GRINDING METAL WITH CARBORUNDUM.
`BLACK MAGIC DIAMOND WHEEL
`WORK PRACTICE STUDY
`Prepared by
`® | William E. Longo, Ph.D.
`Richard L. Hatfield
`May, 1999
`Materials Analytical Services, Inc.
`; Raleigh Office: Atlanta Office:
`616 Hutton Street * Suite 101 3945 Lakeheld Court
`Raleigh, NC 27606 Suwanec, Georgia 3(K24
`(919) 829-7041 » FAX (919) 829-5518 / (770) 866-3200 * FAX (770) 866-3259
`
`* FILED: NEW YORK COUNTY CLERK 01/29/2024 07:20 PM
`NYSCEF DOC. NO. 188
`
`INDEX NO. 190088/2021
`
`RECEIVED NYSCEF: 01/29/2024
`
`

`

`Work Practice Study of Asbestos Exposure while Grinding
`with a Carborundum Black Magic Diamond Wheel
`EXECUTIVE SUMMARY
`A Carborundum Black Magic grinding wheel was provided to MAS in order to perform a
`grinding work practice simulation. An analysis of the grinding wheel confirmed that the
`inner portion of wheel contained approximately 35% by volume of chrysotile asbestos.
`The grinding section of the wheel which contains the diamond material, was found to be
`negative for asbestos. The Carborundum Black Magic Diarnond wheel was placed on a
`Cincinnati #2 Tooling and Cutter Grinder and a tungsten carbide strip was used for
`grinding. A machinist with 18 years experience provided the expertise to run the
`grinding operation.
`Air samples taken during this work place simulation provided the following results:
`AVERAGE ANALYTICAL RESULTS FOR AIR SAMPLES
`Number
`of PCM TEM (all)
`Samples | fibers/cc | Structures/cc
`Background sampies 3 0.001 0.000
`-| Before Grinding Operation .
`3 0.047
`Area Samples During Grinding 0.000
`| Personnel Samples During Grinding 6 0.029 0.000
`As can be seen from these results, the fibers detected by PCM is well below any current
`or past OSHA standards. Furthermore, the TEM results show that the fibers detected
`by PCM were in fact, all non-asbestos in nature. In conclusion, these results show that
`when the asbestos containing Carborundum Black Magic Diamond wheel is used in the
`work place, asbestos fibers are not released into that environment.
`*
`
`FILED: NEW YORK COUNTY CLERK 01/29/2024 07:20 PM
`NYSCEF DOC. NO. 188
`
`INDEX NO. 190088/2021
`
`RECEIVED NYSCEF: 01/29/2024
`
`

`

`INDEX NO. 190088/2021
`
`RECEIVED NYSCEF: 01/29/2024
`
`FILED: NEW YORK COUNTY CLERK 01/29/2024 07:20 PM
`NYSCEF DOC. NO. 188
`
`Work Practice Study of Asbestos Exposure While
`Grinding with a Carborundum Black Magic Diamond Wheel
`This study was designed and conducted by Richard Hatfield, William Longo and Ben Adair
`Study Design and Methodology
`The study was performed in an isolation chamber constructed using typical asbestos
`abatement protocols. The size of the chamber is approximately 15’x 20’x 8’. The
`chamber is constructed with two. viewing windows for video taping purposes and has an
`air exchange rate of approximately 200 cubic feet per minute with two primary inlet
`sources and a negative air machine that produces a constant flow during the workplace
`study. After the study, the inside of the chamber was decontaminated by standard
`asbestos decontamination methods including HEPA vacuuming of all dust and debris
`and wet wiping of all surfaces.
`During video taping of the work practice study, lighting is utilized inside the chamber to
`enhance the possibile observations of dust release during the work practice. Previous
`studies have shown that the use of, what is commonly referred to, as the “Tyndall light
`phenomena” is an effective method of displaying respirable airborne dust generated
`from workplace actives.!24
`A grinding machine was provided to Materials Analytical Services (MAS) by Adair's
`Machine Service, Inc. The grinding machine was a Cincinnati #2 Tooling and Cutter
`Grinder. Ben Adair of Adair’s Machine Service also provided two tungsten carbide (C-2
`grade) strips (%" x %" x 6"). A (7"x%") Carborundum Black Magic Diamond grinding
`wheel was provided to MAS by Mr. Thomas Tardy of Forman, Perry, Watkins, Krutz, &
`Tardy, PLLC.
`During the study, air samples were collected using 25mm air cassettes containing 0.8
`micron pore mixed cellulose ester (MCE) filters and a 5.0 micron backing pad. The air
`sampling pumps were calibrated both before and after the sample collection. - High |
`volume pumps were used for area or bystander air samples during the simulation. The
`pumps were located outside the chamber and connected to the air sample cassettes by
`Tygon tubing through the wails of the chamber. The three area air samples were
`located near the North, South, and West walls of the chamber. The air sampling
`cassettes were located approximately five feet from the floor and 5 to 8 feet from the
`work activity. The high volume pumps were calibrated to a flow rate of 10 liters per
`minute. The machinist performing the work place simulation as well as the two
`investigators observing the work were each fitted with two personnel air samplers
`attached to the left and right shoulder area to sample in the breathing zone during the
`' Surgen Commander, P.G. Harris, “The Effects and Control of Disease Associated with Exposure in Devonport
`Dockyard.” Doctoral Dissertation.
`~ C. Dermchi & K.5. Lane, “Asbestos Toxicology Report,” Union Carbide Corporation.
`~ D.T, Chambers, “Dust Control Development in Asbestos”, Volume 2, Properties, Applications, and Hazards, p.
`193, 1983.
`
`\*
`
`

