Refractory ceramic fiber (RCF) products have been manufactured and used extensively for more than 40 years and there’s no evidence of any exposure-related, disease. While this is comforting to manufacturers, processors, and end users, regulatory agencies are encouraging the RCF industry to continue its efforts in reducing exposuress associated with RCF use. On Feb. 11, 2002, the Refractory Ceramic Fibers Coalition (RCFC), with the endorsement of the Occupational Safety & Health Administration (OSHA), launched PSP 2002. This is the RCF industry’s most recent version of its product stewardship program, expanded and updated through significant cooperation with OSHA into a voluntary worker protection program designed to control and reduce workplace exposures to RCF.

At the launch, OSHA Administrator John Henshaw endorsed PSP 2002, saying, "This is an ambitious product stewardship effort and we’re proud to support it. …the Coalition and its members are to be commended for their leadership and, on a voluntary basis, taking steps to help assure refractory ceramic fiber products are handled properly and workers are protected."

One of the most important issues confronting businesses today is the need to identify workplace hazards and find ways to reduce them. Synthetic vitreous fibers (SVF), in particular, have prompted some concern because of the adverse human health effects often associated with certain naturally occurring fibers. Over the past two decades SVFs have been subjected to extensive health and safety research by the industrial and academic communities and this research has been thoroughly reviewed by regulatory authorities throughout the world.

RCF, an aluminosilicate fiber, is a member of the SVF group of man-made products, as are fibrous glass and mineral wool. Like other SVFs, these RCFs are produced under highly controlled conditions using a melt fiberization process. A variety of product forms can be manufactured, including bulks, blankets, vacuum-formed shapes, modules, papers and cements. RCFs represent the smallest portion of the SVF industry, accounting for less than 2 percent of the total worldwide production.

RCFs are lightweight, efficient thermal insulators with a low heat storage capacity, and outstanding thermal shock resistance. They’re used primarily in high temperature industrial applications such as furnaces, boilers, reactors or other heating equipment where temperatures may reach 2800 degrees F. Because of its high service temperature and impressive physical properties, RCF is also finding increased usage as thermal insulation in construction, aerospace, automotive, fire protection and appliance applications where, in general, the material is contained or encapsulated.

Globally, RCFs play an important energy-efficient role by controlling high temperatures and by reducing fossil fuel consumption in industrial processes by as much as 50 percent. RCFs also help to maintain product quality by maintaining proper unit operating temperatures. Finally, RCFs promote safe working conditions by protecting workers exposed to heat from high temperature processes.

Health Effects Research

Ongoing studies of current and former workers in the RCF industry have found no disease due to RCF exposure.

Inhalation toxicology studies, provide information for assessing a potential human health hazards. Between 1988 and 1992 the SVF industry contracted with Research & Consulting Company (RCC) in Geneva, Switzerland, to develop comprehensive investigations that included animal inhalation bioassays and tissue dose modeling, the results of which would later be used to develop a scientifically-based risk assessment model.

The RCC inhalation bioassays were designed to ensure careful control of the fiber size being studied, the dose administered and the methods used to evaluate the biologically effective dose to the target tissue. The maximum tolerated dose (MTD) study using hamsters and rats indicated that chronic, nose-only exposure to extremely high concentrations (approximately 200 fibers/cubic centimeter [(f/cc]) of specially-processed RCF could produce progressive lung damage (fibrosis), lung tumors, and pleural cancer (mesothelioma). A subsequent review of the MTD pathology and recent short term studies have concluded that the test animals’ lungs were significantly "overloaded" because of the presence of large quantities of non-fibrous particles, and that this overload condition may have been responsible for the disease observed.

In contrast, rats exposed in the multidose phase of the RCC study at doses of 25, 75 or 115 f/cc showed no statistically significant increase in lung tumor development and minimal or no fibrosis development.

To determine possible human health effects following RCF exposure, RCFC engaged the University of Cincinnati (UC) to conduct a long-term study on RCF workers. This ongoing study collects data from questionnaires, lung function tests, chest X-rays, exposure monitoring and worker mortality. While the incidence of respiratory changes in workers exposed to historic levels of RCF is higher than that found in unexposed individuals, the observed reversible changes are no different from those experienced by employees working in other dusty environments. Moreover, current levels of occupational exposure to RCF haven’t affected lung function. The incidence of pleural plaques, recognized as a marker of exposure but not disease, is statistically higher than background rates, but clinically insignificant. While the number of older workers in this study is small, no unusual trends in fiber related causes of death or any elevated incidence of lung disease have been observed and there have been no reports of mesothelioma.

The findings of two similar studies conducted by the Institute of Occupational Medicine (IOM) in Europe were generally consistent with the UC findings.

