INTRODUCTION AND SCOPE Necessity. Significant amounts of produced liquid and gaseous hydrocarbons contain hydrogen sulfide in sufficient concentrations to present To successfully produce@ gather@ treat@ and transport these hydrocarbons requires that the people manning the facilities be trained and equipped to safely perform their duties. The equipment comprising the facilities must be designed to resist the harmful effects of hydrogen sulfide at anticipated operating pressures and temperatures. Operating@ surveillance@ and maintenance practices should be planned and implemented in a manner that will prevent potentially hazardous situations from developing; however@ should such a situation occur@ these practices should assure the early detection and rectification of the potentially hazardous situations. Application. Through years of experience and research effort@ the industry has developed procedures@ practices@ and guidelines that will permit the safe production@ processing@ and transportation of hydrocarbons containing hydrogen sulfide. Although attempts have been made to outline many of these guidelines@ the user must recognize that a through understanding of the particular situation and circumstances is absolutely necessary. This must be followed by careful planning@ proper selection of equipment and construction techniques@ development of operating procedures@ implementation of stringent surveillance and maintenance practices@ and frequent and intensive training of personnel. In spite of dedication to the above@ the operator must recognize the possibility of the occurrence of an emergency and develop a sound@ workable emergency response plan. Operating personnel should be regularly drilled in implementing the applicable emergency response plan (contingency plan). Production Operations. Guidelines outlined in this publication apply to oil gas producing@ gathering@ treating@ storage@ lease transportation@ well servicing and workover@ and gas processing plant operations conducted in the presence of hydrogen sulfide in concentrations that could result in an atmospheric concentration greater than 20 ppm by volume in the work area and/or that could result in a partial pressure that could be detrimental to equipment which contains the hydrocarbon bearing hydrogen sulfide. Requirements Offshore By U. S. Geological Survey. An exception to the 20 ppm criteria (refer to Paragraph 1.3) is offshore operations. The U. S. Geological Survey in their publication@ GSS-OCS-1: Safety Requirements for Drilling Operations in a Hydrogen Sulfide Environment@ imposes other requirements that would be applicable to simulataneous operations (drilling and production operations conducted on the same platform). Exploration and/or Development Drilling. With respect to production operations@ the operator will probably be aware of a potential hydrogen sulfide problem during the exploration and/or development drilling phase. This will permit early planning to properly consider the means necessary to compensate for such potential problems. Hydrogen Sulfide From Pressure Maintenance and/or waterflooding Operations. Pressure maintenance and/or waterflooding operations can result in the introduction of bacteria that cause hydrogen sulfide to develop within the producing formation in potentially harmful concentrations. Operators of such properties should be alert to this possibility and be prepared to react rapidly. Legal Requirements. This publication is presented as recommended practices and includes@ with a reasonable margin for error@ those precautions considered necessary to protect drilling and production industry workers and the public from exposure to hazardous concentrations of hydrogen sulfide. However@ many of the practices recommended are mandatory by state and Federal laws and regulations. Because of the functional and geographical diversity of these legally mandatory requirements@ no attempt has been made in these recommended practices to designate which are optional and which may be required. Furthermore@ even if all the practices recommended herein are followed@ there still may be existing or future legally imposed regulations which would not be met. In the event of any conflict between these recommended practices and legally required actions@ the requirements of law must control.