Menhaden fish terminal facilities

Tanks used for receiving or storing bailwater must be thoroughly drained and left open to the air at the end of each day unless the bailwater has been treated to remove hydrogen sulfide-producing contaminants and that treatment’s effectiveness has been established by the employer. See 1917.73(a)(1).

• If an employer treats bailwater to remove H2S-producing contaminants, they must have evidence the treatment works before skipping daily drainage and ventilation.
• The purpose is to minimize contamination of recirculated water and to reduce buildup of hazardous gases.

Before any employee enters a dock tank, the tank must be drained, rinsed, and tested for hydrogen sulfide (H2S) and oxygen levels; entry is prohibited if H2S exceeds 20 ppm or oxygen is less than 19.5%, except in emergencies. See 1917.73(a)(2).

• Tests must check both H2S concentration and oxygen percent by volume.
• The 19.5% oxygen limit aligns with the definition of oxygen-deficient atmosphere in OSHA’s respirator standard (29 CFR 1910.134).
• For further explanation about oxygen-deficient atmospheres and when OSHA coverage applies, see OSHA’s interpretation on oxygen-deficient atmospheres in HVAC systems (2024-07-16).

Designated personnel must conduct tests using suitable test equipment and must have respiratory protective equipment that meets 1910.134. See 1917.73(a)(3).

• "Designated personnel" should be trained to use the instruments and interpret results.
• Respirators and other protective equipment used for testing must comply with OSHA’s Respiratory Protection Standard (29 CFR 1910.134).
• Keep calibration and maintenance records for gas detectors and respirators per employer procedures.

Pipelines and hoses must be completely drained after each day's operation and left open to the air. See 1917.73(b).

• This prevents trapped bailwater from producing hydrogen sulfide or other hazardous atmospheres overnight.
• Ensure drain points and hose ends are in safe, labeled locations to prevent slips, spills, or worker contact.

At least four units of respiratory protective equipment — either supplied-air respirators or self-contained breathing apparatus (SCBA) that comply with 1910.134 — must be available in a labeled cabinet for immediate emergency use. See 1917.73(c).

• These units are specifically for emergency responses to oxygen deficiency or hydrogen sulfide incidents.
• Employers should maintain inspection, cleaning, and fit/maintenance records per 29 CFR 1910.134.
• Make sure replacement cylinders and spare parts are stored nearby and ready for use.

Any employee entering a tank during an emergency must wear a lifeline and safety harness, and at least two other employees, similarly equipped and wearing respiratory protection, must be continuously stationed outside the tank to observe and perform rescue. See 1917.73(c).

• The two observers must be ready to perform immediate rescue and must have appropriate respiratory and retrieval equipment.
• Rescue procedures and the use of lifelines/harnesses should be practiced and documented as part of emergency planning.

The plant superintendent and foremen must be trained and knowledgeable about hydrogen sulfide and oxygen-deficient hazards, including proper use of respiratory and rescue equipment and rescue procedures; other supervisory personnel must be informed of the hazards and instructed in necessary safety measures. See 1917.73(d).

• Training should cover hazard recognition, gas monitoring, respirator selection and use (consistent with 29 CFR 1910.134), emergency response, and rescue roles.
• Keep training records and provide refresher training when procedures, equipment, or hazards change.

Yes, supervisory personnel must be on hand at dockside to supervise the discharging of bailwater from vessels. See 1917.73(e).

• Supervisors ensure safe practices, verify the atmosphere is tested, confirm drainage and ventilation procedures are followed, and manage emergency response if hazardous conditions develop.
• Supervisory presence also helps enforce PPE, respirator use, and rescue staffing requirements.

Routine entry into a dock tank is prohibited when hydrogen sulfide exceeds 20 parts per million (ppm) or oxygen content is below 19.5% by volume; only emergency entry is allowed outside those limits. See 1917.73(a)(2).

• The 19.5% oxygen threshold corresponds to OSHA’s definition of an oxygen-deficient atmosphere in 29 CFR 1910.134 and is discussed in OSHA’s interpretation on oxygen-deficient atmospheres (2024-07-16).
• If readings exceed limits, ventilate, purge, and retest until safe conditions are confirmed before entry.

Employers may avoid daily drainage and leaving tanks open only if the bailwater has been treated to remove hydrogen sulfide–producing contaminants and the employer has established the treatment’s effectiveness. This is the limited alternative allowed by 1917.73(a)(1).

• Any alternative must be supported by documented testing or monitoring that shows H2S production is controlled.
• Respiratory protection and atmospheric testing requirements in 1917.73(a)(3) and 29 CFR 1910.134 still apply when employees may be exposed.

The employer is responsible for ensuring designated personnel use suitable, calibrated test equipment and for providing respirators that meet 29 CFR 1910.134 when testing tanks for H2S or oxygen deficiency, as required by 1917.73(a)(3).

• Maintain calibration records and a program for instrument maintenance.
• Respirator selection, fit testing, and training must follow the procedures in 29 CFR 1910.134.

Both supplied-air respirators and self-contained breathing apparatus (SCBA) are acceptable emergency respirator options under 1917.73(c) as long as they comply with 29 CFR 1910.134. See 1917.73(c).