Regulatory Review

Environmental Protection Agency (EPA)

In the early 1990s, RCFC submitted the results of its RCC toxicology studies to EPA under the requirements of the Toxic Substances Control Act ("TSCA") and EPA began an assessment of the potential hazards and risks associated with the manufacture and use of RCF. In November 1991, EPA initiated a priority review of RCF pursuant to Section 4(f) of TSCA. On May 14, 1993, EPA and RCFC signed a five-year voluntary Consent Agreement. The agreement required RCFC to perform exposure monitoring to estimate average workplace concentrations, to study time trends and to compare estimated exposures across functional job categories.

Upon completion of the agreement, it was mutually determined that atmospheric RCF emissions were quantitatively small and of negligible risk to the general public and that future initiatives should focus on managing workplace exposures. EPA also praised the industry’s product stewardship program, calling it a "model for other industries."

National Institute for

Occupational Safety and Health (NIOSH)

In the 1980s and 1990s, NIOSH conducted health hazard evaluations at power plants and foundries that use RCFs. RCFC continues to partner with NIOSH to evaluate engineering controls and work practices to reduce RCF exposures in the absence of conclusive data regarding possible risks associated with its use.

Occupational Safety and Health Administration (OSHA)

In June 1992, OSHA proposed amendments to its permissible exposure limits (PELs) for a large number of air contaminants, which included a PEL of 1 f/cc for SVFs. Shortly thereafter, the United States Court of Appeals for the 11th Circuit vacated the air contaminants rule, holding that OSHA was required to perform independent risk and feasibility analyses before it could adopt any PEL. Today there’s still no PEL for RCF.

Following the 11th Circuit decision, in August 1994, OSHA announced a "Priority Planning Process" designed to prioritize the agency’s resources for standard setting. In December 1995 OSHA identified SVFs as one of the substances it viewed as a priority and stated it endorsed "voluntary approaches [that] seek to correct workplace hazards through cooperative actions." In May 1999, the North American Insulation Manufacturers Association (NAIMA), a trade association representing fibrous glass and mineral wool manufacturers, submitted its voluntary partnership program to OSHA entitled, "Health & Safety Partnership Program." At the same time, the National Insulation Association submitted its voluntary "Contractor Health and Safety Partnership Program" to OSHA. RCFC’s PSP 2002 represents another voluntary program that addresses the RCF portion of the SVF family.

Product Stewardship Program (PSP 2002)

In 1990, RCFC and its member companies initiated their comprehensive product stewardship program ("PSP"), which has been continuously improved since. PSP is designed to assist RCF manufacturers and end users in the evaluation, control and reduction of workplace RCF exposures. Program recommendations are intended to help ensure proper handling, manufacture, storage, use and disposal of RCF products. PSP includes: communications, workplace monitoring, evaluation of workplace controls, exposure assessments, health effects research, product research and special studies. In addition, PSP encourages implementation of workplace engineering and process controls and use of appropriate respirators and other personal protective equipment. During the past 12 years PSP has resulted in substantial reductions in RCF workplace exposures and provided a foundation for prioritizing future initiatives.

More recently, RCFC undertook the development of an updated product stewardship plan, called PSP 2002. This voluntary plan was developed with the support of OSHA, EPA and NIOSH, along with input from stakeholders representing organized labor, associated industry groups, end users and other interested parties. PSP 2002 incorporates many of the key elements of the existing highly acclaimed RCFC PSP, along with a number of new elements.

Key Features of PSP 2002

PSP 2002 applies to any operation where exposure to RCF may occur. RCFC member companies are directly responsible for compliance with PSP 2002 voluntary initiatives in their own operations. In addition, they’ll undertake activities to educate RCF end-users to encourage compliance with PSP 2002 requirements and the implications for possible regulatory oversight.

Recommended Exposure Guideline

In the absence of an RCF PEL, RCFC has adopted a recommended exposure guideline ("REG") of 0.5 f/cc, 8-hour time weighted average (TWA). This REG is based on data collected during the voluntary Consent Agreement with EPA.

The general premise of PSP 2002 is to reduce RCF exposures to the lowest feasible level. Where it’s feasible to reduce workplace concentrations below the REG, RCFC recognizes that it’s prudent to do so. Where workplace concentrations are already below the REG, RCFC recommends continued efforts to maintain and reduce exposures to the lowest levels technically and economically achievable.

The REG isn’t based on a conclusion of any relative hazard or risk; instead it’s based on a general assumption that the lower the workplace concentration, the lower the risk. A detailed and comprehensive quantitative risk assessment provides useful insight into the potential health effects of RCF exposure in the workplace (see www.rcfc.net).

Control Measures

Member companies strive to use product design, engineering controls, work practices, respiratory protection or a combination thereof to achieve worker exposure control. While engineering controls are used where feasible and necessary, other techniques may be utilized to assure worker protection. Member companies also strive to ensure that any changes to product properties don’t lead to an increased end user compliance burden.

Member companies also provide information to RCF product users regarding exposure control techniques and best practices and provide assistance to end-users to develop and implement effective exposure controls.

Work Practices

Member companies encourage employers and employees to follow proper RCF handling guidelines. RCFC provides recommended work practice guidelines, in both video and written format. These include recommendations for cost-effective engineering controls, proper respirator use, use of protective clothing and workplace handling guidelines to promote the continuous improvement of appropriate handling and use techniques for RCF products.

