Industrial Hygiene Monitoring Using the SIBS Heavy Metal Detector

Description

PSI's spark-induced breakdown spectroscopy (SIBS) technique has proven to be a fast, sensitive monitor for airborne heavy metals in industrial hygiene applications. The technology has been fully developed and field tested for lead and chromium. Upgrades are currently in progress for other RCRA metals (Cd, Hg, As, and Be).

Schematic of PSI SIBS Monitor

Occupational exposure to airborne heavy metals remains a significant concern, with OSHA estimating that nearly one million U.S. workers are exposed to lead alone. The PSI SIBS Heavy Metal Detector, shown schematically in the figure above, will help protect workers from metal exposure and reduce employer liability.

Industries that would benefit from the PSI monitor are:

• Construction (especially lead paint abatement projects)
• Hard chromium and other electroplating
• Primary and secondary lead production

Uses and Applications

• Indoor firing ranges
• Manufacturers of brass, copper, bronze and other nonferrous metals
• Decontamination and decommissioning activities at DOE hazardous waste sites
• Automobile radiator repair shops
• Electronics

Immediate Benefits

• Real time measurement
• Source mapping and contaminant migration
• Verification of clean and safe areas and conditions requiring PPE
• Integration with source mitigation and engineering controls

Additional Benefits After NIOSH Approval

• Record of actual exposure, reducing employer liability
• Accurate determination of concentrations exceeding action levels and PELs
• PSI SIBS Industrial Hygiene Monitor Specifications
• Pb, Cr detection limit - 8 ppbw (10 µg/m³)
• Dynamic range - >10³
• Spark frequency - 1 Hz typical
• Response time - adjustable from 1 second
• Sampling flow rate - 1.3 cfm
• Interferences - None encountered in laboratory or field testing to date
• Power - One 10 amp, 120 V line

Field Test Results

The PSI SIBS monitor has been successfully field tested in three different applications. The first was as a continuous emissions monitor (CEM) for lead and chromium in stack gases at a joint EPA/DoE field test at Research Triangle Park in September 1997. Industrial hygiene monitoring tests have been performed for lead at a firing range and for chromium at a hard chrome plating facility. Sample data from these applications are shown below.

Lead Firing Range Data

Total Chromium Data

The lead data were acquired in the ventilation airspace immediately before the HEPA filters of a state-of-the-art indoor firing range. The results show rapid response to airborne lead created by turbulence from the ventilation system initiation and from the various periods of active and sporadic firing. Finally, the lead created from a single shooter could be observed at the end of the test.

The PSI SIBS instrument responds to chromium containing individual particles and groups of particulate that drift upwards from the bath surface. This directly measures the fugitive chromium emissions from hard chrome plating baths. In a recent field test, the PSI SIBS data correlated well with distance above the bath surface, ventilation rate, and OSHA-approved sampling methods.

Product Development and Test Services

The SIBS Heavy Metal Detector is currently available as part of testing services offered by PSI. A NIOSH-approved commercial product will be available in 1999.

David M. Sonnenfroh Physical Sciences Inc. 20 New England Business Center Andover, MA 01810-1077 Telephone: (978) 689-0003 Fax: (978) 689-3232 sonnenfroh@psicorp.com