• Choice depends on the hazard (e.g., IDLH conditions from H2S or oxygen deficiency often require SCBA under 29 CFR 1910.134(d)(2)(iii)).
• Employers must provide training, inspection, and maintenance for whichever equipment is used, per 29 CFR 1910.134.

For planned (non-emergency) entries, 1917.73(c) requires that any entrant be supported by at least two other employees stationed outside the tank, equipped for rescue and observation; entrants must wear lifelines and harnesses for retrieval. See 1917.73(c).

• Even during planned entries, employers must ensure respiratory protection is provided per 29 CFR 1910.134 when atmospheres are hazardous or uncertain.
• Rescue personnel must be trained and ready to perform immediate retrieval.

Employees may enter a tank in an emergency even if H2S exceeds 20 ppm, but they must use appropriate respiratory protective equipment and lifelines/harnesses, and be supported by rescue personnel as required by 1917.73(c).

• Entry under emergency conditions increases risk and demands SCBA or supplied-air respirators that meet 29 CFR 1910.134 and full rescue readiness.
• Document the emergency entry, protective measures taken, and after-action review.

Employers should document validated treatment procedures and monitoring data that demonstrate removal of H2S-producing contaminants and retain records showing treatment effectiveness before they omit daily drainage, as allowed by 1917.73(a)(1).

• Keep lab results, monitoring logs, and process control records proving H2S is controlled under all foreseeable conditions.
• Re-validate treatment after process changes and maintain records for inspections.

Superintendents and foremen must be trained and knowledgeable about H2S and oxygen-deficiency hazards and the use of respiratory and rescue equipment; while 1917.73(d) does not specify exact intervals, training should be initial and repeated as needed—whenever procedures, equipment, or hazards change. See 1917.73(d) and the respiratory training requirements in 29 CFR 1910.134.

• Practical best practice: provide initial training, periodic refresher training, and retraining after incidents or equipment changes.
• Keep training records to demonstrate compliance.

Employers must designate personnel to perform tank testing; those individuals should be trained in using the instruments, interpreting readings for H2S and oxygen, and using appropriate respiratory protection per 1917.73(a)(3) and 29 CFR 1910.134.

• Designated testers need hands-on training with gas monitors, calibration skills, and familiarity with action levels (20 ppm H2S, 19.5% O2).
• Document training and competency assessments.

Yes — 1917.73(c) requires respiratory protective equipment to be available in a suitably labeled cabinet for immediate use, and it should be located where emergency responders can quickly retrieve it at the dockside or other designated emergency area. See 1917.73(c).

• Labeling should identify the cabinet as emergency respiratory equipment and list contents and inspection dates.
• Keep the cabinet secured but accessible and ensure all authorized personnel know its location.

The 19.5% oxygen cutoff in 1917.73(a)(2) specifically governs entry into dock tanks, but oxygen-deficient atmospheres are dangerous workspace-wide and must be addressed per OSHA’s Respiratory Protection Standard 29 CFR 1910.134 and related guidance (2024-07-16).

• Even outside tanks, employers should monitor confined or enclosed spaces and protect workers when oxygen may drop below 19.5%.
• Treat oxygen-deficient areas as immediately dangerous to life or health (IDLH) and provide appropriate protection.

If a dock tank has oxygen at 18% (below 19.5%), employees must not enter except in an emergency, and any entry requires appropriate respiratory protection and rescue readiness as outlined in 1917.73(a)(2) and 1917.73(c).

• Ventilate and purge the tank, then retest until oxygen rises above 19.5% before routine entry.
• If emergency entry is unavoidable, use SCBA or supplied-air respirators that comply with 29 CFR 1910.134, lifelines, harnesses, and standby rescue personnel.

Draining pipelines and hoses is required by 1917.73(b), but whether a drain point constitutes a confined space depends on the specific configuration; confined space regulations and procedures (e.g., permit-required confined spaces) may apply when entry into tanks or enclosed piping is needed. See 1917.73(b) and consult general confined space standards and site-specific assessments.

• If entry into pits, tanks, or enclosed piping is required, treat as confined-space entry: test atmosphere, provide ventilation, and follow rescue/permit procedures.
• Coordinate with employers’ confined-space programs and train personnel accordingly.

Supervisors should keep records of training (topics, dates, attendees), instrument calibration and gas testing logs, respirator maintenance and inspection sheets, and emergency drill/rescue practice records to demonstrate compliance with 1917.73(d) and respirator requirements in 29 CFR 1910.134.

• Records should show that designated testers are qualified, respirators are fit-tested and maintained, and emergency equipment (at least four units) is ready for immediate use.
• Retain records per employer retention policy and make them available for inspections.

Remote continuous monitoring can supplement but not necessarily replace the requirement that tanks be drained, rinsed, and tested before entry under 1917.73(a)(2); employers must ensure any monitoring method provides reliable, current readings and that designated personnel interpret results and take appropriate action. See 1917.73(a)(3).

• Employers should validate remote sensors, maintain calibration, and have procedures for confirming readings before entry.
• When in doubt or when sensors indicate hazardous conditions, follow ventilation and retesting procedures before allowing entry.