Worker Training

Member companies also provide health and safety training for employees consistent with OSHA Hazard Communication requirements. They also provide health and safety training to endusers. RCFC participates in trade shows, conferences and other relevant events providing suitable forums for communicating RCF-related health and safety information and guidance to end users.

Respirator Use

Member companies support OSHA’s respiratory protection standards that form the basis of the industry’s respiratory protection program. RCFC’s training programs and materials incorporate all relevant requirements of OSHA’s respiratory protection standard.

Member companies require appropriate respiratory protection when employee exposures aren’t "reliably" below the industry REG. RCFC will continue recommending the use of appropriate respiratory protection to end users in circumstances where occupational exposures may exceed industry guidelines and effective engineering controls aren’t readily available.

Medical Monitoring

Member companies maintain medical monitoring programs for their workers, consistent with accepted surveillance practices and protocols. The medical monitoring program, designed by UC physicians and epidemiologists, investigates and identifies possible RCF-related health effects. While there are no specific medical monitoring requirements for RCF, UC has incorporated study elements believed to be appropriate for a population exposed to respirable fiber dusts.

Exposure Monitoring

Member companies have an ongoing RCF exposure monitoring program in their manufacturing facilities to ensure that employee exposure is controlled and consistent with the industry’s REG.

RCFC also encourages exposure evaluation in the end users’ workplace. Member companies have trained professionals available to assist end users in determining worker exposures and advise on engineering controls, respiratory protection and proper handling practices. Employers and employees are provided with the monitoring results. If requested, member companies can also recommend independent contractors or consultants who have the appropriate skills and experience to assist with exposure monitoring. Additionally, RCFC and its member companies will continue to commit monitoring resources toward identifying best practices for engineering and process controls, along with improved handling practices.

Product Research

Member companies continue to develop new, improved RCF product forms. This product research generally focuses on three key elements-dose, dimension and durability. To reduce worker exposure potential (i.e., reduce dose), methods are being explored to contain RCF. Member companies are also investigating options to alter RCF distribution size (i.e., dimension) to reduce the respirable fraction, while maintaining key performance properties.

Consumer Products

Member companies will continue attempting to ensure that exposures in consumer product applications are well controlled. RCF use in a consumer product in a manner that may cause significant exposure, under proper use and maintenance conditions, is deemed to be inconsistent with the intent of PSP 2002.

Waste Minimization and Disposal

RCFC and its member companies continue to study, recommend and implement programs designed to reduce waste and to increase recycling rates where practicable and effective. They also continue to study after-service and solid waste handling procedures to recommend appropriate handling procedures for disposal of friable RCF wastes.

RCFC and Its Stakeholders

While member companies have effectively managed exposures in their manufacturing facilities, monitoring results have shown that, on average, RCF exposures by end user employees are approximately twice as high. Through its PSP 2002 program, RCFC is committed to reducing exposures throughout the industry to the lowest technically and economically achievable level. This will only be accomplished with stakeholder support.

The first step is to benchmark exposures through monitoring. Member companies have more than 10 years experience in monitoring RCF exposures. They’re prepared to monitor jobs directly or to assist in finding qualified industrial hygiene professionals who can be hired to undertake the work. All collected data is considered confidential and is incorporated into the RCFC database, maintained by an independent consulting firm, to provide a comparison with current industry achievable standards.

Where exposures are found to be above the industry’s REG, member companies work with their customers in recommending respiratory protection consistent with OSHA and NIOSH guidelines. As respiratory protection shouldn’t be considered a permanent solution for remediating high exposures, member companies, based on proven engineering experience, evaluate work practices and engineering controls and make recommendations that are technically and economically feasible in reducing exposures below the REG.

Often new product developments are driven by stakeholder needs. Member companies work to modify or develop new products consistent with PSP 2002’s goals of lower exposure and lower potential risk. Communication and exchanges of ideas between manufacturers and end users are critical. Additional benefits also may include environmental responsibility issues and opportunities within the RCF product’s life cycle.

Finally, while customer medical surveillance may not be a requirement of PSP 2002, stakeholders might wish to consider a program for employees that includes chest X-rays every three years.

Summary

Human health effects from SVF exposure, including RCF, have been thoroughly evaluated worldwide. To date, no disease associated with RCF exposure has been found. However, as with all workplace fiber and dust exposures, it’s prudent to reduce exposure, and therefore risk, to the lowest technically and economically achievable levels.

PSP 2002 is a voluntary program that continues many of the initiatives embraced by the industry during the past 15 years. It has been developed for use wherever RCF is manufactured, fabricated, installed or removed, as well as other occupational settings where workers might face RCF exposure. RCFC is confident that PSP 2002 addresses the key components of responsible risk management and that compliance will minimize potential risk associated with workplace exposure.

For a copy of PSP 2002 or for additional information on refractory ceramic fibers, visit our Web site: www.rcfc.net.