Scope: This standard provides the requirements for precautions and the order of testing before entering confined and enclosed spaces and other dangerous atmospheres.

Special Requirements: Testing/tested, PEL, inspected, competent person, determined, evaluate, inform, first aid/CPR, hazard information, emergency procedures, safety rules, monitored, warning label, rescue, respirator, PPE, practice drills, certify/certification, training, rescue teams, references other standards 

The employer shall ensure that atmospheric testing is performed in the following sequence: oxygen content, flammability, toxicity.

1915.12(a)(1) - The employer shall ensure that the following spaces are visually inspected and tested by a competent person to determine the atmosphere's oxygen content prior to initial entry into the space by an employee: [Reference paragraph (a)(1)(i) - (v)].

1915.12(a)(2) - If the space to be entered contains an oxygen deficient atmosphere, the space shall be labeled "Not Safe for Workers" or, if oxygen-enriched, "Not Safe for Workers - Not Safe for Hot Work." If an oxygen-deficient or oxygen-enriched atmosphere is found, ventilation shall be provided at volumes and flow rates sufficient to ensure that the oxygen content is maintained at or above 19.5 percent and below 22.0 percent by volume. The warning label may be removed when the oxygen content is equal to or greater than 19.5 and less than 22.0 percent by volume.

1915.12(a)(3) - An employee may not enter a space where the oxygen content, by volume, is below 19.5 percent or above 22.0 percent. Exception: An employee may enter for emergency rescue or for a short duration for installation of ventilation equipment necessary to start work in the space provided: [Reference paragraph (a)(3)(i) - (ii)].

• 1915.12(a)(3)(ii) - Respiratory protection and other appropriate personal protective equipment and clothing are provided in accordance with Subpart I - personal protective equipment, of this part.

1915.12(b)(1) - The employer shall ensure that spaces and adjacent spaces that contain or have contained combustible or flammable liquids or gases are:

• 1915.12(b)(1)(i) - Inspected visually by the competent person to determine the presence of combustible or flammable liquids; and
• 1915.12(b)(1)(ii) - Tested by a competent person prior to entry by an employee to determine the concentration of flammable vapors and gases within the space.

1915.12(b)(2) - If the concentration of flammable vapors or gases in the space to be entered is equal to or greater than 10 percent of the lower explosive limit, the space shall be labeled "Not Safe for Workers" and "Not Safe for Hot Work." Ventilation shall be provided at volumes and flow rates sufficient to ensure that the concentration of flammable vapors is maintained below 10 percent of the lower explosive limit. The warning labels may be removed when the concentration of flammable vapors is below 10 percent of the lower explosive limit.

1915.12(b)(3) - An employee may not enter a space where the concentration of flammable vapors or gases is equal to or greater than 10 percent of the lower explosive limit. Exception: An employee may enter for emergency rescue or for a short duration for installation of ventilation equipment necessary to start work in the space, provided: [Reference paragraph (b)(3)(i) - (iv)].

• 1915.12(b)(3)(iv) - Respiratory protection and other appropriate personal protective equipment and clothing are provided in accordance with Subpart I - personal protective equipment, of this part.

1915.12(c)(1) - The employer shall ensure that spaces or adjacent spaces that contain or have contained liquids, gases, or solids that are toxic, corrosive or irritant are:

• 1915.12(c)(1)(i) - Inspected visually by the competent person to determine the presence of toxic, corrosive, or irritant residue contaminants; and
• 1915.12(c)(1)(ii) - Tested by a competent person prior to initial entry by an employee to determine the air concentration of toxics, corrosives, or irritants within the space.

1915.12(c)(2) - If a space contains an air concentration of a material which exceeds a part 1915 subpart Z permissible exposure limit (PEL) or is IDLH, the space shall be labeled "Not Safe for Workers." Ventilation shall be provided at volumes and flow rates which will ensure that air concentrations are maintained within the PEL or, in the case of contaminants for which there is no established PEL, below the IDLH. The warning label may be removed when the concentration of contaminants is maintained within the PEL or below IDLH level.

