Johns Manville

About: Johns Manville is a based out in . It is known for research contribution in the topics: Glass fiber & Fiber. The organization has 586 authors who have published 479 publications receiving 7672 citations. The organization is also known as: Johns-Manville & Johns-Manville Corporation.

Synthetic vitreous fibers : A review of toxicology research and its impact on hazard classification

Abstract: Because the inhalation of asbestos, a naturally occurring, inorganic fibrous material, is associated with lung fibrosis and thoracic cancers, concerns have been raised about the possible health effects of synthetic vitreous fibers (SVFs). SVFs include a very broad variety of inorganic fibrous materials with an amorphous molecular structure. Traditionally, SVFs have been divided into three subcategories based on composition: fiberglass, mineral wool (rock, stone, and slag wools), and refractory ceramic fiber. For more than 50 years, the toxicologic potential of SVFs has been researched extensively using human epidemiology and a variety of laboratory studies. Here we review the research and its impact on hazard classification and regulation of SVFs. Large, ongoing epidemiology studies of SVF manufacturing workers have provided very little evidence of harmful effects in humans. Several decades of research using rodents exposed by inhalation have confirmed that SVF pulmonary effects are determined by the "Three D's", fiber dose (lung), dimension, and durability. Lung dose over time is determined by fiber deposition and biopersistence in the lung. Deposition is inversely related to fiber diameter. Biopersistence is directly related to fiber length and inversely related to fiber dissolution and fragmentation rates. Inhaled short fibers are cleared from the lung relatively quickly by mobile phagocytic cells, but long fibers persist until they dissolve or fragment. In contrast to asbestos, most of the SVFs tested in rodent inhalation studies cleared rapidly from the lung (were nonbiopersistent) and were innocuous. However, several relativley biopersistent SVFs induced chronic inflammation, lung scarring (fibrosis), and thoracic neoplasms. Thus, biopersistence of fibers is now generally recognized as a key determinant of the toxicologic potential of SVFs. In vitro dissolution of fibers in simulated extracellular fluid correlates fairly well with fiber biopersistence in the lung and pulmonary toxicity, but several exceptions suggest that biopersistence involves more than dissolution rate. Research demonstrating the relationship between biopersistence and SVF toxicity has provided a scientific basis for hazard classification and regulation of SVFs. For a nonhazardous classification, legislation recently passed by the European Union requires a respirable insulation wool to have a low lung-biopersistence or be noncarcinogenic in laboratory rats. U.S. fiberglass and mineral wool industries and the Occupational Health and Safety Administration (OSHA) have formed a voluntary Health and Safety Partnership Program (HSPP) that include: a voluntary permissible exposure level (PEL) in the workplace of 1 fiber/cc, a respiratory protection program for specified tasks, continued workplace air monitoring, and, where possible, the development of fiber formulations that do not persist in the lung. RCF manufacturers have implemented a Product Stewardship Program that includes: a recommended exposure guideline of 0.5 fibers/cc; a 5-year workplace air monitoring program; and research into the development of high-temperature-resistant, biosoluble fibers.

Inorganic fiber composition

Abstract: Inorganic fibers which have a silicon extraction of greater than about 002 wt % Si/day in physiological saline solutions The fiber contains SiO 2 , MgO, CaO, and at least one of Al 2 O 3 , ZrO 2 , TiO 2 , B 2 O 3 , iron oxides, or mixtures thereof Also disclosed are inorganic fibers which have diameters of less than 35 microns and which pass the ASTM E-119 two hour fire test when processed into a fiber blanket having a bulk density in the range of about 15 to 3 pcf

Device for fencing and absorbing contaminating oil spills on water

Abstract: An elongate body of oil absorbing material and flotation material including longitudinal reinforcing or strengthening means whereby a plurality of bodies can be linearly disposed in end-to-end relationship for temporarily fencing oil spills on water for retention and absorption of the oil. The body contents comprise oil absorbing fibers - natural or synthetic or combinations thereof - and may include a flotation material interspersed therewith to aid buoyancy of the body even after saturation of the fibers by oil.