Direct-reading instruments are valuable tools for detecting and measuring worker exposure to gases, vapors, aerosols, and fine particulates suspended in air. These instruments permit real-time or near real-time measurements, and their use is specifically required by some OSHA standards. There are many types of instruments available, each of which is designed for a specific monitoring purpose. Proper operation of direct-reading instruments is essential to ensure that accurate information is obtained when evaluating air contaminants.

Direct-reading instruments are addressed in specific standards for the general industry, shipyard employment, and the construction industry.

OSHA Standards

This section highlights OSHA standards, standard interpretations (official letters of interpretation of the standards), and other resources related to direct-reading instruments in the workplace.

Note: Twenty-five states, Puerto Rico and the Virgin Islands have OSHA-approved State Plans and have adopted their own standards and enforcement policies. For the most part, these States adopt standards that are identical to Federal OSHA. However, some States have adopted different standards applicable to this topic or may have different enforcement policies.

         General Industry (29 CFR 1910)

• 1910 Subpart H, Hazardous materials [related topic page]
  • 1910.120, Hazardous waste operations and emergency response. Direct-reading instruments are an important element of the monitoring program outlined by this standard. [related topic page]
    
• 1910 Subpart J, General environmental controls
  • 1910.146, Permit-required confined spaces. Confined spaces must be tested before entry with a direct-reading instrument for oxygen content, flammable gases and vapors, and toxic contaminants. [related topic page]
    
• 1910 Subpart R, Special industries
  • 1910.269, Electric power generation, transmission, and distribution. Direct-reading instruments are required to test for oxygen-deficient atmospheres and flammable gases and vapors. [related topic page]
  • 1910.272, Grain handling facilities. Requires that the atmospheres of bins, silos, and tanks are tested before entry. [related topic page]
    • Appendix A, Grain handling facilities. It specifically states that direct-reading instruments should be used to periodically monitor atmospheres in bins, silos, and tanks.

Shipyard Employment (29 CFR 1915)

• 1915 Subpart B, Confined and enclosed spaces and other dangerous atmospheres
  • 1915.12, Precautions and the order of testing before entering confined and enclosed spaces and other dangerous atmospheres. Includes similar requirements to 29 CFR 1910.146.

Construction Industry (29 CFR 1926)

• 1926 Subpart D, Occupational health and environmental controls
  • 1926.65, Hazardous waste operations and emergency response. Contains requirements identical to 29 CFR 1910.120 regarding direct-reading instruments used in construction.

Standard Interpretations

• Interpretation concerning 1910.120 requirements for air monitoring, a site safety and health plan, training, and medical surveillance. (1988, August 19). Identifies colorimetric indicator tubes as a useful and acceptable approach for selected hazardous substances as a component of the air monitoring plan tailored to site specific conditions.

Other Resources

• EPA/Labor Superfund Health and Safety Task Force: OSHA Audits of Superfund Sites from 1993 to 1996. OSHA, (1997, August 25).
  


• OSHA Compliance Issues: Correcting Common Health And Safety Program Deficiencies At Remediation Sites. OSHA, (1996, June). Includes some discussion regarding the appropriate use of direct-reading instruments.
  


• Summary report on OSHA inspections conducted at superfund incinerator sites. OSHA, (1993, September 16). Describes inspections that evaluated the use of direct-reading methods as part of the exposure assessment program.

Evaluation

The following references provide information regarding methods and means used to evaluate workplace exposures with direct-reading instruments.

Sampling and Analysis

• Carbon Monoxide in Workplace Atmospheres (Direct-Reading Monitor). OSHA Method ID-209, (1993, March). Includes evaluation information for the direct-reading monitor utilized by the method.
  


• Carbon Dioxide Backup Data Report. OSHA Method ID-172, (1990, June). Includes comparison methods that utilized detector tubes and a portable infrared gas analyzer.
  


• Chemical Sampling Information. OSHA. Includes information on direct-reading methods for a given chemical.
  


