Fiberoptic Personal Exposure Monitor for Diisocyanates

Details

• Personal Author:
  Lis SA
• Description:
  Spray-on polyurethane coatings applied during auto body repair expose workers to potentially harmful levels of diisocyanates. Workers also commonly risk exposure to harmful vapors during the manufacture of molded polyurethane foam products. Diisocyanates have been identified as the major cause of occupational asthma. Diisocyanates are highly toxic, used worldwide, and manufactured on a very large scale for the production of polyurethane and related chemical products. Since most human exposure occurs as the chemical vapors are transported by air, an air sampling based method having high sensitivity is required. Current measurement methods fail to provide adequate sensing of all diisocyanate species simultaneously. This program aimed to develop a highly sensitive fiberoptic personal monitoring device, similar to a sampling badge, targeted for the simple and convenient measurement of diisocyanate airborne exposure. A chemically reactive coating applied to the fiber provides a direct integrated response to diisocyanate vapors during exposure. Real time electronic readout is provided by a compact, battery powered device that provides rapid, low cost, feedback to the user of unhealthy exposure levels that are recorded and reported via digital electronics. Humidity and temperature compensation is integrated into the device so as to make exposure measurement more accurate. An explicit program goal was to make the device size and cost suitable for consistent use during typical auto body repairs and factory operation. The primary tasks of the program were: 1) Reagent selection, synthesis, and optical properties. Review literature to identify optimal chemical species for investigation. Obtain or synthesize necessary chemicals. Measure basic optical and chemical properties. 2) Electronic readout development. Develop fiber sensor circuit design. Develop and construct compact fiber cartridge design. Develop and construct compact final readout sensor unit for laboratory testing. 3) Exposure measurements. Develop fiber coating procedure. Prepare diisocyanate sample solutions. Make first stage exposure measurements of coated fibers to Diisocyanates. 4) Quantification of measurements. Refine performance measurement methods by comparison against calibrated sensing techniques. The primary findings of the program are as follows. A) An inexpensive, compact, optical fiber cartridge design was developed which can be quickly and reproducibly assembled from commercially available materials. B) An inexpensive, compact, optical readout device based on common LEDs and photosensors was developed which provides a real time digital readout of the fiber cartridge with a precision of 1 part on 5000. The device is battery powered and readily interfaced to a common computer via a USB cable. Custom software with a graphic interface was developed for data acquisition, display and real time analysis. C) The necessary chemical sensing agents were purchased or synthesized and a reproducible low cost dip coating process was developed for fiber sensor preparation. Spectral properties of these agents were characterized and matched with commercially available LED properties for optimal sensor performance. D) The chemical sensing agents tested demonstrated the necessary sensitivity to airborne diisocyanates but only under elevated temperature conditions. Simultaneously, it was determined that the sensing agents are highly sensitive to temperature and humidity and these factors can be mistaken for diisocyanate exposure. This additional sensitivity to atmospheric conditions makes the reliable measurement of diisocyanate exposure difficult to the accuracy levels desired for assurance of worker health. E) Further development of chemical sensing agents is required. It was concluded that the selected chemical fiber coating did not have all of the properties necessary for reliable diisocyanate sensing in a workplace environment. The sensor cartridge developed and the readout electronics are low cost and potentially suitable for this and other chemical sensing applications. The optical performance achieved lays the groundwork for future low cost sensing devices. Further study is required to identify chemical coatings that provide the necessary response. [Description provided by NIOSH]
• Subjects:
  Air Pollutants, Occupational Environmental Monitoring Isocyanates Occupational Health Respiratory System Respiratory Tract Diseases Safety
• Keywords:
  Airborne Particles Air Monitoring Air Sampling Equipment Diisocyanates Equipment Design Equipment Testing Measurement Equipment Monitoring Systems Occupational Respiratory Disease Polyurethane Foams Sensors Spraying Operations Wearable Technologies

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• Series:
  Grant Final Reports
• Publisher:
  National Institute for Occupational Safety and Health
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Final Grant Report
• Place as Subject:
  Massachusetts ; OSHA Region 1
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  OEP - Office of Extramural Programs
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  1-35
• NIOSHTIC Number:
  nn:20053648
• NTIS Accession Number:
  PB2019-100319
• Citation:
  Atlanta, GA: U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, R43-OH-009178, 2008 May; :1-35
• Contact Point Address:
  Steven A. Lis Ph.D., LightLine Technologies, Inc., 254 Marked Tree Rd., Needham, MA 02492
• Email:
  stevenlis@comcast.net
• Federal Fiscal Year:
  2008
• Performing Organization:
  LightLine Technologies, Inc., Needham, Massachusetts
• Peer Reviewed:
  False
• Start Date:
  20070801
• Source Full Name:
  National Institute for Occupational Safety and Health
• End Date:
  20080228
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:9dd1461967b4e2f071800c636f546796b23288ddc1db4715fce2832f61bb2671036f104d127de410f86b93622a3a0d013e3807bd3b1dbef791d1ae28f7cb258b
• Download URL:
  https://stacks.cdc.gov/view/cdc/218775/cdc_218775_DS1.pdf
• File Type:
  [PDF - 434.54 KB ]