Monitoring to Detect Episodic Releases of Toxic Gases
John Urmson - Telos Labs, Inc. , Paul Yakubek - Signetics Corp. , Larry Fluer - Fluer, Inc. (SSA Journal - February 1988 pp. 35 - 46 )
Presented is the public reaction and increased awareness to episodic releases of toxic materials into the community. Federal Government definitions of "toxic" and "highly toxic" in 1983 establish a basis for controls recognizing those levels of material hazard which are most likely to create adverse problems with personnel both in the manufacturer's plant site, and in the surrounding community. Controls surrounding these two degrees of toxicity, and the determination of presence of these materials in an accidental release is the focus. Changes to Article-80 of the Uniform Fire Code (a model code used throughout the 17 Western United States) have incorporated controls for containment and treatment of a worst case, hypothetical release of toxic material. Monitoring by continuous gas detection equipment is required in the work area and at the discharge point from the required exhaust or treatment system. The discharge limit equal to 1/2 IDLH (Immediately Dangerous to Life or Health) is addressed along with monitoring instrumentation and applications utilizing advanced technology that is currently available. Aritcle-80 definitions for continuous gas monitoring are examined along with some design features required for compliance monitors. Gas detection methods of mass spectroscopy and FT-IR (Fourier Transform Infra-red) spectroscopy are compared with more sophisticated systems using separation science in conjunction with "Intelligent detectors" such as GC/ mass spectroscopy or GC/ FT-IR. Selection of the proper detection method and instrumentation will meet not only the design criteria, but also the detection and monitoring strategies of early warning, preventive action controls, employee/community protection and notification requirements.