Att 08 - Fire Prevention During Welding Cutting and Other Hot Work_042525 (1).pdf

NIST S 7401.04 Ver. 3 (Uncontrolled Copy in Print) Page 1 of 19

FIRE PREVENTION DURING WELDING, 1

CUTTING, AND OTHER HOT WORK 2

NIST S 7401.04 4

Document Date: 04/25/2025 5 Effective Date:1 04/01/2020 6

1. PURPOSE 9

The purpose of this suborder is to establish the requirements and associated roles and 10 responsibilities for performing activities involving hot work in NIST spaces. 11

2. BACKGROUND 14

a. NIST Policy (P) 7400.00 articulates NIST’s commitment to making fire and life safety an 15 integral core value and vital part of the NIST culture, in part by complying with applicable 16 laws, regulations, and other promulgated fire and life safety requirements. 17

b. The content of this suborder was derived primarily from Chapter 35 of the International Fire 19 Code (IFC) and the National Fire Protection Association (NFPA) Standard for Fire 20 Prevention During Welding, Cutting, and Other Hot Works (NFPA 51B). 21

3. APPLICABILITY 24

a. The provisions of this suborder apply to all hot work activities performed in NIST spaces 25 with the following exceptions: 26

(1) NIST activities involving cooking operations; 28

(2) NIST activities in laboratories or laboratory-owned shops involving candles2, Bunsen 30 burners, alcohol burners, small hand-held torches, heat or temperature baths, hot plates, 31 furnaces, ovens, small benchtop grinding wheels, or electric soldering irons; 32

(a) This exception does not apply when such activities generate slag or more than 34 incidental amounts of sparks; and 35

1 For revision history, see Appendix A.

2 The use of candles on NIST campuses is prohibited unless related to a laboratory experiment.

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(3) NIST activities in laboratories and laboratory-owned shops where welding does not 36 generate sparks or slag (or generates no more than incidental amounts of sparks) in open 37 air, e.g., enclosed orbital tube welder, small electrical (electric resistance) or water-based 38 spot welders. 39

(4) Laboratory-related fire and combustion experiments conducted in the National Fire 41 Research Laboratory. 42

4. REFERENCES 45

a. 29 CFR 1910, Subpart Q, Welding, Cutting, and Brazing 46

b. 29 CFR 1926, Subpart F, Fire Protection and Prevention 48

c. International Fire Code (IFC), Chapter 33- Fire Safety During Construction and Demolition, 50

d. IFC, Chapter 35-Welding and Other Hot Work 52

e. NFPA 51B, Fire Prevention During Welding, Cutting, and Other Hot Work 54

f. NFPA 241, Standard for Safeguarding Construction, Alteration, and Demolition Operations, 56

g. ANSI Z49.1, Safety in Welding, Cutting, and Allied Processes 58

h. NCNR-3.7, Policy on Work Requiring a Cutting and Welding Permit 60

5. APPLICABLE NIST DIRECTIVES 63

a. NIST P 7400.00: Fire and Life Safety 64

b. NIST O 7401.00: Fire and Life Safety 66

c. NIST S 7401.03: Impairment of Fire Protection and Life Safety Systems 68

d. NIST S 7101.20: Work and Worker Authorization Based on Hazard Reviews (“Hazard 70

Review”) 71

e. NIST S 7101.21: Personal Protective Equipment (PPE) 73

f. NIST S 7101.23: Safety Education and Training 75 https://www.ecfr.gov/cgi-bin/text-idx?SID=610423d8fbdc264d9183d405a918f058&mc=true&node=pt29.5.1910&rgn=div5#sp29.5.1910.q https://www.ecfr.gov/cgi-bin/text-idx?SID=610423d8fbdc264d9183d405a918f058&mc=true&node=pt29.8.1926&rgn=div5#sp29.8.1926.f https://inet.nist.gov/oshe/directives/fire-life-safety https://inet.nist.gov/oshe/directives/fire-life-safety-0 https://www.nist.gov/oshe/safety-programs/impairment-fire-protection-and-life-safety-systems-program https://www.nist.gov/oshe/safety-programs/work-and-worker-authorization-based-hazard-reviews-hazard-review https://www.nist.gov/oshe/safety-programs/work-and-worker-authorization-based-hazard-reviews-hazard-review https://www.nist.gov/oshe/safety-programs/personal-protective-equipment-ppe https://www.nist.gov/oshe/safety-programs/safety-education-and-training-set-program

