The document outlines health hazards associated with man-made vitreous fibers (MMVF), emphasizing their potential risks to lung health due to inhalation of fine fibers during handling. It traces the development and application of fiberglass, noting its widespread use as insulation and a substitute for asbestos in various industries. Strict precautions and training are required for personnel handling MMVF materials to prevent exposure and ensure safety.

1. MAN MADE VITREOUS FIBER OBJECTIVES Identify the health hazards associated with exposure to man-made vitreous fiber materials. Identify potential sources of MMVF present at all shore activities. Describe the special precautions required when handling MMVF. Describe the Navy’s exposure control program

2. WHAT IS IT ALL ABOUT? Although once thought of as a safe substitute, non-asbestos man made vitreous fibers (MMVFs) are now suspected of being health hazard. MMVF’s are a group of fibrous inorganic materials, generally aluminum or calcium silicates, that are derived from rock, clay, slag, and glass.

3. WHERE DOES IT COME FROM? Unlike naturally occurring asbestos, fibrous glass and mineral wool's are man-made, spun from molten material into a fiber-like substance. MMVFs are fire and acid resistant, and as a fiber, it can be woven into cloth, such as drapes.

4. Who Developed Fiberglass Course glass was used for decoration by the ancient Egyptians. “In Egypt, the first glass we know of, as a component of faience ware, dates from as far back as the eneolithic Badarian culture at the turn of the 5th and 4th millennia BC. Glass is produced from a mixture of silica-sand, lime and soda, coloured with the copper ore malachite and fused at a high temperature.” (excerpt and graphic are from the web site http://www.us.sis.gov.eg/pharo/html/glassfrm.htm

5. Who Developed Fiberglass The idea of fiberglass was invented by Frenchman René de Réaumur in 1713. It was refined by the process of spinning & weaving glass fibres in 1836 by another Frenchman, Dubus-Bonnel. 1931-1939 Owens Illinois Glass company and the Corning Glass works developed

6. Who Developed Fiberglass Practical methods of making fiberglass commercially. Once the technical problem of drawing out the glass threads to a fraction of their original thinness was solved the industry began to produce glass fibers for thermal insulation and air filters. Fiberglass combined with epoxy resins and thermosetting polyesters are now used extensively by the boat and ship construction, sporting goods, autos, etc…

7. MMVF have been used for decades as house insulation and as a less hazardous substitute for asbestos thermal insulation. The link of MMVFs with serious diseases lead to the limits on MMVF exposure.

8. Who Developed Fiberglass MMVF are widely used for thermal and acoustical insulation and as reinforcement materials. MMVF products have replaced asbestos as the primary source of insulation and lagging material. Because these materials are fibrous and bear some similarities to asbestos minerals, the concern is that the MMVF may have similar health hazard potential. Though experimental data is contradictory, the consensus is that prolonged high exposures to MMVF may lead to increased health risks.

9. Who Developed Fiberglass MMVFs Consist of Glass fibers, (fibrous glass) including glass wool, filamentous glass, and special application superfine glass. Mineral wool's, more correctly separated into rock wool and slag wool. Refractory ceramic fibers (RCF).

10. HEALTH HAZARDS Most MMVF’s are manufactured with diameters that are too thick to break off into pieces small enough to be inhaled. However. When handled during installation, removal cutting, grinding, etc., some fibers can split into thinner pieces that are small enough to breath.

11. Respirable fibers or dusts can also be produced during certain work operations: Blowing loose MMVF insulation's Removing insulation's that have been subjected to very high heat. These small fibers can cause problems if they reach the deep part of the lungs. The fibers can cause scar tissue to form (fibrosis) in the lungs. They may cause tumors. It has been shown in laboratory animals but not proven in humans

12. It does not appear as harmful as asbestos. There is concern that ongoing research may show a link between MMVF and other respiratory diseases. Though not as serious, MMVF are known for their ability to cause skin irritation, itching, and rashes.

13. IDENTIFICATION OF MMVF Asbestos has been used extensively in older buildings. Over the years some of this asbestos has been replaced with non-asbestos MMVF material. The only way to determine if material contains asbestos is to send it to a lab and test the material under a microscope.

14. MMVFs visibly are usually: Yellow or Pink spun glass (like your home insulation) White, yellow or grayish loose or batting mineral wool White solid ceramic material

15. CONTROL OF MMVF EXPOSURES Personnel are not authorized to remove or handle MMVF material unless they are trained in the hazards and provided with protective equipment Employees seeing a potential MMVF hazard (torn or open lagging) should report the hazard to their supervisor immediately.

16. CONTROL OF MMVF EXPOSURES Never remove any acoustical material or disturb any insulation unless you know that all environmental checks have been conducted to ensure that asbestos or lead are not a factor. If the MMVF poses a health hazard as evaluated by an Industrial Hygienist, Personnel assigned to work with MMVF may be placed under medical surveillance.

17. PERSONAL PROTECTIVE EQUIPMENT Special protection is required to work with MMVF, similar to asbestos protective equipment. All personnel working with MMVF materials shall wear safety glasses or goggles with side shields. Long sleeved clothing shall be worn.

18. In Summary MMVF materials are used in all areas of industry. Activities are required to have applicable workers trained in the proper handling of MMVF. All personnel must obtain and properly use necessary protective clothing and equipment for working (installation, repair, or removal) of material containing MMVF.