Facility Safety / PPE

OSHA recommendations to protect workers from hydrogen sulfide exposures

July 15, 2014
  • respiratorEvaluate exposure to know whether H2S gas is present and at what levels.
  • Eliminate the source of hydrogen sulfide whenever possible.
  • If the source cannot be eliminated, control exposures by:
  • Using engineering controls as the next best line of defense.
    • Developing administrative controls and safe work practices to reduce exposures to safe levels.
    • Use personal protective equipment if engineering controls and work practices alone cannot reduce hydrogen sulfide to safe levels.

Evaluate Exposure

  • Identify processes that could release or produce hydrogen sulfide. This includes identifying known sources of hydrogen sulfide and evaluating possible fire and explosion hazards. Use a Process or Job Hazard Analysis for identifying and controlling hazards (see Hazard Analysis Methodologies in OSHA's Safety and Health Management eTool).
  • Test (monitor) the air for hydrogen sulfide. This must be done by a qualified person. Use the right test equipment, such as an electronic meter that detects hydrogen sulfide gas.
  • Conduct air monitoring prior to and at regular times during any work activity where hydrogen sulfide exposure is possible. When working in confined spaces air monitoring must be conducted in accord with the applicable OSHA standards. Detector tubes, direct reading gas monitors, alarm only gas monitors, and explosion meters are examples of monitoring equipment that may be used to test permit space atmospheres.
  • Procedures for Atmospheric Testing in Confined Spaces (PDF*). OSHA Fact Sheet. Discusses the importance of evaluating the hazards of the confined space and verifying that acceptable conditions exist for entry into that space.
  • Information on general atmospheric testing methods:
  • Hydrogen Sulfide. OSHA Chemical Sampling Information webpage. Lists sampling techniques and methods for hydrogen sulfide.
  • Hydrogen Sulfide. OSHA Method 1008. Describes the collection of airborne hydrogen sulfide through specially constructed hydrogen sulfide samplers containing silver nitrate coated silica gel using a personal sampling pump.
  • NIOSH Method 6013 (PDF). Air samples are collected with a glass tube and personal sampling pump and analyzed with ion chromatography.

DO NOT rely on your sense of smell to indicate the continuing presence of hydrogen sulfide or to warn of harmful levels. You can smell the "rotten egg" odor of hydrogen sulfide at low concentrations in air. But after a while, you lose the ability to smell the gas even though it is still present (olfactory fatigue). This loss of smell can happen very rapidly and at high concentrations and the ability to smell the gas can be lost instantly (olfactory paralysis).

Control Exposures

  • Use exhaust and ventilation systems to reduce hydrogen sulfide levels. Make sure that the system is:
    • Non-sparking
    • Grounded
    • Corrosion-resistant
    • Separate from other exhaust ventilation systems
    • Explosion-proof
  • These safety measures are important because hydrogen sulfide is flammable and can corrode materials if they are not properly protected. When working in confined spaces ventilation should operate continuously and must be conducted in accord with the applicable OSHA standards.
  • Train and educate workers about hazards and controls. Training topics may include:
    • Characteristics, sources and health hazards of hydrogen sulfide
    • Symptoms of hydrogen sulfide exposure
    • Types of hydrogen sulfide detection methods and applicable exposure limits
    • Workplace practices and procedures to protect against hydrogen sulfide exposure
    • Emergency plans, locations of safety equipment, rescue techniques, first-aid
    • Confined space procedures
  • Establish proper rescue procedures to safely rescue someone from a hydrogen sulfide exposure.
  • WARNING: First responders must be trained and properly protected before entering areas with elevated levels of hydrogen sulfide.
  • Rescuer protection should include:
    • Positive-pressure, self-contained breathing apparatus (SCBA).
    • A safety line to allow for rapid exit if conditions become dangerous.
  • Use respiratory and other personal protective equipment. If engineering and administrative controls cannot reduce hydrogen sulfide below OSHA's permissible exposure limit, employers must provide respiratory protection and other personal protective equipment (PPE), such as eye protection and possibly fire-resistant clothing. Employers must complete a PPE hazard assessment and equipment selection process in accord with the OSHA regulations before beginning any work activities. Respiratory protection should be at least:
    • For exposures below 100 ppm, use an air-purifying respirator with specialized canisters/cartridges for hydrogen sulfide. A full face respirator will provide eye protection.
    • For exposures at or above 100 ppm, use a full face pressure demand self-contained breathing apparatus (SCBA) with a minimum service life of thirty minutes or a combination full face pressure demand supplied-air respirator with an auxiliary self-contained air supply. Exposures at or above 100 ppm are considered immediately dangerous to life and health (IDLH).
    • Whenever respirators are used, the employer must have a respiratory protection program that meets the requirements of OSHA's Respiratory Protection standard (29 CFR 1910.134). This program must include proper respirator selection, fit testing, medical evaluations, and training. For more information on respiratory protection see:
    • OSHA's Respiratory Protection Safety and Health Topics Page. Provides information on what respirators are, how they work, and what is needed for a respirator to provide protection.
    • OSHA's Small Entity Compliance Guide for the Respiratory Protection Standard (PDF*). This guide is intended to help small businesses comply with the OSHA Respiratory Protection standard.
    • Refer to Other Resources for more information about controlling hydrogen sulfide exposures in specific industries and operations.

Did you enjoy this article? Click here to subscribe to ISHN.

You must login or register in order to post a comment.

Multimedia

Videos

Image Galleries

Scenes from the World of Safety

Sights, signs & symbols from the National Safety Congress & Expo held in San Diego, CA, September 15-18

11/4/14 2:00 pm EST

Eye Injuries: You rarely see them coming. Practical Solutions for reducing injuries to the eye.

The 3M Eye Injury Reduction webinar will provide an examination of how to help solve eye injuries in the workplace. This issue continues to challenge virtually every industry, and the solution is often times multifaceted. 3M will share some new tools and approaches to help you in solving this issue.

ISHN Magazine

ISHN JAN 2015 COVER

2015 January

Check out ISHN's first issue of 2015, which features articles about hearing protection as well as the State of the EHS Nation 2015 Survey.

Table Of Contents Subscribe

THE ISHN STORE

M:\General Shared\__AEC Store Katie Z\AEC Store\Images\ISHN\safetyfourth.jpg
Safety Engineering, 4th Edition

A practical, solutions-driven reference, Safety Engineering, 4th edition, has been completely revised and updated to reflect many of today’s issues in safety.

More Products

For Distributors Only - January 2015

FDO JAN 2015 COVER

 

For Distributors Only is ISHN's niche brand standard-sized magazine supplement aimed at an audience of 2,000 U.S. distributors that sell safety products. Circulation only goes to distributors. 

CHECK OUT THE JANUARY 2015 ISSUE OF FDO HERE

STAY CONNECTED

Facebook logo Twitter YouTubeLinkedIn Google + icon

ishn infographics

2012 US workplace deathsCheck out ISHN's new Infographic page! Learn more about worker safety through these interactive images. CLICK HERE to view the page.