H2S Alarm Condition III Gas concentration of 50 ppm or more is EXTREME DANGER TO LIFE. All non-essential personnel will prepare for evacuation. Note: From the time Alarm Condition III is a fact, no unauthorized personnel will be allowed to enter the shaker area, cellar deck or mud pump room. Notes and Information The acceptable concentration for 8 hours exposure to H2S is 20 ppm.  Hydrogen-sulphide is heavier than air, colourless and forms an explosive mixture with air between 4.3 and 46% by volume. One breath of 1,000 ppm concentration H2S will result in death within minutes. The "Buddy System" Whenever H2S is suspected, personnel must wear breathing apparatus before entering the contaminated area and MUST have a "back-up man" (buddy), also with breathing apparatus, available. Safe Briefing Stations The Barge Captain will indicate these on the rig "black-board". There will be two briefing stations so that one is always upwind of the drilling rig. Spare air bottles will be stored at the "safe briefing area" and bottles must only be changed at this point. The "NO SMOKING RULES" will be followed outside all living quarters as soon as "Alarm Condition 1" has been put into force. As the above introduction stated, we are drilling in a very dangerous area with a very dangerous gas. As every man on the rig at all times will have to be ready for H2S, and must be trained accordingly. The rig has to be equipped with sufficient breathing equipment for all personnel onboard. This should include the maximum of service people that could be at the rig at any one time. As the accurate function of the facemask depends on how airtight the mask seals to your face, you will be asked to remove your beard (facial hair) or assume responsibility for risk of death or serious bodily harm. Alarm Condition Killing the well with weighted mud, dumping gas cut mud through poor boy degasser and possum belly. All rig personnel will wear breathing apparatus. Non-essential personnel will leave the rig floor for "safe briefing area". Crane driver will Lay down crane not required. Pick up walkie-talkies and distribute to rig floor and Barge Captain and Toolpusher. All radios to be on stand-by Channel 13. Assist boatswain with anchor winches. Check personnel basket on upwind side. Stay in contact with rig floor for possible extra personnel. Barge Engineer will Set all anchor winches and clutches in gear and check for sufficient power to winch. Place a walkie-talkie Channel 13 at each anchor winch control house. Check with portable gas detector that upwind crane deck is free of H2S. In case of evacuation, boatswain will assist crane driver at upwind crane.