Cleaning and cold work requirements

Spaces that contain or last contained bulk quantities of flammable/combustible liquids or gases, or bulk quantities of toxic, corrosive, or irritating liquids, gases, or solids are covered by this rule. The rule lists these locations in 1915.13(a), specifically 1915.13(a)(1) and 1915.13(a)(2).

Liquid residues must be removed from work spaces as thoroughly as practicable before employees start cleaning or cold work. 1915.13(b)(1) requires special care to avoid spilling or draining hazardous liquids into surrounding water or onto the shore-side work area.

• "As thoroughly as practicable" means taking reasonable steps to remove visible liquid and minimize lingering hazardous residues before entry or work begins.
• Employers should plan containment and cleanup so residues are not simply displaced into the environment while preparing the space for work.

A competent person must perform testing to determine air concentrations of flammable, combustible, toxic, corrosive, or irritant vapors before cleaning or cold work begins. 1915.13(b)(2) requires this, and OSHA's interpretation explains that a competent person is expected to recognize and evaluate hazardous atmospheres and specify needed protection; see OSHA's letter on competent person requirements in shipyards at https://www.osha.gov/laws-regs/standardinterpretations/2016-04-18.

• Employers must ensure the competent person has the training and authority to test atmospheres and decide controls.

Ventilation must keep flammable vapor concentrations below 10 percent of the lower explosive limit (LEL). 1915.13(b)(3)(i) states that continuous ventilation be provided at volumes and flow rates sufficient to maintain that level.

• The rule also notes that highly volatile residues may require additional ventilation to maintain concentrations below 10% LEL and within any applicable permissible exposure limits.

Ventilation must keep toxic, corrosive, or irritant vapors within OSHA permissible exposure limits (PELs) and below IDLH (immediately dangerous to life or health) levels. 1915.13(b)(3)(ii) requires continuous ventilation at rates sufficient to meet those exposure criteria.

• If the chemical has no OSHA PEL, use a competent person to evaluate the hazard and select appropriate controls (see OSHA's competent person interpretation at https://www.osha.gov/laws-regs/standardinterpretations/2016-04-18).

Testing must be conducted by the competent person as often as necessary during the operation to assure air concentrations remain below 10% LEL, within PELs, and below IDLH levels. 1915.13(b)(4) requires this continuous oversight.

• Factors to determine frequency include temperature, residue volatility, and other conditions in and around the space, as noted in the same paragraph.
• Employers should consult the appendix referenced in the standard for additional guidance on testing frequency.

Spills or other releases of flammable, combustible, toxic, corrosive, and irritant materials must be cleaned up as work progresses. 1915.13(b)(5) requires prompt cleanup rather than postponing until after other tasks are complete.

• Cleanup should be done in a way that prevents spreading contamination to surrounding water or work areas and that maintains safe atmospheric conditions for workers.

Employees may not enter a confined or enclosed space if flammable or combustible vapors exceed 10 percent of the LEL. 1915.13(b)(6) plainly prohibits entry above that threshold.

• Exception: short-duration entry for emergency rescue or to install ventilation is allowed only if the conditions in 1915.13(b)(6)(i)-(iv) are met (no ignition sources, continuous monitoring, atmosphere maintained above UEL, and appropriate respiratory and protective equipment provided).

Short-duration entry for emergency rescue or to install ventilation is allowed only if no ignition sources are present; the atmosphere is continuously monitored; the atmosphere is maintained above the upper explosive limit (UEL); and respiratory protection and other PPE are provided in accordance with Subpart I. These requirements are found in 1915.13(b)(6)(i)-(iv).

• Continuous monitoring is required during the entry to ensure conditions do not change.
• "Respiratory protection and personal protective equipment" must meet the requirements of Subpart I of Part 1915.

A competent person must test ventilation discharge areas and other locations where discharged vapors might collect to determine whether vapors are accumulating at hazardous concentrations. 1915.13(b)(7) requires this testing.

• The goal is to catch vapor build-up outside the ventilated space that could create hazards for workers in adjacent or downwind areas.

If tests show that exhaust vapors are accumulating in hazardous concentrations in discharge or adjacent areas, all work in the contaminated area must stop until the vapors have dissipated or been removed. 1915.13(b)(8) requires stopping work in that area.

• Employers should ventilate and retest the area, evacuate affected workers, and not resume work until testing confirms safe conditions.

