Safety and OSHA Regulations Flashcards

Under OSHA's Control of Hazardous Energy standard (29 CFR 1910.147), which scenario requires a specific WRITTEN energy control procedure rather than allowing a general procedure?

Answer: Any machine with more than one energy source or where the sequence of lockout steps must be specified to ensure employee protection

OSHA 1910.147(c)(4)(ii) requires a written energy control procedure for machines with multiple energy sources or when the means of isolation are not readily identifiable, or where the sequence of steps must be specified to protect employees. A single, general procedure is only permitted when all machines sharing that procedure have the same type/magnitude of energy, same isolation/lockout methods, and same sequence of steps.

A maintenance technician is working inside a permit-required confined space when atmospheric conditions suddenly change, triggering the gas monitor's alarm. According to OSHA 29 CFR 1910.146, what is the CORRECT sequence of actions?

Answer: The attendant orders immediate evacuation, the entrant exits without attempting to correct the hazard, and the permit is canceled before re-entry is considered

Per OSHA 1910.146(i)(6), the attendant must order immediate evacuation when conditions not allowed under the permit arise — including alarming atmospheric monitors. The entrant must exit immediately without attempting to correct the hazard. The original permit is canceled, and a new hazard assessment and permit are required before re-entry. The attendant has no obligation to consult a supervisor before ordering evacuation.

According to OSHA 29 CFR 1910.303, which of the following installations is a violation when working near live electrical parts operating at 50 volts or more?

Answer: A qualified employee working within the restricted approach boundary without appropriate arc flash PPE rated for the incident energy level

NFPA 70E and OSHA 1910.333 require that any qualified employee working within the restricted approach boundary must wear arc flash PPE appropriately rated for the calculated incident energy at that location. Using insulated tools rated at 1,000V on a 480V system is acceptable (the rating exceeds the voltage). Unqualified personnel may observe from outside the limited approach boundary. CAT III DMMs are appropriate for 208V panelboard work.

Under OSHA's Hazard Communication Standard (29 CFR 1910.1200), a Safety Data Sheet (SDS) Section 8 lists the 8-hour TWA PEL for a solvent as 100 ppm and the STEL as 150 ppm. Air monitoring shows a worker is exposed to 95 ppm averaged over the shift but hit 160 ppm for a 20-minute period. Which statement is correct?

Answer: The exposure is a violation because the STEL was exceeded during the 20-minute peak, even though the TWA is within limits

OSHA PELs include both TWA limits and Short-Term Exposure Limits (STELs). The STEL is a 15-minute average concentration that must not be exceeded at any point during the workday, regardless of whether the 8-hour TWA is within its limit. A measured exposure of 160 ppm over 20 minutes exceeds the 150 ppm STEL, making this a violation even though the TWA is compliant. STELs apply to many substances, not just carcinogens.

A facility uses a tagout-only program (no locks) for certain equipment. Under OSHA 29 CFR 1910.147, which condition MUST be documented to justify the use of tagout devices instead of lockout devices?

Answer: The employer must demonstrate that the tagout program provides a level of safety equivalent to lockout through additional measures such as removing isolating circuit elements, blocking control switches, or opening extra disconnects

OSHA 1910.147(c)(3) permits tagout-only programs ONLY when the employer can demonstrate that the tagout system will provide full employee protection equivalent to lockout. This requires demonstrating additional safety measures — such as removing fuses, blocking actuating buttons, opening additional disconnects, or removing valve handwheels — that render the energy isolation as effective as a physical lock. Simply lacking lockout hardware or posting a notice is insufficient justification.

Under OSHA's Process Safety Management standard (29 CFR 1910.119), a covered facility modifies a heat exchanger by changing its operating pressure rating by 8%. Which PSM element is PRIMARILY triggered by this change?

Answer: Management of Change (MOC), requiring a written review of technical basis, safety and health impacts, required modifications to procedures, time period for the change, and authorization before startup

OSHA 1910.119(l) — Management of Change — is triggered any time there is a change to process chemicals, technology, equipment, or facilities (other than replacements in kind). An 8% change in operating pressure rating is not a replacement in kind and requires a formal MOC review covering technical basis, safety/health impacts, documentation updates, employee training requirements, and authorization before the change is put into service. PSSR may also be required before startup, but MOC is the primary element triggered by the change itself.