Refractory Ceramic Fibers

This criteria document provides information and recommendations for controlling occupational exposures (engineering controls, personal protective equipment, and a recommended exposure limit) to a manufactured fiber that has been identified as a potential occupational carcinogen.

Material Under Consideration

Criteria for a Recommended Standard: Occupational Exposure to Refractory Ceramic Fibers; DHHS (NIOSH) Publication No. 2006-123 – May 2006 [PDF – 7,003 KB]

Reviews

Peer Review Comments on draft RCF Criteria Document – posted December 31, 2009 [PDF – 108 KB]

NIOSH Responses to Peer Review Comments – posted December 31, 2009 [PDF – 118 KB]

Peer review

Title: Criteria for a Recommended Standard: Occupational Exposure to Refractory Ceramic Fibers

Subject: A comprehensive analysis and critical review of the literature and an assessment of the hazards of occupational exposure to airborne refractory ceramic fibers.

Purpose: To provide information and recommendations for controlling occupational exposures (engineering controls, personal protective equipment, and a recommended exposure limit) to a manufactured fiber that has been identified as a potential occupational carcinogen.

Timing of Review: Formal review was performed February through June 2003

Primary Disciplines or Expertise Needed for Review: Risk assessment, toxicology, epidemiology, industrial hygiene

Type of Review: Individual

Number of Reviewers: 5

Reviewers Selected by: NIOSH

Public Nominations Requested for Reviewers: No

Opportunities for the Public to Comment: Yes

Peer Reviewers Provided with Public Comments: Yes

Peer Reviewers:

John Cherrie, Ph.D.
Department of Environmental and Occupational Medicine
Liberty Safe Work Research Centre, Aberdeen, United Kingdom
Areas of Expertise, Discipline, or Relevant Experience: Professor, member of the Institute of Medicine, and international expert in the area of exposure assessment methods and the toxicity of airborne fibers.
Recommended by: NIOSH

John Dement, Ph.D., CIH
Duke University Medical Center, Durham, North Carolina
Areas of Expertise, Discipline, or Relevant Experience: Professor in the field of occupational and environmental hygiene, industrial hygienist and international expert in the area of exposure assessment and the toxicology of airborne fibers.
Recommended by: NIOSH

Morton Lippmann, Ph.D., CIH
New York University, School of Medicine, Tuxedo, New York
Areas of Expertise, Discipline, or Relevant Experience: Professor, industrial hygienist, and international expert in the areas of fiber toxicology and exposure assessment.
Recommended by: NIOSH

Peter McClure, Ph.D., D.A.B.T.
Syracuse Research Corporation, North Syracuse, New York
Areas of Expertise, Discipline, or Relevant Experience: Research Consultant, Diplomate of the Board of Toxicologists, and author of the ATSDR Toxicological Profile on Synthetic Vitreous Fibers (under contract from ATSDR).
Recommended by: NIOSH

Jolanda M. Rijnkels, Ph.D.
Health Council of the Netherlands, Den Haag, Netherlands
Areas of Expertise, Discipline, or Relevant Experience: International expert on setting occupational exposure limits for potentially hazardous substances.
Recommended by: NIOSH

Charge to Peer Reviewers:

Overall

• Is there consistency throughout the text?
• Please comment on how accurately and clearly information is presented in the document.
• Is there adequate presentation of original data? Are there additional concerns, issues, or research areas which should be considered?
• Assess the organization of sections and chapters and provide comment.

Human studies

• Please provide a copy of any important reference that should be incorporated into these sections of the document.
• Have the important medical endpoints been adequately discussed?
• Assess the presentation and comparison of data from the U.S. and European cohorts.
• Is the discussion adequate?

Exposure assessment

• Please provide a copy of any important reference that should be incorporated into these sections of the document. Are there additional studies or data characterizing exposure to RCF which should be included?
• What is your impression of the presentation of the exposure data?
• Please identify any data gaps or suggest recommendations for further characterization of RCF exposures.

Animal and in vitro studies

• Please provide a copy of any important reference that should be incorporated into these sections of the document.
• Are the animal studies accurately described and summarized?
• Comment on any additional information that should be included regarding the Maximum Tolerated Dose discussion in the rat chronic inhalation study.
• Comment on any additional information that should be included regarding the association of particle to fiber ratio with tumor formation in the chronic inhalation studies.
• Comment on the NOAEL values presented for fibrosis and lung cancer.
• Comment on the validity of the RCF/amosite comparison using data from two different chronic inhalation studies. Please provide any additional data that should be provided in this comparison.
• Is the discussion of the animal studies adequate? If not, comment on additional information that should be included.
• Are the in vitro studies adequately summarized and explained?
• Is the discussion of the in vitro sections adequate? If not, comment on additional information that should be included.

Basis for the standard

• Is the derivation of the REL adequately explained?
• Assess the use of data collected during the EPA consent agreement to characterize exposure levels in RCF industries and determine achievable levels given engineering controls, work practices, and other considerations. Please provide suggestions or alternative approaches which might improve the presentation, interpretation, and use of these data.
• Are there additional data that should be presented in support of the REL?

Worker protection/recommendations

• Please comment on the recommendations respirator use.
• Are there other engineering controls, work practices, or other factors that should be discussed? (Please specify.)

Medical monitoring

• Please comment on the overall presentation of the medical monitoring program. Is it presented in a logical manner?
• Are there specific elements of the program which should be modified?
• Are there additional elements which could be implemented to help ensure the safety and health of workers?