Notes: BA = fixed or portable self-contained breathing system. NA = not applicable.

The most common H₂S sources (see "Appendix B") on the JOIDES Resolution are

• Gases diffusing from recovered core and samples taken from the core;
• Gases that have accumulated in the core barrel and escape when the core catcher and/or the core liner is removed;
• Gases that are "swabbed" up the drill string when a core, downhole tool, or logging tool is recovered and escape when the drill string is opened at the rig floor;
• Gases that escape from downhole or logging tools when opened in the laboratory after use;
• Gases displaced when the inner core barrel is washed out;
• Decomposition of recovered H₂S clathrates; and
• Well blowout that releases gases up through the drill string or into the surrounding waters.

In all these cases (except for clathrates and blowout situations), the source of H₂S is small in volume or must pass through a small opening first (i.e., the open end of the drill string) before reaching a work area.

Fixed-Area Detection Stations

Fixed-area detection stations are mounted around the ship (see "Appendix A") where H₂S sources are present or in areas where H₂S may accumulate. One or two sensors can be attached to each detection station. The stations are mounted in open areas and continuously monitor for H₂S in the work area atmosphere. The detection stations are connected via radio to an alarm control panel mounted on the ship's bridge. In addition, each station may have either an audio or a visual alarm, or both.

All fixed H₂S sensors are set to detect a minimum of 10 ppm. Warning lights and horn units are installed on each detector station. If H₂S is present at concentrations at or above 10 ppm, a local audible and visual alarm will sound in the hazardous area where H₂S is detected. At the same time, an audible and visual alarm will be triggered on the central alarm panel on the bridge.

For detailed operating instructions and specifications, see the manufacturer's operator manual.

Portable Detectors

The staff on the rig floor and core-receiving platform use handheld portable detectors to spot check for the presence of H₂S. In addition, this style of detector can be used to monitor the work atmosphere.

Personal Detectors

Staff wear personal detectors while working directly with potential H₂S sources.

To determine the level of the H₂S hazard (see "Appendix C"), it is important to remember the following facts:

• H₂S concentrations will diminish with distance from the source.
• Moving air will greatly reduce the concentration of H₂S with distance from the source.
• Moving air can direct H₂S away from the sensor.
• H₂S is denser than air and will accumulate in unventilated rooms or in low areas on the ship (e.g., in the elevator well).

The following examples demonstrate why it is important to understand where and how H₂S was detected before assigning a hazard classification.

• H₂S has been swabbed up the drill pipe and released onto the drill floor when the pipe was opened to retrieve a core barrel. A fixed detector, mounted 20 ft away and downwind from the open drill pipe, measures an H₂S level of 4 ppm (no alarm).
• On the core-receiving platform, a marine specialist measures 100 ppm of H₂S using a portable detector with the sampling tube inside the cut end of the core liner.
• The alarm of the H₂S station monitoring the refrigerated core storage has gone off.

In the first example, the H₂S level measured at the detector has been reduced by distance. It is possible that the concentration of H₂S near the open drill string is at a lethal level. In an open-air location, a fixed detector cannot be used as the primary means of H₂S detection. However, the detection of any H₂S by a fixed detector in an open-air location could indicate a very serious condition near the source. When a fixed detector is activated in an open-air setting, personnel not wearing a portable breathing apparatus (BA) must leave the work area immediately until the source has been discovered (using a portable detector) and the concentration of H₂S has dropped to a safe level.

In the second example, the H₂S measurement was taken directly at the source in a confined space. Because the staff working on the core-receiving platform are in an open-air environment, a measurement should be taken 12 in away from the core to determine the actual hazard level. If this measurement shows an H₂S level >20 ppm, then BAs are only needed for individuals working directly over the core; other individuals working on the core-receiving platform do not need to wear a BA.

The third example is a serious situation because the detector is monitoring a confined space. Only individuals wearing BAs should enter this area to begin ventilation. Note, however, that H₂S readings taken in a confined space should not necessarily be used to determine H₂S hazard conditions for the entire ship.

Offshore Installation Manager

• Understands the H₂S guidelines and policies set forth in this document and ensures that all personnel aboard the JOIDES Resolution observe the same;
• Informs the operations manager, ship's master, and shipboard supervisors of the current H₂S hazard condition;
• May modify the policies in this document to fit the safety requirements of the situation; and
• Is qualified to conduct the shipboard H₂S safety training.

Night Tool Pusher

• Assists in carrying out the offshore installation manager's responsibilities listed above and
• Is qualified to conduct the shipboard H₂S safety training.

ODP Operations Manager

• Assists the offshore installation manager in enforcing the policies set forth in this document;
• Keeps ODP shipboard staff informed of the H₂S hazard situation;
• Keeps ODP onshore management informed of H₂S hazard situation; and
• Is qualified to conduct the shipboard H₂S safety training.

Ship's Master and Officers

When an H₂S emergency (>50 ppm) condition is encountered, the ship's master or ship's officer on duty is solely responsible for determining what action is required and, as necessary, sounding the general alarm to notify personnel to report to the designated safe-briefing area.

The ship's master or officer

• Designates the safe-briefing areas;
• Keeps all personnel advised of the current safe-briefing area;
• Notifies vessels and aircraft in the area of an H₂S emergency;
• Maintains both fixed and portable breathing systems in a safe and working order; and
• Maintains a 24-hr watch on the bridge to monitor the H₂S central alarm panel.

Laboratory Officer

• Is qualified to conduct the shipboard H₂S safety training;
• Provides H₂S training to the science party;
• Oversees technical staff in setting up, calibrating, and testing the H₂S detector systems;
• Posts H₂S warning signs;
• Assigns the H₂S safety technician's duties;
• Ensures that the scientific party has personal protection equipment (PPE) and knows how to use it;
• Documents all training and maintains training records; and
• Assists the offshore installation manager in enforcing the policies set forth in this document.

Assistant Laboratory Officer

• Is qualified to conduct the shipboard H₂S safety training and
• Assists the laboratory officer in carrying out his responsibilities as listed above.

Ship's Department Supervisor

• Keeps staff (including the consultant and subcontractors) informed of the current H₂S hazard and
• Provides appropriate PPE and ensure that staff know how to use it.

Core Technician

• Monitors H₂S levels on the rig floor;
• Knows and executes the H₂S monitoring policies set forth in this document; and
• Keeps the offshore installation manager, operations manager, and H₂S safety technician advised of the H₂S situation in their work area.

H₂S Safety Technician

• Monitors H₂S levels on the core-receiving platform and in the core laboratory;
• Knows and executes the H₂S monitoring policies set forth in this document; and
• Keeps the offshore installation manager, operations manager, laboratory officer, and assistant laboratory officer advised of the H₂S situation in their work area.

Ship's Physician

• Confirms that personnel working in the hazardous areas do not have punctured eardrums;
• Ensures that the ship is stocked with any special medical supplies that may be needed for treating personnel exposed to H₂S; and
• Assists with training in resuscitation and H₂S first aid.

All Personnel

All personnel working in the designated hazardous areas (rig floor, core-receiving platform, core laboratory, and reefer) must

• Be familiar with the procedures outlined in this document;
• Complete an H₂S safety training course;
• Be responsible for their PPE and that it is properly stored and easily accessible;
• Be familiar with the location of all safety equipment in their work area and be able to use it upon notice;
• Stay informed of the current H₂S hazard condition; and
• Follow instructions set forth in this document or as provided by their supervisor.