`

`FILED: NEW YORK COUNTY CLERK 01/29/2024 07:20 PM
`NYSCEF DOC. NO. 188
`
`work place simulations. The personnel air samples were collected with battery operated
`Gillian pumps, calibrated to a flow rate of 2 liters per minute. Before each work place
`simulation, background samples were run both inside and outside the chamber. The air
`samples were collected in general accordance with methods outlined in NIOSH’s 582
`“Sampling and Evaluating Airborne Asbestos Dust”.
`The individuals working inside the chamber wore Tyvek suits under cotton/polyester
`work cloths and were protected with either Powered Air Purifying Respirators or Self-
`Contained Breathing Apparatus (SCBA). The chamber design included
`decontamination areas for clothing removal and for a shower to remove any residual
`asbestos contamination before the workers left the chamber area. A fabric sample from
`the work clothes of the machinist was collected to measure for any possible asbestos
`contamination.
`The work practice studied was the grinding of the tungsten carbide strip with a
`Carborundum Black Magic Diamond Wheel. Mr. Ben Adair installed the grinding wheel
`on the grinding machine and set-up the tungsten carbide strip for grinding. The %”
`surface of the strip was the surface which was ground. Mr. Ben Adair, who has 18
`years experience as a machinist, operated the grinding machine during the work
`practice study. During the grinding, the strip was passed under the grinding wheel
`along the 6” length of the strip. The %" edge was ground a number of times 1/1000”
`each time. Fifteen or more passes were necessary to complete a removal of 1/1000”
`from the %” edge. The diamond grinding wheel required cleaning periodically
`throughout the process. The cleaning was performed by placing an aluminum oxide bar
`in contact with the wheel.
`_ The filters were analyzed by the NIOSH 7400 method for PCM using A counting rules.
`The TEM air samples for analysis were prepared using a redeposit method as detailed
`in the ASTM method D-5595. For TEM analysis, a modified Yamate EPA level fl indirect
`air sample analysis was performed. The fabric sample collected from Mr. Adair’s work
`clothes was analyzed by the Chatfield method.
`Samples of the grinding surface and from the hub of the grinding wheel were removed,
`were collected after the completion of the study. These samples were analyzed by
`Polarized Light Microscopy (PLM) to determine the asbestos content. Upon completion
`of the workplace simulation study, the chamber was compietely decontaminated. The
`black cloth sheeting on the inside surfaces of the chamber was removed and disposed.
`All surfaces were HEPA vacuumed and wet wiped according to standard asbestos
`abatement technology.
`*
`
`INDEX NO. 190088/2021
`
`RECEIVED NYSCEF: 01/29/2024
`
`