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Environmental Control for Tuberculosis: Basic Upper-Room Ultraviolet Germicidal Irradiation Guidelines for Healthcare Settings

Related Materials

• Peer Reviewers’ Comments [PDF - 24 KB]
• Response to Peer Reviewers’ Comments [PDF - 22 KB]

Required Elements for Initial Public Posting

Title: Environmental Control for Tuberculosis: Basic Upper-Room Ultraviolet Germicidal Irradiation Guidelines for Healthcare Settings

Subject: Evaluation of upper-room ultraviolet irradiation systems to remove Mycobacterium tuberculosis

Purpose: To reduce the potential exposure of health care workers (and the general public) to tuberculosis

Timing of Review: Early 2005

Primary Disciplines or Expertise Needed for Review: Engineering, health science, industrial hygiene

Type of Review: Individual

Number of Reviewers: 13

Reviewers Selected by: NIOSH

Public Nominations Requested for Reviewers: No

Opportunities for the Public to Comment: No

Peer Reviewers Provided with Public Comments Before Their Review: No

Peer Reviewers:

Peter Broden
Organizational Affiliation: R&D Manager - Applied Research, Research and Development, Underwriters Laboratories, Inc., Northbrook, IL
Areas of Expertise, Discipline, or Relevant Experience: Provided insight into the Underwriters Laboratories (UL) process for approving equipment such as UVGI fixtures
Recommended by: NIOSH

Lloyd Chapman
Organizational Affiliation: Philips Lighting Company, Somerset, NJ
Areas of Expertise, Discipline, or Relevant Experience: UVGI lamps
Recommended by: NIOSH

David Dubiel
Organizational Affiliation: Associate Research Engineer, Research and Development, Underwriters Laboratories Inc., Northbrook, IL
Areas of Expertise, Discipline, or Relevant Experience: Provided insight into the Underwriters Laboratories (UL) process for approving equipment such as UVGI fixtures
Recommended by: NIOSH

Charles Dunn Sr.
Organizational Affiliation: President, Commercial Lighting Design, Inc. (Lumalier), Memphis, TN
Areas of Expertise, Discipline, or Relevant Experience: Mr. Dunn’s company manufacturers and installs upper-room UVGI fixtures, including fixtures that were used in the NIOSH-funded study at the University of Colorado
Recommended by: NIOSH

Melvin First
Academic and Professional Credentials: Ph.D.
Organizational Affiliation: Professor Emeritus of Environmental Health Engineering, Department of Environmental Health, Harvard University
Areas of Expertise, Discipline, or Relevant Experience: Designed and operates a facility for conducting tests to evaluate the effectiveness of upper-room UVGI systems against tuberculosis surrogates
Recommended by: NIOSH

Wladyslaw Kowalski
Academic and Professional Credentials: Ph.D., P.E.
Organizational Affiliation: Research Associate Department of Architectural Engineering The Pennsylvania State University
Areas of Expertise, Discipline, or Relevant Experience: Dr. Kowalski has published numerous articles on UV germicidal irradiation and is considered an expert in mathematical modeling and design of UVGI systems
Recommended by: NIOSH

Kevin Landkrohn
Academic and Professional Credentials: M.S.
Organizational Affiliation: Industrial Hygienist, Occupational Safety and Health Administration, U.S. Department of Labor; Member of the CDC Advisory Council for the Elimination of Tuberculosis and the ACGIH Infectious Agents Committee
Areas of Expertise, Discipline, or Relevant Experience: Industrial hygiene; also provided insight into OSHA’s perspective on TB and upper-room UVGI systems
Recommended by: NIOSH

Shelly Miller
Academic and Professional Credentials: Ph.D.
Organizational Affiliation: Assistant Professor, Mechanical Engineering Department, University of Colorado at Boulder
Areas of Expertise, Discipline, or Relevant Experience: Dr. Miller is the lead researcher on the NIOSH contract that formed the basis of the NIOSH guideline document and is an expert on the installation and use of upper-room UVGI systems
Recommended by: NIOSH

Edward Nardell
Academic and Professional Credentials: M.D.
Organizational Affiliation: Associate Professor, Departments of Environmental Health and Immunology and Infectious Diseases, Harvard University
Areas of Expertise, Discipline, or Relevant Experience: Currently involved in ongoing research projects on the effectiveness of various controls for tuberculosis, including upper-room UVGI systems
Recommended by: NIOSH