• NIOSH Manual of Analytical Methods (NMAM). US Department of Health and Human Services (DHHS), National Institute for Occupational Safety and Health (NIOSH) Publication No. 94-113, (1994, August). Provides useful information on methods, quality assurance, method evaluation, biological monitoring, aerosols, and special measurement considerations. The following NIOSH methods utilize direct-reading techniques:
  • Benzene by portable GC [19 KB PDF, 4 pages]. Method No. 3700.
  • Trichloroethylene by portable GC [16 KB PDF, 3 pages]. Method No. 3701.
  • Ethylene oxide by portable GC [26 KB PDF, 4 pages]. Method No. 3702.
  • NIOSH Numbered Publications. National Institute for Occupational Safety and Health (NIOSH). Provides listing of NIOSH publications. Those that are not available online but can be ordered by calling 1-800-CDC-INFO (1-800-232-4636) or by e-mailing the NIOSH Publications Office.
    • Components for Evaluation of Direct-Reading Monitors for Gases and Vapors. Publication No. 2012-162, (2012, August).
    • Addendum to Components for Evaluation of Direct-Reading Monitors for Gases and Vapors: Hazard Detection in First Responder Environments. Publication No. 2012-163, (2012, August).
    • Evaluation of Portable, Direct-Reading Combustible Gas Meters. Publication No. 74-107, (1974).
    • Evaluation of Portable, Direct-Reading NO₂ Meters. Publication No. 74-108, (1974).
    • Evaluation of Portable-Reading Sulfur Dioxide Meters. Publication No. 75-105, (1975).
    • Evaluation of Portable, Direct-Reading Carbon Monoxide Meters. Publication No. 75-106, (1975).
    • A theoretical and laboratory evaluation of a portable, direct-reading particulate mass concentration instrument. Publication No. 76-114, (1976).
    • Evaluation of Portable, Direct-Reading Ozone Meters. Publication No. 76-132, (1976)
    • Evaluation of Portable, Direct-Reading NO-NO_X Meters. Publication No. 76-161, (1976).
    • Evaluation of Portable, Direct-Reading Hydrocarbon Meters. Publication No. 76-166, (1976).
    • Evaluation of Portable, Direct-Reading Mercury Vapor Meters. Publication No. 76-167, (1976).
    • An Evaluation of Portable, Direct-Reading H₂S Meters. Publication No. 77-137, (1977).

Video Exposure Monitoring (VEM)

With this technique, worker exposures are monitored with direct-reading instruments while workplace activities are simultaneously recorded on videotape.

• Analyzing Workplace Exposure Using Direct Reading Instruments and Video Exposure Monitoring Techniques. US Department of Health and Human Services (DHHS), National Institute for Occupational Safety and Health (NIOSH) Publication No. 92-104, (1992, August). Contains information on techniques, equipment, data analysis, and also includes case studies.
• A program that generates a graphical representation of a worker's exposure. The program reads a real-time data file, generates a bar (216 KB ZIP^*) or plot (226 KB ZIP^*) to represent the magnitude of the exposure, and then display the bar or plot on the screen. When the program is run through a video overlay system, a video recording graphically shows how a worker's exposure is influenced by work activity.
  
