Crystalline silica in heated man-made vitreous fibres: a review

Regul Toxicol Pharmacol. 2014 Feb;68(1):152-9. doi: 10.1016/j.yrtph.2013.11.014. Epub 2013 Dec 1.

Abstract

Refractory ceramic fibres (RCF) and alkaline earth silicate (AES) wools are types of man-made vitreous fibre (MMVF) that are used in demanding high-temperature industrial applications, generally above 900 °C and up to 1400 °C. When exposed to prolonged high temperatures, MMVF can devitrify with the formation of cristobalite and other crystalline silica species, which is of potential concern because crystalline silica (CS) is classified as carcinogenic. This article reviews the chemico-physical processes and morphological consequences of fibre devitrification, the forms and micro-location of CS produced, and the toxicity of devitrified fibres and the CS species formed in this way. It also examines scenarios for worker exposure to the products of fibre devitrification in industries using RCF and/or AES wools. We identify gaps in knowledge and make recommendations for future research.

Keywords: Cristobalite; Crystalline silica; Devitrification; Man-made vitreous fibres; Refractory ceramic fibres.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Animals
  • Crystallization
  • Hot Temperature
  • Humans
  • Mineral Fibers / analysis*
  • Mineral Fibers / toxicity
  • Occupational Exposure / analysis
  • Silicon Dioxide / analysis*
  • Silicon Dioxide / toxicity

Substances

  • Mineral Fibers
  • Silicon Dioxide