1915.12(c)(3) - If a space cannot be ventilated to within the PELs or is IDLH, a Marine Chemist or CIH must re-test until the space can be certified "Enter with Restrictions" or "Safe for Workers."

1915.12(c)(4) - An employee may not enter a space whose atmosphere exceeds a PEL or is IDLH. Exception: An employee may enter for emergency rescue, or for a short duration for installation of ventilation equipment provided:

• 1915.12(c)(4)(i) - The atmosphere in the space is monitored continuously;
• 1915.12(c)(4)(ii) - Respiratory protection and other necessary and appropriate personal protective equipment and clothing are provided in accordance with Subpart I - personal protective equipment of this part.

1915.12(d) - Training of employees entering confined and enclosed spaces or other dangerous atmospheres. [Reference paragraph (d)(1) - (5)]. 

1915.12(e) - Rescue teams. The employer shall either establish a shipyard rescue team or arrange for an outside rescue team which will respond promptly to a request for rescue service. [Reference paragraph (e)(1) - (2)]. 

1915.12(f) - Exchanging hazard information between employers. Each employer whose employees work in confined and enclosed spaces or other dangerous atmospheres shall ensure that all available information on the hazards, safety rules, and emergency procedures concerning those spaces and atmospheres is exchanged with any other employer whose employees may enter the same spaces.

Scope: This standard provides the requirements for cleaning and other cold work.

Special Requirements: Testing, competent person, determine, emergency rescue, PELs, PPE, NRTL, certified, post signs, approved, references other standards

1915.13(b)(2) - Testing shall be conducted by a competent person to determine the concentration of flammable, combustible, toxic, corrosive, or irritant vapors within the space prior to the beginning of cleaning or cold work.

1915.13(b)(4) - Testing shall be conducted by the competent person as often as necessary during cleaning or cold work to assure that air concentrations are below 10 percent of the lower explosive limit and within the PELs and below IDLH levels. Factors such as, but not limited to, temperature, volatility of the residues and other existing conditions in and about the spaces are to be considered in determining the frequency of testing necessary to assure a safe atmosphere.

1915.13(b)(6) - An employee may not enter a confined or enclosed space or other dangerous atmosphere if the concentration of flammable or combustible vapors in work spaces exceeds 10 percent of the lower explosive limit. Exception: An employee may enter for emergency rescue or for a short duration for installation of ventilation equipment provided: [Reference paragraph (b)(6)(i) - (iv)]. 

• 1915.13(b)(6)(iv) - Respiratory protection, personal protective equipment, and clothing are provided in accordance with Subpart I - personal protective equipment, of this part.

1915.13(b)(7) - A competent person shall test ventilation discharge areas and other areas where discharged vapors may collect to determine if vapors discharged from the spaces being ventilated are accumulating in concentrations hazardous to employees.

1915.13(b)(9) - Only explosion-proof, self-contained portable lamps, or other electric equipment approved by a National Recognized Testing Laboratory (NRTL) for the hazardous location shall be used in spaces described in paragraph (a) of this section until such spaces have been certified as "Safe for Workers."

1915.13(b)(10 - The employer shall prominently post signs that prohibit sources of ignition within or near a space that has contained flammable or combustible liquids or gases in bulk quantities:  [Reference paragraph (b)(10)(i) - (iii)]. 

Scope: This standard provides the requirements pertaining to hot work. 

Special Requirements: Testing/tested, marine chemist, posted, authorized person, certified, certificate, labeled, warning label, competent person

1915.14(a) - Hot work requiring testing by a Marine Chemist or Coast Guard authorized person.

• 1915.14(a)(1) - The employer shall ensure that hot work is not performed in or on any of the following confined and enclosed spaces and other dangerous atmospheres, boundaries of spaces or pipelines until the work area has been tested and certified by a Marine Chemist or a U.S. Coast Guard authorized person as "Safe for Hot Work": [Reference paragraph (a)(1)(i) - (iv)].
• 1915.14(a)(2) - The certificate issued by the Marine Chemist or Coast Guard authorized person shall be posted in the immediate vicinity of the affected operations while they are in progress and kept on file for a period of at least three months from the date of the completion of the operation for which the certificate was generated.

