Interference with communications

Cargo handling must stop whenever the noise prevents workers from hearing or clearly understanding warnings or instructions necessary for safe operations. This is required by 1917.20, which says cargo handling shall not be carried on when such work interferes with communications of warnings or instructions.

• If workers cannot reliably hear hand signals, radios, horns, or oral directions because of the noise, operations must be suspended until communication is restored.
• Use temporary controls (e.g., quieter methods, scheduling, or alternate communication) only if they ensure warnings and instructions remain effective.

The employer is responsible for determining whether noise-producing activities interfere with communication and must stop cargo handling if interference exists. 1917.20 places the duty on employers to ensure that warnings and instructions can be communicated.

• Supervisors and safety personnel should assess conditions and take action (stop work, implement controls, or provide effective alternatives).
• Workers should report when they cannot hear critical warnings so the employer can reassess and act.

Yes — visual signals can be used as an alternative or supplement to audible warnings if they provide effective communication, but any equipment changes must comply with related equipment rules and not reduce safety. 1917.20 requires that warnings and instructions be communicable; the OSHA Letter of Interpretation about strobe lights explains that installing a strobe light in addition to an audible alarm is allowed provided any required manufacturer or engineer approvals and training needs are met (see https://www.osha.gov/laws-regs/standardinterpretations/2004-12-21-0).

• If you add visual signals, keep the audible device where required and ensure workers are trained to recognize the new signals.
• Follow any vehicle-equipment modification procedures and obtain written approval from the manufacturer or a qualified engineer when required, as explained in the strobe-light interpretation.

No — you cannot simply remove required audible warnings and rely only on visual signals unless the change still ensures effective communication and complies with equipment modification requirements. 1917.20 requires that warnings be communicable, and OSHA's strobe-light interpretation states that installing a strobe in addition to an existing alarm is permissible but modifications that affect safety may require manufacturer or professional engineer approval (https://www.osha.gov/laws-regs/standardinterpretations/2004-12-21-0).

• If removing an alarm would make warnings ineffective in some conditions (e.g., low visibility), the employer must not remove it.
• Where removal or modification is contemplated, follow the approval steps and consider operator retraining as noted in the interpretation.

Practical alternatives include using effective visual signals, upgrading or supplementing communication equipment (for example, two‑way radios with headsets), scheduling noisy work outside cargo operations, or implementing engineering controls to reduce noise — but only if the alternatives fully restore the ability to communicate warnings and instructions. 1917.20 requires that cargo handling not proceed when communication is impaired.

• Any vehicle modification (like adding strobes) that affects safety should follow the approval process described in the strobe-light interpretation (https://www.osha.gov/laws-regs/standardinterpretations/2004-12-21-0).
• Provide training so workers recognize and respond to alternate signals, and verify that the alternative works in actual conditions before resuming operations.

Section 1917.20 does not itself require written documentation of each stoppage; however, employers must ensure safety and should keep records of significant incidents, corrective actions, and training to demonstrate that they met their duty to maintain effective communications. 1917.20 sets the performance obligation to stop cargo handling when communications are impaired.

• Good practice: log the cause of the interference, the corrective steps taken, any approvals for equipment changes, and worker training provided.
• Documentation can help show due diligence in the event of an inspection or incident review.

No — hearing protection must not prevent workers from hearing warnings or instructions that are necessary for safe operations; if standard hearing protectors block critical warnings, the employer must provide alternatives that restore effective communication. 1917.20 requires that communications of warnings and instructions be maintained.

• Consider level‑dependent hearing protectors, in‑ear communication headsets, or visual signals where appropriate.
• Train workers on the use of selected hearing protection and verify that the chosen controls allow them to perceive required warnings.

The employer should schedule the noisy maintenance so it does not interfere with cargo-handling communications, or stop cargo operations during the noisy work; if neither is possible, provide and verify effective alternative communications before continuing cargo handling. 1917.20 requires suspension of cargo handling when communication is interfered with.