• National Institute for Occupational Safety and Health (NIOSH). Provides studies that utilized video exposure monitoring techniques as part of the assessment process.
  • Control Technology for Autobody Repair and Painting Shops at Church Brother's Collision Repair, Greenwood, Indiana. Report No. ECTB 179-11a, (1992, March).
  • Control Technology for Autobody Repair and Painting Shops at Kay Parks/Dan Meyer Autorebuild, Tacoma, Washington. Report No. ECTB 179-12a, (1992, September).
  • Control Technology for Autobody Repair and Painting Shops at Valley Paint and Body Shop, Amelia, Ohio. Report No. ECTB 179-14a, (1993, May).
  • Control Technology for Autobody Repair and Painting Shops at Jeff Wyler Autobody Shop, Batavia, Ohio. Report No. ECTB 179-15a, (1993, May).
  • Control Technology for Autobody Repair and Painting Shops at Cincinnati Collision Autobody Shop. Report No. ECTB 179-16a, (1993, September 21).
  • Control Technology for the Welding Operations at Boilermaker's National Apprenticeship Training School, Kansas City, Kansas. Report No. ECTB 214-13a, (1997, June 27).
  • Concentration of Metalworking Mists Before and After Installation of a Commercial Air Cleaner at Sauer-Sundstrand Company, Ames, Iowa. Report No. ECTB 218-12a, (1997, July 25).
  • Characterization of Metalworking Mists During the Evaluation of a Commercial Air Cleaner at Sauer-Sundstrand Company, LaSalle, Illinois. Report No. ECTB 218-13a, (1997, July).
  • Control of Health and Safety Hazards in Commercial Drycleaners: Chemical Exposures, Fire Hazards, and Ergonomic Risk Factors. Publication No. 97-150, (1997, December). (See the Methodology section).
    
• Cooper T, Gressel G. Real-time data evaluation at a bag-emptying operation: a case study. Appl Occup Environ Hyg. 1992;7:227-30.
  


• Gressel, et al. Video Exposure Monitoring—A Means of Studying Sources of Occupational Air Contaminant Exposure, Part 1—Video Exposure Monitoring Techniques. Applied Occupational and Environmental Hygiene. 1993 Apr;8(4):334-8.
  


• Heitbrink, et al., Video Exposure Monitoring—A Means of Studying Sources of Occupational Air Contaminant Exposure, Part 2—Data Interpretation. Applied Occupational and Environmental Hygiene. 1993 Apr;8(4):339-43.
  


• Gressel MG, Heitbrink WA, et al. Advantages of real-time data acquisition for exposure assessment. Appl Ind Hyg. 1988;3(11):316-20.

Additional Information

Training

• OSHA Training Institute (OTI) Catalog Search. Provides a keyword search and catalog listing of available courses.

Other Resources

• The Industrial Environment - its Evaluation and Control. US Department of Health and Human Services (DHHS), National Institute for Occupational Safety and Health (NIOSH) Publication No. 74-117, (1973).
  
  
• American Industrial Hygiene Association (AIHA). American Industrial Hygiene Association (AIHA). Publishes manuals on the use of direct-reading instruments.
  • Aerosol Science for Industrial Hygienists. Publication No. 246-SI-96R, (1995). Includes information on direct-reading monitoring for workplace aerosols.
  • Direct-Reading Instrumental Methods for Gases, Vapors, and Aerosols. In: The Occupational Environment — its Evaluation and Control. Todd LA, editor. Chapter 9. Publication No. 252-BP-97, 1997.
  • Direct-Reading Colorimetric Indicator Tubes Manual, Second Edition. Publication No. 172-SI-93, (1993).
  • Manual of Recommended Practice for Combustible Gas Indicators and Portable Direct-Reading Hydrocarbon Detectors, Second Edition. Publication No. 158-SI-93, (1993).
  • Manual of Recommended Practice for Portable Direct-Reading Carbon Monoxide Indicators. Publication No. 175-SI-85, (1985).
• American Conference of Governmental Industrial Hygienists (ACGIH)
• Air Sampling Instruments, 9th ed. Publication No. 0031, (2001). Includes information on several types of direct-reading instruments.
• EPA Training Manual #7 - Emergency Response to Hazardous Material Incidents. Publication No. 3115 (EPA Manual 165.16). Includes information on using direct-reading instruments for evaluating and mitigating the release of hazardous materials.
  
• National Safety Council (NSC)
  • Direct-Reading Instruments for Gases, Vapors, and Particulates. In: Fundamentals of Industrial Hygiene. 5th ed. Hahne RM, editor. Chapter 17. Product No. 15148-0000, 2002.

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