Laborers and signatory employers who work with refractory ceramic fibers (RCFs) – Fiberfax and Thermal Ceramics are common brands – should take a look at a new document from the National Institute for Occupational Safety and Health (NIOSH): Criteria for a Recommended Standard: Occupational Exposure to Refractory Ceramic Fibers.

RCFs are synthetic glass fibers. Once spun and recaptured, the fibers are formed into lightweight insulation capable of withstanding the very high temperatures in kilns, boilers and furnaces. Laborers often work with RCFs when rehabbing old furnaces. Because of the nature of the work and the enclosed space, exposures can be very high. Removing RCFs from old boilers also exposes workers to high silica levels.

Like asbestos fibers, RCFs can be breathed into the lungs where they lodge and cause respiratory problems including pleural plaques (build-up of scar tissue on the lining of the lungs) and, possibly, lung cancer and mesothelioma (a rare cancer on the lining of the lungs or abdomen). They also can cause skin and eye irritation.

This 203-page NIOSH publication reviews the studies of health effects, makes recommendations on exposure limits, suggests possible programs to reduce exposures and identifies issues with regard to RCFs that need further scientific investigation.

Some of the recommendations to follow include:

  • Provide safety training about RCF exposure and safe work practices to all exposed workers.
  • Post warning labels on the dangers and need for respiratory protection.
  • Use engineering controls like ventilation (HEPA local exhaust) or water jets for high hazard tasks like cutting and grinding. Hand sawing or sanding also reduces exposures compared with powered tools. Wet methods (water mist) are also effective in reducing exposures. Use HEPA filtered vacuums for clean up, not compressed air.
  • Shower after work. Change clothes at work to avoid taking the dust home.
  • Wear long sleeved clothing, gloves and eye protection.
  • Wear respirators to reduce exposures below 0.5 f/cc. For removal of insulation, a full-faced supplied air respirator may be needed.
  • Monitor worker exposures regularly.
  • Exposed workers should have periodic medical exams by a qualified physician or health care provider focusing primarily on respiratory health.
  • Exposed workers should quit smoking as this can significantly increase the risk of disease.

Despite the fact that most non-governmental health and safety professionals consider RCF medical risks very similar to those of asbestos, NIOSH recommends a RCF exposure limit (0.5 fibers/cc of air as an eight-hour time weighted average) that is five times the OSHA asbestos limit.  It also is more than twice the RCF limit recommended by the American Conference of Governmental Hygienists (ACGIH).  NIOSH concedes that there may still be a cancer risk at its recommended limit, so the LHSFNA urges Laborers and employers to keep RCF exposures as low as possible.

LHSFNA Occupational Safety and Health Division Director Scott Schneider served on a review panel for the document. It can be ordered from NIOSH. The OSH Division and its professional staff can help local unions and signatory employers develop company- or job-specific RCF safety programs. For assistance, contact the Division at 202-628-5465.