Document Jr8XennEqXMaDXGd43nZzZZ6X

urnWML day or is the operation short term, or perhaps a 24 hour sample might be appropriate? 3. What is the purpose of the air monitoring? Is it to determine an eight-hour time weighted average of asbestos exposure, a short term (15 minute) exposure or to determine background levels of asbestos in air? 4. If background levels of asbestos are sought, to what lower level of concentration is it desired to accur ately measure the asbestos in air? We will be talking in more detail about the types of filter, how air is drawn through them and how the Asbestos construction materials Inside a building can dramaUcally af fect the real estate value of the structure as well as the health of Its oc cupants and visitors. Asbestos abatement Is a complicated and costly procedure prone to disaster If not properly performed. SourceFlnders Information Corporation, an eight-year-old research, publishing and video production firm. Is North America's largest private supplier of as bestos safety Information. Our video programs and books cover all as pects of asbestos-tn-bulldlngs problems. Professionally written and pro duced. the programs In our Asbestos Safety Workshop video series are priced at $69.95 in VHS & BETA formats. SourceFlnders' asbestos safe ty educational materials are now utilized by such organizations as the Smithsonian InsUtute, NASA, the U.S. Army Corps of Engineers, Chase Manhattan and Paramount Pictures. For a full catalog of our asbestos videos and books, call or write today. St, SourceFinders68 Sandra Road, Voorhees, NJ 08043 609-772-23S5 Information Corporation V 16 ASBESTOS ABATEMENT MARCH/APRIL 1987 dust is analyzed. The importance of the answers to these questions will then become evident. The Filter... There are two types of filters being used today for asbestos monitoring. One is a 37 millimeter diameter (mm) filter in a three piece plastic cassette and the other is a 25 mm filter in a three piece cassette. A new NIOSH analytical procedure (method 7400) and the new OSHA standard for asbestos regulation require the use of the 25 mm system. The majority of sampling presently uses the 25 mm svstem and the new NIOSH method 7400. Both systems contain a cellulose filter and allow "open faced" samp ling. In open faced sampling, the en-. tire filter face is exposed so that air can be drawn uniformly through the entire surface area. Dust is then col lected uniformly over the entire face. The cassette is designed with a ring center section. OSHA recommends this center section be "anti-static" treated, such as coated with graphite. Most manufacturers of the 25 mm cassette provide such a center section cowl. During sampling, the top sec tion of the filter is removed and the center section cowl clamps the filter in place. After sampling, the top sec tion is again attached to protect the filter. The Pump... Personal monitoring (measuring the asbestos in air concentration of a per son while he or she works), is done using a battery operated air pump at tached to the person. Air is drawn through a filter cassette system at tached to the "breathing zone" of the person, usually attached to the collar. The pump is often clipped to a belt and connected to the cassette by a rubber hose. Air pumps are manufactured by numerous companies (such as Du Pont, MSA and SKC) and are similar in design. A battery pack, charged overnight, will run the pump for eight to ten hours. Air is drawn at the rate of 1 to 4 liters per minute (1/m). The air Bow is maintained at a pre-set flow GLEASON-001138