End-of-Service Life Indicator (ESLI)

Details

• Personal Author:
  Clapsaddle BJ ; Galloway AD ; Gebhard SC ; Looker MJ ; Mundschau MV ; Srinivas G
• Description:
  Gas masks and respirators employing activated carbon, with or without additives, to remove a wide variety of air-borne toxic substances, have been in use for well over 100 years. In this Small Business Innovation Research Phase I project, the goal was to develop and test indicators that changed color as the protective carbon reached its end-of-service life, but with about 20% of its service life remaining in order for the user to evacuate the area and replace the cartridge with a fresh carbon air filter. Three types of colorimetric indicator were tested in Phase I and are under further development in Phase II. One indicator is for detection of organic compounds and changes color when exposed to a variety of toxic organic chemicals. This indicator was tested extensively against 400 parts per million by volume isopropyl alcohol (the upper permitted exposure level), in various level of relative humidity (5, 50 and 90% relative humidity), at room temperature (20 degrees C), as recommended by staff at the National Personal Protection Technology Laboratory. This indicator changes color as it oxidizes organic substances and works well with other easily-oxidized alcohols such as methanol and ethanol. It was also tested against the aromatic hydrocarbon, toluene, and worked well. In Phase II, many additional toxic organic compounds of interest in occupational health will be tested. A second indicator changes color upon exposure to acid gases and was tested against sulfur dioxide, also in 5, 50 and 90% relative humidity at 20 degrees C and worked well. Phase II will test this acid indicator against hydrogen chloride and other acid gases of concern to worker health. A third indicator is designed to change color upon exposure to basic gases and was tested in Phase I against ammonia, and worked well in 5, 50 and 90% relative humidity at 20 degrees C. Ammonia has been of growing concern for the estimated 700,000 workers in agriculture, who are increasingly exposed to toxic levels of ammonia released from concentrated animal feeding lots. Exposure to toxic levels of ammonia can lead to a variety of respiratory illness as well as to blindness. In Phase I, color changes were rigorously quantified by standardized procedures of the International Commission on Illumination. Additional tests were run for all three indicators at -10 degrees C and +40 degrees C (just above body temperature of +37 degrees C), and all performed well. A prototype respirator was designed, built and tested with the three types of colorimetric indicator, each placed next to a reference color band with fixed color for comparison. In Phase II, formulations of the colorimetric indicators are to be optimized to achieve extended shelf life of approximately three years and to minimize premature color changes due to storage, photodecomposition, and exposure to the carbon dioxide (an acid gas) of the atmosphere and other substances off-gassing from the activated carbons and respirator wall materials. [Description provided by NIOSH]
• Subjects:
  Air Pollutants, Occupational Environmental Monitoring Hazardous Substances Occupational Health Personal Protective Equipment Respiratory Protective Devices Safety
• Keywords:
  Acid Gases Air Monitoring Air Sampling Equipment Detectors Filters Monitoring Systems Oxidation Personal Protective Equipment PPE Respirators Toxic Gases Warning Signals

  More +
• Series:
  Grant Final Reports
• Publisher:
  National Institute for Occupational Safety and Health
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Final Grant Report
• Place as Subject:
  Colorado ; OSHA Region 8
• 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:20052916
• NTIS Accession Number:
  PB2019-100115
• 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-009341, 2011 Feb; :1-35
• Contact Point Address:
  Girish Srinivas, TDA Research, Inc., 4663 Table Mountain Drive Golden, Colorado, 80403-1626
• Email:
  gsrinivas@tda.com
• CAS Registry Number:
  Carbon (CAS RN 7440-44-0)
• Federal Fiscal Year:
  2011
• NORA Priority Area:
  Public Safety
• Performing Organization:
  TDA Research, Inc., Wheat Ridge, Colorado
• Peer Reviewed:
  False
• Start Date:
  20090901
• Source Full Name:
  National Institute for Occupational Safety and Health
• End Date:
  20100831
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:d7990e5e1b5c3847d4929a9ad17ccca9389d3f2de6838906b6e812a01545ffcb8d41f28cb5f1d6b288f7576b1b48ad38d8b0ff948ef877b09f3114480b998343
• Download URL:
  https://stacks.cdc.gov/view/cdc/218729/cdc_218729_DS1.pdf
• File Type:
  [PDF - 1.81 MB ]