technology at the source through quantitative judgments concerning odor emission levels and qualitative observations concerning objectionability. The investigation produced recommendations for a number of improvements in observer panel selection techniques including criteria for preliminary screening out of unqualified observers prior to sensory screening of panel participants, sensory screening procedures, and possible assembly of a trained observer panel to serve as a reference standard for panels selected by less rigorous methods. A number of recommendations dealt with operating procedures for odor panel laboratories designed for this purpose covering subject isolation, source levels, transmittal of instructions, randomizing of odor order of presentation of odorous and control gaseous samples and parallel chemical analyses. It is hoped that review of these findings will further familiarize member company personnel with both the limitation to, and practical possibilities provided by, use of human observer panels for this purpose.