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Showing posts with label microscope analysis. Show all posts
Showing posts with label microscope analysis. Show all posts

Friday, March 14, 2008

Asbestos Discovered In Current Building Materials


Based on testing done by the Asbestos Disease Awareness Organizations (ADAO) and announced at a press conference on November 28, 2007 it appears there may be a concern that new building materials may contain asbestos. The ADAO conducted asbestos testing on over 250 different household products utilizing Polarized Light Microscopy (PLM) and Transmission Electron Microscopy (TEM) analysis in accordance with the Environmental Protection Agency's test method 600/R-93/116. The link above gives you the detail of the methodology and results of the testing that included positive results for 5 products including Planet Toys "CSI Fingerprint Examination Kit", DAP "33" window glazing and "Crack Shot" spackling paste, Gardner Leak Stopper roof patch (which listed asbestos as an ingredient on the label), and Scotch High Performance Duct Tape.

Of the 5 products found to contain asbestos, 3 products are materials that are considered building materials. The window glazing, the spackling paste, and the roof patch are all materials that an asbestos inspector would sample to determine if these materials contained asbestos in a building built before 1980, but would ignore in a building built after 1980. The results from the ADAO testing found the window glazing contained 2.73% chrysotile and tremolite asbestos, the spackling paste contained 1.05% tremolite, anthophyllite, and chrysotile asbestos and the roof patch contained 15% chrysotile asbestos. All of these materials would be considered asbestos containing materials for an asbestos inspector, if they were sampled. Again, based on the typical opinion of the industry we wouldn't sample these materials after 1980. In fact, New York State uses a cut-off date of 1974.

This new information from the ADAO, obviously calls into question New York State's cut off date of 1974. If the above products still contain asbestos today, it probably means these products had asbestos in them between today and 1974 or 1980. As an Asbestos Inspector this information calls into question our assumption regarding the asbestos content of building materials in buildings after 1974. Since asbestos has not been banned, and it can still be found in building materials we are presently installing, this means we can no longer use the 1974 or 1980 date to determine whether building materials do or do not contain asbestos. This is one of the many reasons why ADAO has been lobbying for a complete ban on the manufacturer and the use of asbestos.

It is important to remember that though the New York State Industrial Code Rule 56 asbestos regulation does not regulate the assumption of asbestos in building materials after 1974, it does regulate the remediation of asbestos no matter the date of the building.

Monday, April 16, 2007

VAT Article from our 2007 Spring Newsletter.


A study published in the 2003 issue of “Applied Occupational and Environmental Hygiene” magazine titled “Asbestos Release During Removal of Resilient Floor Covering Materials” by Marion Glenn Williams, Jr. and Robert N. Crossman, Jr. of the University of Texas Health Center indicated that worker's exposure to asbestos during vinyl asbestos floor tile (VAT) removal may be under reported. Because we work in New York (NYS), we are very familiar with the limitations of polarized light microscopy (PLM) analysis on VATs or for that matter on any nonfriable organically bound (NOB) material. Under NYS Environmental Laboratory Accreditation Program (ELAP) requirements materials that are considered NOBs must go through a multiple step process for analysis. This process ends with analysis by Transmission Electron Microscopy (TEM) for samples that are negative for asbestos. This method is required for VATs because the type of asbestos typically used was Grade 7 asbestos known as Shorts & Floats. Grade 7 asbestos is no longer sold and was the cheapest asbestos material sold. The dimensions of this grade of asbestos was ultra-fine. With fiber dimensions approaching the less than 5 micron range. This study was done to determine if there was fiber release at the less than 5 micron level that was not being analyzed by the Phase Contrast Microscopy (PCM). PCM is used for air sample analysis and only analyzes greater than 5 micron fibers with a 3:1 or greater length to width ratio. The study found the following issues:

  • When removing a non-asbestos sheet vinyl flooring with an asbestos felt backing the PCM method only reported 5-7% of the fibers counted by the TEM method.

  • When removing an asbestos containing 12x12 VAT with asbestos containing mastic the PCM method only reported 2-2.5% of the fibers counted by TEM.

  • When removing an asbestos 9x9 VAT with an asbestos mastic the PCM method reported 0-2.5% of the fibers counted by TEM.

  • When removing mastic using a mastic remover (TEM levels were between 1.319-1.749 structures/cubic centimeter (s/cc)) versus amended water (TEM levels were between 0.094-0.184 s/cc).

This study shows that air sample results are significantly underreported using the PCM method of analysis. When performing VAT removals asbestos air monitors and project monitors should be using TEM analysis for clearance (at the very least) and they should be running a few TEM samples during the actual removal of the VATs. These would give us a better understanding of what is happening during VAT removals and ensure that the asbestos abatement was thoroughly completed.

That Time of Year! Conferences, Posting Requirements, and OSHA Violations Increased!

It's that time of year again. We're between conferences.  February 15-16, 2024 was the Professional Abatement Contractors of New Yor...