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g. NIST S 7101.61: Compressed Gas Safety 76

h. NIST S 7101.73: Out of Service (OOS) 78

6. REQUIREMENTS 81

a. Authorization of Work and Workers Performing Hot Work 82

(1) Hot work in NIST spaces shall be performed only in designated areas and permit-84 required areas approved for the hot work by a NIST Permit Authorizing Individual (PAI). 85

(2) For hot work to be performed by NIST employees and covered associates: 87

(a) The requirements established by the PAI in designated area certificates and hot work 89 permits (for permit-required areas) shall be incorporated by the OU into the hazard 90 review or job hazard analysis for the hot work; and 91

(b) The activity involving the hot work and those performing it shall be authorized by the 93

OU in accordance with the requirements of this suborder and NIST S 7101.20. 94

(3) For hot work to be performed by non-R&D contractors in NIST spaces, the requirements 96 established by the PAI in a designated area certificate or hot work permit shall be 97 incorporated by the Contracting Officer’s Representative (COR) into the non-R&D 98 contractor’s safety plan. 99

(4) The following additional requirements shall be incorporated into the hazard reviews of 101 activities involving hot work performed by NIST employees and covered associates, or 102 into the safety plans for hot work performed by non-R&D contractors, whichever is 103 applicable: 104

(a) Hot work equipment shall be inspected per manufacturer’s instructions by those 106 performing the hot work each time prior to use to ensure that it is in safe operating 107 condition. 108

i. Equipment with broken, loose, or missing components, which prohibit safe 110 operation of the equipment, shall be placed out-of-service (refer to NIST S 111 7101.73). 112 https://www.nist.gov/oshe/safety-programs/compressed-gas-safety-program https://www.nist.gov/oshe/safety-programs/out-service-oos

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(b) Those performing the hot work and nearby personnel shall be suitably protected 116 against dangers such as heat, sparks, slag, and fumes in accordance with the 117 requirements of NIST S 7101.21 and 29 CFR 1910.252(b). 118

b. NIST Permit Authorizing Individuals3 120

(1) Designated areas and permit-required areas related to research activities in NIST spaces 122

(where a hazard review is required) shall be approved by an Office of Safety, Health, and 123 Environment (OSHE) PAI. 124

(2) Designated areas and permit-required areas related to construction and maintenance 126 activities in NIST spaces shall be approved by an Office of Facilities and Property 127 Management (OFPM) PAI in Boulder and by an OSHE PAI in Gaithersburg. 128

(3) Designated areas and permit-required areas related to laboratory activities not requiring a 130 hazard review can be approved by PAIs from any of the above-mentioned organizations. 131

(4) The NIST AHJ may approve the assignment of PAIs outside of the above-mentioned 133 organizations (i.e., within a laboratory OU), where special circumstances exist. 134

c. Process to Obtain a Designated Area Certificate 136

(1) For hot work to be performed by NIST employees or covered associates, a NIST 138 employee from the OU owning the proposed designated area shall submit a request using 139 the Safety Permit Application (SPA) to request an inspection of the area. 140

(2) For hot work to be performed by non-R&D contractors in NIST spaces, the COR shall 142 submit a request using SPA to request an inspection of the proposed designated area. 143

(3) A designated area certificate (please see Appendix B) shall be issued by the PAI after 145 inspection of the area and a determination that the requirements for a designated area 146 (please see Appendix C) have been met. 147

(a) The PAI shall complete an inspection of the designated area within five (5) business 149 days of the request. 150

i. Requests requiring urgency will be expedited by the PAI. 152

3 An individual must complete the PAI training module to be an approved PAI as indicated in Section 9.f.

https://www.ecfr.gov/cgi-bin/text-idx?SID=610423d8fbdc264d9183d405a918f058&mc=true&node=pt29.5.1910&rgn=div5#se29.5.1910_1252

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(4) The designated area certificate shall be prominently displayed immediately outside of the 155 designated area. 156

