Used with permission from PETEX®, The University of Texas, Austin. All rights reserved© PETEX 2001.

Follow OSHA requirements for confined space entry. Enter the space only if necessary and follow established procedures: Pig Launcher And Pig Receiver

See also: Permit-Required Confined Spaces in General Industry. OSHA QuickCard™. Explains what workers should do before entering a confined space, such as underground vaults, tanks, storage bins, silos or manholes based on the requirements of OSHA's Standard for Permit-required Confined Spaces [29 CFR 1910.146].

Used with permission from PETEX®, The University of Texas, Austin. All rights reserved© PETEX 2001.

Used with permission from PETEX®, The University of Texas, Austin. All rights reserved© PETEX 2001.

To protect workers from harmful hydrogen sulfide exposures:

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.

Information on general atmospheric testing methods:

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).

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.

WARNING : First responders must be trained and properly protected before entering areas with elevated levels of hydrogen sulfide.

Refer to Other Resources for more information about controlling hydrogen sulfide exposures in specific industries and operations.

NGL Recovery Occupational Safety & Health Administration