1915.14.(b) - Hot work requiring testing by a competent person. [Reference paragraph (b)(1) - (v)].

• 1915.14(b)(2) - If the concentration of flammable vapors or gases is equal to or greater than 10 percent of the lower explosive limit in the space or an adjacent space where the hot work is to be done, then the space shall be labeled "Not Safe for Hot Work" and ventilation shall be provided at volumes and flow rates sufficient to ensure that the concentration of flammable vapors or gases is below 10 percent by volume of the lower explosive limit. The warning label may be removed when the concentration of flammable vapors and gases are below 10 percent lower explosive limit.

Scope: This standard provides the requirements for maintenance of safe conditions. 

Special Requirements: Certified, tested/tests, inspect, certificate, competent person, marine chemist, authorized person, determined, references other standards

1915.15(a) - Preventing hazardous materials from entering. Pipelines that could carry hazardous materials into spaces that have been certified “Safe for Workers” or “Safe for Hot Work” shall be disconnected, blanked off, or otherwise blocked by a positive method to prevent hazardous materials from being discharged into the space.

1915.15(b) - Alteration of existing conditions. When a change that could alter conditions within a tested confined or enclosed space or other dangerous atmosphere occurs, work in the affected space or area shall be stopped. Work may not be resumed until the affected space or area is visually inspected and retested and found to comply with §§ 1915.12 - precautions and the order of testing before entering confined and enclosed spaces and other dangerous atmospheres, 1915.13 - cleaning and other cold work, and 1915.14 - hot work, of this part, as applicable.

1915.15(c) - Tests to maintain the conditions of a Marine Chemist's or Coast Guard authorized person's certificates. A competent person shall visually inspect and test each space certified as “Safe for Workers” or “Safe for Hot Work,” as often as necessary to ensure that atmospheric conditions within that space are maintained within the conditions established by the certificate after the certificate has been issued.

1915.15(d) - Change in the conditions of a Marine Chemist's or Coast Guard authorized person's certificate. If a competent person finds that the atmospheric conditions within a certified space fail to meet the applicable requirements of§§ 1915.12 - precautions and the order of testing before entering confined and enclosed spaces and other dangerous atmospheres, 1915.13 - cleaning and other cold work, and 1915.14 - hot work, of this part, work in the certified space shall be stopped and may not be resumed until the space has been retested by a Marine Chemist or Coast Guard authorized person and a new certificate issued in accordance with § 1915.14(a) - hot work.

1915.15(e) - Tests to maintain a competent person's findings. After a competent person has conducted a visual inspection and tests required in §§ 1915.12 - precautions and the order of testing before entering confined and enclosed spaces and other dangerous atmospheres, 1915.13 - cleaning and other cold work, and 1915.14 - hot work, of this part and determined a space to be safe for an employee to enter, he or she shall continue to test and visually inspect spaces as often as necessary to ensure that the required atmospheric conditions within the tested space are maintained.”

1915.15(f) - Changes in conditions determined by competent person's findings. After the competent person has determined initially that a space is safe for an employee to enter and he or she finds subsequently that the conditions within the tested space fail to meet the requirements of §§ 1915.12 - precautions and the order of testing before entering confined and enclosed spaces and other dangerous atmospheres, 1915.13 - cleaning and other cold work, and 1915.14 - hot work, of this part, as applicable, work shall be stopped until the conditions in the tested space are corrected to comply with §§ 1915.12 - precautions and the order of testing before entering confined and enclosed spaces and other dangerous atmospheres, 1915.13 - cleaning and other cold work, and 1915.14 - hot work, as applicable.

Scope: This standard provides the requirements for warning signs and labels.

Special Requirements: Signs, label, posted, tested, certified

1915.16(a) - Employee comprehension of signs and labels. The Employer shall ensure that each sign or label posted to comply with the requirements of this subpart is presented in a manner that can be perceived and understood by all employees.

1915.16(b) - Posting of large work areas. A warning sign or label required by paragraph (a) of this section need not be posted at an individual tank, compartment or work space within a work area if the entire work area has been tested and certified: not safe for workers, not safe for hot work, and if the sign or label to this effect is posted conspicuously at each means of access to the work area.