Document R2p6Zoe1Byw4m7QVppmZBroev

FILE NAME: Hopeman Brothers (HB) DATE: 1970 May 1 DOC#: HB007 DOCUMENT DESCRIPTION: Johns-Manville Warning Info - Marinite Products-Control of Dust MT-000009 ...fl m IZ\ Division Headquarters May 1, 1970 MARINITE PRODUCTS CONTROL OF DUST The Environmental Control Department has provided the following general recommendations for customers engaged in Handling, Machining, Cutting, Grinding and Drilling of Marinite products: . 1. When machining, cutting, grinding or drilling Marinite, efficient mechanical dust control equipment should be used which will maintain the dust concentration in the work area below the Threshold Limit Value. When the use of such equipment is not feasible, respirators of an approved type should be worn by the worker. 2. The current *Threshold Limit Value for asbestos fiber dust is 5 fibers per cubic centimeter, greater than 5 microns in length. 3. Suitable respirators are those approved under the Bureau of Mines Schedule 21-B. 4. The approved respirators should be carefully maintained, ' including daily dismantling and cleaning of the unit plus replacement of the filter element whenever the breathing effort increases. 5. Marinite waste, dust or scrap pieces should not be allowed to accumulate in the work area. They should^ be disposed of in such a way as to avoid the generation or escape of dust. Dampening or wetting of such waste is recommended before its disposal. ' 6. The area should be kept clean by vacuum cleaning floors, * ledges, roof trusses, etc. The removal of dust by brushing should be avoided. (Continued) r MT-000129 PAGE TWO 7. The best standards of good housekeeping should be main tained at all times. The areas where these operations are underway should be segregated from other areas with in the building. In addition to dust control equipment, good general room ventilation should be maintained at all times. 8. Workers should wear coveralls that can be kept clean and dust free. Disposable coveralls are available and recommended. * *As set forth in the American Conference of Governmental Industrial Hygienists 1970 Notice of Intended Changes. CPW/tm TO: 761-B 21-(Billerica only) Carl P. Weber Product Manager MT-000130 PRODUCED J i - 83