Page:Niosh tb guidelines.pdf/6

Contents

 

Foreword ....................................................................................................................................................................................................................................................

iii

 

Summary ....................................................................................................................................................................................................................................................

iv

 

List of Abbreviations ....................................................................................................................................................................................................................................................

viii

 

Acknowledgments ....................................................................................................................................................................................................................................................

ix

 

I. Introduction ....................................................................................................................................................................................................................................................

1

A. Current Epidemiology and Control of Tuberculosis ....................................................................................................................................................................................................................................................

1

B. The Mandates to NIOSH in the Occupational Safety and Health Act of 1970 ....................................................................................................................................................................................................................................................

4

C. The Principle of Public Health Prudence ....................................................................................................................................................................................................................................................

5

 

II. Mode of Airborne Transmission and Potential for Worker Exposure ....................................................................................................................................................................................................................................................

6

A. Airborne Transmission of Tubercule Bacilli ....................................................................................................................................................................................................................................................

6

B. Health-Care-Facility Workers' Potential for Exposure to Tuberculosis ....................................................................................................................................................................................................................................................

8

 

III. Methods for Worker Protection—Controlling Airborne Transmission of Tuberculosis ....................................................................................................................................................................................................................................................

10

A. Previous Recommendations for Personal Respiratory Protection ....................................................................................................................................................................................................................................................

10

B. The "Hierarchy of Controls" ....................................................................................................................................................................................................................................................

10

 

IV. Considerations in the Selection of Respirators ....................................................................................................................................................................................................................................................

16

A. Nature of the Hazard to Workers ....................................................................................................................................................................................................................................................

16

B. Potential Respirator Leakage ....................................................................................................................................................................................................................................................

18

C. Hazardous Face-Seal Leakage ....................................................................................................................................................................................................................................................

19

D. Hazardous Leakage Through Filters ....................................................................................................................................................................................................................................................

22

E. Powered, HEPA-Filter Halfmask and Positive-Pressure, Air-Line, Halfmask Respirators ....................................................................................................................................................................................................................................................

23

F. Practical Disadvantages of the Recommended Respirators ....................................................................................................................................................................................................................................................

25

G. Surgical Masks and Other Disposable Particulate Respirators ....................................................................................................................................................................................................................................................

27