Emergency Procedures for H2S. Hydrogen-sulphide is one of the most vicious and deadly hazards that can be encountered while drilling and forms EXPLOSIVE mixtures with air. When drilling in an area where hydrogen-sulphide gas H2S might be encountered the rig must be equipped  to meet the and control even the smallest shows.  Even in small amounts it is dangerous to your health.  This is a poisonous gas that can paralyze your breathing system and kill within in minutes. Equipment maintenance and supervision are priority with all members of the crew being kept informed of the situation. This is not the job of the rig crew and a service company should be engaged. Constant training and drill should be organize with all supporting elements. This should include any locale community's. Contingence plans and safe areas must be well established. with wind sock in full view.  "Never", Never take a H2s operation lightly. Below you will find an introduction but It is far from finished General Notes If a given concentration of H2S should occur on a drilling rig, it is important that different procedures are made that must be followed, depending on how dangerous a situation. The personnel on the rig must know these procedures, which must be regularly exercised, they must also be familiar with the safety and emergency equipment to be used in such a situation. The following gives an example of how a plan containing safety and emergency procedures can be worked out for a off shore operation However this can be adapted to suite other types of operation. by adding to or deducting from. Although not hard and fast, it is a guide line for someone having to prepare a rig. and was used to set up a Jack up rig in 1989 The rig should be  equipped with gas detectors, especially designed for H2S, sensors should mounted at the rig floor, shale shaker, cellar deck, mud pump room, control centre, air-conditioning room. and mud logger shack When encountering H2S, the primary or initial alarm in the control centre "This could be the Toolpushers office" will tip at 20 ppm. The rig floor must be informed immediately. (1) H2S conditions Pre-alarm Crews should be notified from the drilling office and on the rig "blackboard" several days in advance before reaching the expected zone of H2S.  All personnel should remain in a ready condition to react at the sound of the gas alert. Alarm Condition I Gas concentration between 0 - 10 ppm. No warning sign or alarm is used. Control centre "could be Mud logging shack" should inform driller and drilling office. If equipment has not already been fitted personnel should check safety and air breathing equipment for correct functioning and keep equipment available.