Paul Ninomura
Academic and Professional Credentials: B.S., P.E.
Organizational Affiliation: Mechanical Engineer, Indian Health Service, Seattle, WA; Serves on several ASHRAE committees
Areas of Expertise, Discipline, or Relevant Experience: Co-authored the ventilation recommendations for the 2001 Guidelines for Design and Construction of Health Care Facilities
Recommended by: NIOSH

Nicholas Pavelchak
Academic and Professional Credentials: M.S., C.I.H.
Organizational Affiliation: Industrial Hygienist, New York State Department of Health
Areas of Expertise, Discipline, or Relevant Experience: Industrial hygiene; has been involved in studying hospital isolation rooms designed for tuberculosis cases
Recommended by: NIOSH

Stephen Rudnick
Academic and Professional Credentials: Sc.D.
Organizational Affiliation: Lecturer on Industrial Hygiene Engineering, Department of Environmental Health, Harvard University
Areas of Expertise, Discipline, or Relevant Experience: Specializes in aerosols, particularly in relation of sampling, analysis, and engineering control of particles in the occupational setting; present area of study is the use of upper-room UVGI systems
Recommended by: NIOSH

Michael Soganich
Organizational Affiliation: Philips Lighting Company, Somerset, NJ
Areas of Expertise, Discipline, or Relevant Experience: UVGI lamps
Recommended by: NIOSH

Charge to Reviewers:

Dear :

Enclosed for your review and comment is the draft National Institute for Occupational Safety and Health (NIOSH) technical document Engineering Controls for Tuberculosis: Upper-Air Ultraviolet Germicidal Irradiation. The draft document was developed by an interdivisional team of NIOSH scientists. It contains guidelines for designing safe and effective upper-air ultraviolet germicidal irradiation (UVGI) systems that will kill or inactivate droplet nuclei containing Mycobacterium tuberculosis.

In 1997, NIOSH awarded a contract to the University of Colorado to evaluate the ability of a well-designed and thoroughly characterized upper-air ultraviolet UVGI system to inactivate or kill airborne surrogates of M. tuberculosis. A number of parameters were evaluated during the study. These included: (1) the intensity of UVGI needed to inactivate M. tuberculosis surrogates, (2) how to best measure UVGI irradiance levels, (3) the effect of air mixing on UVGI performance, (4) the relationship between mechanical ventilation and UVGI systems, (5) the effects of humidity and photoreactivation, and (6) the optimum placement of UVGI fixtures.
The completed research clearly indicates that an appropriately designed and maintained upper-air UVGI system can inactivate or kill airborne mycobacteria and significantly increase the protection afforded to healthcare workers while maintaining a safe level of UVGI in the occupied lower portion of the room. The information obtained from this research has been combined with data from other studies to develop the guidelines.

During your review, please address the technical content only as the document will be edited after external review comments have been considered and incorporated into the document. The following is a list of specific and general questions for you to consider:

Specific Questions

1. Is the guideline provided for average UVGI intensity (30-50FW/cm²) in the upper-room air appropriate? Would it be better to use a minimum average intensity (e.g., 30 FW/cm²)? Would some other guideline be more useful?
2. Is the guideline for installing louvered fixtures that provide 0.17 UV-C watts per each ft² in a room appropriate? Is the guideline of 0.085 UV-C watts per ft² for fixtures without louvers in rooms with 9 ft or higher ceilings appropriate?
3. Other than the information provided in the draft document, what other methods are available for obtaining Aspot measurements@ of the upper-air UVGI intensity when the UVGI system is composed of multiple fixtures?
4. Is it appropriate to provide a guideline that states UV lamps should be replaced when the lamps start to emit approximately 70% of their original output? What is the best way to measure the output of the UV lamps in a fixture? Under "air mixing guidelines" it is stated in the draft that fans should be used to continually mix the air if there is any question about vertical air mixing between the upper and lower portion of a room. Will the use of mixing fans have any affect on other infection control issues?

General Questions

1. Is the information presented adequate? If not, what further information should be provided? What additional tables or graphs would you suggest?
2. What information, if any, would you delete and why?
3. Has all of the relevant information been considered for the topic(s)? If you believe other citations should be included for completeness, please identify and provide a copy of the reference(s).

Your review comments may be disclosed to outside parties if NIOSH is requested to provide this information under a Freedom of Information Act (FOIA) request.

Please return your comments to Mr. Larry Reed by , at MS R5. If you have any questions concerning this document, feel free to contact Mr. Reed at (513) 841-4592, fax (513) 841-4506, or e-mail ler3@cdc.gov.

Thank you for agreeing to participate in the external review of this document. Sincerely yours,

Mary Lynn Woebkenberg, Ph.D.
Interim Director
Division of Applied Research and Technology
Enclosure