1. H2S Gas Meter/Detector

2. Introduction Air monitoring data is useful for: *Assessing the health risks to the public and response workers. *Selecting personal protective equipment. *Delineating areas where protection is needed. *Determining actual or potential effects on the environment. *Selecting actions to mitigate the hazards safely and effectively.

3. H2S Gas Meter/Detector To be useful air monitoring instruments must be: *Portable and rugged. *Easy to operate. *Easy to operate. *Inherently safe. *Inherently safe. *Able to generate reliable and useful results. *Able to generate reliable and useful results.

4. Toxic Atmosphere Monitors Toxic atmosphere monitoring is done to: *identify airborne concentrations that could pose a toxic risk to response workers and the public. *evaluate the need for and type of personal protective equipment. set up work zones or areas where contaminants are or are not present. set up work zones or areas where contaminants are or are not present.

5. H2S Gas Meter/Detector The response time, sensitivity, selectivity, accuracy and precision of an instrument are important in evaluating the reliability and usefulness of the data the instrument generates. The response time, sensitivity, selectivity, accuracy and precision of an instrument are important in evaluating the reliability and usefulness of the data the instrument generates.

6. Toxic Atmosphere Monitors H2S must be monitored via real-time instruments because H2S must be monitored via real-time instruments because  Highly toxic  Causes olfactory desensitization  Prevalence in confined spaces  Primary cause of death in confined spaces

7. H2S Gas Meter/Detector Limitations & Considerations Temperature Temperature Oxygen Levels Oxygen Levels Interfering Coumpounds Interfering Coumpounds  Organic Lead  Sulfur compounds  Silicone  Acid Gases

8. H2S Gas Meter/Detector There are several gas monitors which utilize electrochemical cells or metal oxide semi- conductors (MOS) for detecting specific chemicals. There are several gas monitors which utilize electrochemical cells or metal oxide semi- conductors (MOS) for detecting specific chemicals. The most common monitors are used to detect carbon monoxide or hydrogen sulfide but there are also monitors available for hydrogen cyanide, ammonia and chlorine. The most common monitors are used to detect carbon monoxide or hydrogen sulfide but there are also monitors available for hydrogen cyanide, ammonia and chlorine.

9. H2S Gas Meter/Detector Technology Technology  Electrochemical cells  Solid-state sensors

10. H2S Gas Meter/Detector Low power requirements Low power requirements  Continuous operation for up to four months  Can fit in shirt pocket

11. H2S Gas Meter/Detector Calibration is performed electonically or by sample gas Calibration is performed electonically or by sample gas Factory calibration is recommended annually Factory calibration is recommended annually Sensor life may be dependent on use Sensor life may be dependent on use

12. References Cited NIOSH Manual of Analytical Methods (NMAM®), 4th ed. DHHS (NIOSH) Publication 94-113 (August, 1994), Cassinelli, M.E. & O'Connor, P.F. (pfo1@cdc.gov), Eds. O'Connor, P.F. (pfo1@cdc.gov)O'Connor, P.F. (pfo1@cdc.gov)

13. Bibliography DiNardi Salvatore R. (1998) The Occupational Environment-Its Evaluation and Control, AIHA, Fairfax, Virginia DiNardi Salvatore R. (1998) The Occupational Environment-Its Evaluation and Control, AIHA, Fairfax, Virginia Goetsch David L. (1999) Occupational Safety and Health for Technologists, Engineers, and Managers, Prentice Hall, Upper Saddle River, New Jersey Goetsch David L. (1999) Occupational Safety and Health for Technologists, Engineers, and Managers, Prentice Hall, Upper Saddle River, New Jersey