Only explosion-proof, self-contained portable lamps or other electric equipment approved by a Nationally Recognized Testing Laboratory (NRTL) for the hazardous location may be used until the space is certified "Safe for Workers." 1915.13(b)(9) sets this requirement.

• The note further clarifies that battery-fed portable lamps or other electric equipment bearing appropriate NRTL approval for the class/division of the location are acceptable.

The employer must prominently post signs prohibiting ignition sources at the entrance to the space, in adjacent spaces, and in the open area adjacent to those spaces. This is required by 1915.13(b)(10).

• The three specific locations are listed in 1915.13(b)(10)(i)-(iii).

All air-moving equipment and components capable of generating a static electric discharge must be electrically bonded to the vessel structure or, for land-side spaces, grounded to prevent an electric discharge in the space. 1915.13(b)(11) requires bonding/grounding.

• This includes ductwork and any parts that could build up static charge and create an ignition source when handling flammable vapors.

Yes; a competent person may recognize and evaluate exposures without an OSHA PEL and specify the necessary protections. 1915.13(b)(2) requires testing by a competent person, and OSHA's interpretation on competent person requirements explains that the competent person must be able to specify protections even when no PEL exists: https://www.osha.gov/laws-regs/standardinterpretations/2016-04-18.

• Employers must ensure the competent person has sufficient training and authority to select appropriate controls and PPE.

When residues are highly volatile and additional ventilation may be required to keep flammable vapors below 10% LEL, employers must provide the extra ventilation and testing needed to maintain safety. The note to 1915.13(b)(3)(i) explicitly calls out highly volatile residues as requiring additional ventilation.

• If adequate ventilation cannot be achieved, do not allow workers to enter until the atmosphere is safe or appropriate protective measures (per Subpart I) are in place.

The employer is responsible for ensuring testing and safety measures are performed by a competent person and that the conditions of 1915.13(b) are met before employees perform cleaning or cold work. The standard repeatedly places duties on the employer to make sure atmospheres are tested, ventilated, and monitored.

• OSHA's interpretation of "competent person" explains that the responsibilities placed upon the competent person are deemed responsibilities of the employer and that the competent person must be capable of specifying necessary protections: https://www.osha.gov/laws-regs/standardinterpretations/2016-04-18.

Respiratory protection and other personal protective equipment must be provided in accordance with Subpart I when the exception in 1915.13(b)(6)(iv) is used for emergency or short-duration entry. Employers must follow Subpart I requirements for respirator selection, fit testing, and program administration.

• Use Subpart I provisions in Part 1915 (see the Part 1915 index at https://www.osha.gov/laws-regs/regulations/standardnumber/1915) to determine specific respiratory protection obligations.

Employers must take special care to prevent hazardous materials from spilling or draining into the water surrounding the vessel while removing liquid residues and cleaning as work progresses. 1915.13(b)(1) and 1915.13(b)(5) require this protection.

• Practical measures include containment booms, absorbent materials, drainage controls, and planning cleanup methods that capture residues rather than discharging them.

A competent person should consider temperature, volatility of the residues, and other existing conditions in and about the spaces when deciding testing frequency. 1915.13(b)(4) specifies these factors and directs testing as often as necessary.

• Appendix A to the standard provides additional information on test frequency; employers should use it along with on‑site judgment and monitoring trends to set testing intervals.

Yes; battery-fed portable lamps that bear approval from a Nationally Recognized Testing Laboratory (NRTL) for the class and division of the hazardous location are deemed to meet the requirement of 1915.13(b)(9).

• Employers must confirm the lamp's NRTL approval covers the specific hazardous classification where it will be used.

A space is considered "Safe for Workers" after a competent person has tested the atmosphere and determined it meets the limits in 1915.13(b) (e.g., flammable vapors below 10% LEL and toxic vapors within PELs and below IDLH). The competent person conducts the testing required by 1915.13(b)(2) and (4) and can declare the space safe based on those measurements.

• Employers should document the results and the identity of the competent person who certified the space as safe.

If testing shows vapors discharged from the ventilated space are accumulating to hazardous levels in adjacent areas, stop work in the contaminated area until the vapors dissipate or are removed. 1915.13(b)(7)-(8) require testing of discharge areas and halting work when hazardous concentrations are present.

• Actions include shutting down operations, increasing or redirecting ventilation, evacuating affected workers, and re-testing until safe concentrations are confirmed.