Technical report on airborne endotoxin measurement validation studies.

Details

• Personal Author:
  Milton DK
• Description:
  The optimal and standardized methods for measuring endotoxin have not been established. Several publications have suggested that one or another combination of collection and extraction methods are superior. However, the results of these studies give mostly contradictory signals. The discrepancy between studies and the need for better understanding and standardization of the methods is nowhere clearer than in the area of indoor air quality where different laboratories have reported more than 100 fold differences in the "normal" levels of airborne endotoxin. In this project, we developed an aerosol chamber capable of achieving mass balance for both gravimetric measurements, and to a lesser extent, endotoxin and LPS measurements. By using gravimetric measurements and LPS measurements, we established two internal standards for comparison of the levels of endotoxin activity recovered from the aerosol chamber. We found that changes in the extraction media used for the endotoxin samples caused large shifts in the apparent potency of the starting materials. These shifts would have suggested that a nonionic detergent (Tween-20) was a superior means of extracting endotoxin from filters. However, by comparison with the internal standards, and by computing yields based on a mass balance, we were able to show that this appearance was merely an artifact of Tween-20's interference with the Limulus assay. The highest valid yields of both endotoxin activity and LPS were achieved by collection of aerosol on capillary-pore polycarbonate filters and extraction in a phosphate triethylamine buffer.
• Subjects:
  Accidents, Occupational Dust Manufacturing And Industrial Facilities Occupational Health Personal Protective Equipment Respiratory Protective Devices Respiratory System Safety
• Keywords:
  Analytical Methods Bioassays Dust Analysis Endotoxins Microorganisms Sample Preparation Solvent Extraction
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Other
• Place as Subject:
  Massachusetts ; OSHA Region 1
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  1-16
• NIOSHTIC Number:
  nn:20024791
• Citation:
  NIOSH 1998 Jul; :1-16
• Contact Point Address:
  Environmental Health Harvard School of Public Hlth 665 Huntington Ave Boston, MA 02115
• Federal Fiscal Year:
  1998
• NORA Priority Area:
  Pulmonary System Disorders
• Performing Organization:
  Harvard University, Boston, Massachusetts
• Peer Reviewed:
  False
• Start Date:
  19940930
• Source Full Name:
  National Institute for Occupational Safety and Health
• End Date:
  19970929
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:9c0b1b4710a9ac43751cd9549ab763cf646b6bfd58950d65492c88cfb2953ebffd7513ffe1a1fbfa34ae5e2a809c4cfae4dfe6b2e93a786330569ffb0b3ea58f
• Download URL:
  https://stacks.cdc.gov/view/cdc/181206/cdc_181206_DS1.pdf
• File Type:
  [PDF - 6.29 MB ]