• Plan work sequencing to avoid overlap of noisy activities and cargo operations.
• If maintenance must occur, use certified engineering controls, approved communication alternatives, and training so that warnings remain clear.

No — Part 1917, including 1917.20, does not apply to a designated waterfront facility used solely for bulk storage, handling, and transfer of liquids or gases; OSHA explained this scope exclusion in its interpretation on applicability to waterfront facilities (https://www.osha.gov/laws-regs/standardinterpretations/2017-05-31). See Part 1917 for the marine terminal scope and definitions.

• If your operation is a designated waterfront facility as described in the interpretation, Part 1917 standards typically do not apply, though other OSHA standards or local rules might still impose communication or noise requirements.
• When in doubt, consult OSHA regional enforcement or legal counsel to confirm which standards apply.

No — an operator may not leave controls or abandon a suspended load because of noise; if noise prevents safe communication, cargo handling must be stopped until communication and safe operation can be ensured. OSHA's crane‑operator interpretation states that an operator must be physically able to perform the task without unscheduled interruption, and leaving the controls while a load is suspended can violate safety requirements (https://www.osha.gov/laws-regs/standardinterpretations/2013-09-13). Combine that duty with the communication requirement in 1917.20.

• Stop operations if the operator cannot safely control the equipment or receive necessary instructions.
• Implement communication alternatives or reduce noise so the operator can remain at the controls and safely complete lifts.

Yes — employers should provide refresher training and evaluate operators because adding visual aids or other signal changes can affect safe operation; the strobe-light interpretation says operators may need refresher training when such modifications affect safe operation (https://www.osha.gov/laws-regs/standardinterpretations/2004-12-21-0), and 1917.20 still requires that warnings be effectively communicated.

• Verify that all operators and affected workers understand and can correctly respond to the new signals before resuming normal operations.
• Keep training records showing who received the refresher and when.

No — personal music players or earbuds are not an acceptable substitute for safety-critical communication because they often mask warnings and reduce situational awareness; 1917.20 requires that warnings and instructions be conveyed clearly during cargo handling.

• If using headsets for two‑way radios, ensure they are designed for safety communication (not personal music devices) and that they allow workers to receive and acknowledge warnings.
• Implement employer‑provided communication systems and training that ensure reliable two‑way exchange of warnings and instructions.

If vessel or hold geometry causes alarm sounds to become excessively loud or creates dead zones for communication, the employer must take action to ensure warnings and instructions remain effective — for example, supplement with approved visual signals, relocate workers, reduce noise sources, or suspend cargo handling until communications are reliable. This follows the requirement in 1917.20 that cargo handling not continue when noise interferes with necessary communications.

• Any technical modification (e.g., relocating or adding alarms or strobes) should follow equipment‑modification approval procedures when applicable (see the strobe-light interpretation at https://www.osha.gov/laws-regs/standardinterpretations/2004-12-21-0).
• Confirm effectiveness with a practical test (workers responding correctly to signals) before resuming operations.

No — written procedures are not a substitute for effective real‑time warnings and instructions; 1917.20 requires that workers actually be able to receive warnings and instructions during operations. If noise prevents verbal communication, employers must provide reliable real‑time alternatives (visual signals, approved radios/headsets) and train workers to use them.

• Written procedures should complement, not replace, effective on-the-job communication methods.
• Verify through drills or observations that the real‑time alternatives work under actual noise conditions.

Yes — if intermittent or short bursts of noise make it impossible for workers to hear or understand warnings or instructions when those communications are needed, cargo handling must be suspended during those periods or alternatives must be provided that ensure warnings are received. 1917.20 focuses on whether communication is interfered with, not on the duration of the noise.

• Assess whether the bursts coincide with times when warnings or instructions are essential (e.g., during lifts or signaling sequences).
• Use procedural controls (pause operations during blasts) or technical solutions to ensure safety.