McConnell E E
ToxPath, Inc., Raleigh, North Carolina 27613, USA.
Regul Toxicol Pharmacol. 2000 Aug;32(1):14-21. doi: 10.1006/rtph.2000.1409.
Synthetic vitreous fibers (SVFs) are a broad class of inorganic vitreous silicates used in a large number of applications including thermal and acoustical insulation and filtration. Historically, they have been grouped into somewhat artificial broad categories, e.g., glass, rock (stone), slag, or ceramic fibers based on the origin of the raw materials or the manufacturing process used to produce them. In turn, these broad categories have been used to classify SVFs according to their potential health effects, e.g., the International Agency for Research on Cancer and International Programme for Chemical Safety in 1988, based on the available health information at that time. During the past 10-15 years extensive new information has been developed on the health aspects of these fibers in humans, in experimental animals, and with in vitro test systems. Various chronic inhalation studies and intraperitoneal injection studies in rodents have clearly shown that within a given category of SVFs there can be a vast diversity of biological responses due to the different fiber compositions within that category. This information has been further buttressed by an in-depth knowledge of differences in the biopersistence of the various types of fibers in the lung after short-term exposure and their in vitro dissolution rates in fluids that mimic those found in the lung. This evolving body of information, which compliments and explains the results of chronic animal studies clearly show that these "broad" categories are somewhat archaic, oversimplistic, and do not represent current science. This new understanding of the relation between fiber composition, solubility, and biological activity requires a new classification system to more accurately reflect the potential health consequences of exposure to these materials. It is proposed that a new classification system be developed based on the results of short-term in vivo in combination with in vitro solubility studies. Indeed, the European Union has incorporated some of this knowledge, e.g., persistence in the lung into its recent Directive on fiber classification.
合成玻璃纤维（SVFs）是一类广泛的无机玻璃硅酸盐，用于大量应用，包括隔热、隔音和过滤。从历史上看，它们根据原材料的来源或生产它们所使用的制造工艺，被归类为一些人为划分的宽泛类别，例如玻璃、岩石（石头）、矿渣或陶瓷纤维。反过来，这些宽泛类别又被用于根据其潜在的健康影响对合成玻璃纤维进行分类，例如，1988年国际癌症研究机构和国际化学品安全规划署根据当时可用的健康信息进行了分类。在过去的10 - 15年里，关于这些纤维对人类、实验动物和体外测试系统健康影响的大量新信息不断涌现。在啮齿动物身上进行的各种慢性吸入研究和腹腔注射研究清楚地表明，在给定的合成玻璃纤维类别中，由于该类别中不同的纤维成分，可能会有多种多样的生物学反应。对短期接触后各种类型纤维在肺部的生物持久性差异及其在模拟肺部液体中的体外溶解速率的深入了解，进一步支持了这一信息。这一不断发展的信息体系，补充并解释了慢性动物研究的结果，清楚地表明这些“宽泛”类别有些过时、过于简单，不能代表当前的科学认知。对纤维成分、溶解性和生物活性之间关系的这种新理解需要一个新的分类系统，以更准确地反映接触这些材料可能产生的健康后果。建议根据短期体内研究结合体外溶解性研究的结果开发一个新的分类系统。事实上，欧盟已将其中一些知识，例如在肺部的持久性，纳入其最近关于纤维分类的指令中。
