NORMAL OPERATIONS

During normal drilling operations, H₂S is typically first detected by odor (<1 ppm). When H₂S odor is detected, the offshore installation manager should be notified immediately. After consultation with the operations manager and scientists, the offshore installation manager determines whether invoke one of the H₂S hazard conditions.

During an H₂S hazard condition of ALERT or higher, all drilling operations are suspended until the presite H₂S preparations are completed, including H₂S safety training, which can be given to each shift before they start work.

In addition, the offshore installation manager can permit drilling operations to resume while fixed-station detectors are being installed, provided portable detectors are available for monitoring and H₂S levels do not exceed 20 ppm when measured at the drill string or core.

At a minimum, a fixed detector must be installed on the rig floor and on the core-receiving platform.

In case of an unplanned or unexpected release of H₂S gas, all personnel should

• Hold their breath if air breathing equipment is not available;
• Rapidly evacuate the area containing the H₂S and move upwind if possible;
• Move up a deck to get upwind of the source;
• If available, put on a BA;
• Evacuate anyone who may be affected by the gas to a safe area; administer resuscitation or oxygen as needed or call the ship's doctor;
• Put on air breathing equipment before helping anyone overcome by H₂S;
• Quickly evacuate to the assigned or announced safe-briefing area to receive instructions from supervisory personnel; and
• Not panic.