(5) A designated area certificate shall be valid for 1 (one) year. 158

(6) For reissuance of a designated area certificate for hot work to be performed by NIST 160 employees or covered associates, an employee from the OU owning the designated area 161 shall contact the PAI no later than one (1) month prior to the expiration date of the 162 current designated area certificate to request a re-inspection of the area. 163

(7) For reissuance of a designated area certificate for hot work to be performed by non-R&D 165 contractors, the COR shall contact the PAI no later than one (1) month prior to the 166 expiration date of the current designated area certificate to request a re-inspection of the 167 area. 168

(a) After re-inspection of the area and a determination that the requirements for a 170 designated area (please see Appendix C) continue to be met, the PAI shall issue a new 171 designated area certificate with a new issuance and expiration date. 172

d. Process to Obtain a Hot Work Permit (for Permit-Required Areas) 174

(1) For hot work to be performed by NIST employees or covered associates, a NIST 176 employee from the OU owning the proposed permit-required area shall submit a request 177 using SPA to request an inspection of the area. 178

(2) For hot work to be performed by non-R&D contractors in NIST spaces, the COR shall 180 submit a request using SPA to request an inspection of the proposed permit-required area. 181

(3) A hot work permit (please see Appendix D) shall be issued by the PAI after inspection of 183 the area and a determination that the applicable requirements for a permit-required area 184 have been met. 185

(a) The PAI shall complete an inspection of the permit-required area within two (2) 187 business days of the request. 188

i. Requests requiring urgency will be expedited by the PAI. 190

(3) The hot work permit shall be prominently displayed in the work area during the period of 192 authorized work performance (e.g., issuance to expiration). 193

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(4) The PAI shall determine the length of time for which hot work permits are valid, but the 196 time period shall be no longer than seven (7) calendar days. 197

(a) If a hot work permit is going to be needed for longer than seven (7) calendar days, the 199

PAI should consider the establishment of a designated area. 200

(b) If the area cannot be designated as a designated area, a new hot work permit must be 202 issued every seven (7) calendar days for the duration of the hot work. 203

e. Training 205

(1) Training shall be provided, documented, and recorded in accordance with the 207 requirements of the NIST S 7101.23. 208

(2) NIST employees and covered associates who are to perform hot work shall complete: 210

(a) Training provided by OSHE on this program; 212

(b) Activity-specific training, provided by the Organizational Unit (OU), required by 214 applicable hazard reviews; and 215

(c) Training provided, arranged, or approved by OSHE on the use of fire extinguishers 217

(refresher training required annually for continuance of activity). 218

(3) Official first-level supervisors of NIST employees and covered associates who are to 220 perform hot work shall complete the training provided by OSHE on this program. 221

(4) CORs for non-R&D contractors who are to perform hot work shall complete the training 223 provided by OSHE on this program. 224

(5) PAIs shall complete the PAI training module provided by OSHE on NFPA 51B and on 226 this suborder. 227

(6) NIST employees assigned to conduct fire watches shall complete: 229

(a) Training provided by OSHE on this program; and 231

(b) Annual training provided or approved by OSHE on the use of required fire 233 extinguishers. 234

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7. DEFINITIONS 236

Definitions common to all NIST Fire and Life Safety suborders are delineated in NIST O 237

7401.00. The definitions specific to this suborder are as follows. 238

a. Authority Having Jurisdiction (AHJ) – A qualified FPE4 in OSHE designated by the NIST 240 CSO to enforce5 the NIST-adopted codes and standards relevant to fire, electrical, and life 241 safety on NIST-owned and operated sites. 242

b. Designated Area – A specific area, such as a welding shop or a soldering station, in which 244 hot work is regularly performed and which has been approved for such work by a PAI based 245 on their inspection of the area against the requirements of Appendix C. 246

c. Designated Area Certificate – A document issued by a PAI pursuant to approving a location 248 for the regular performance of hot work activities for a maximum of 1 year (please see 249 Appendix C). 250

d. Fire Resistive – Refers to properties or designs to resist the effects of any fire to which a 252 material or structure can be expected to be subjected (extracted from NFPA Glossary of 253 Terms). 254

e. Fire Watch – The assignment of a person (or persons) to an area for the express purpose of 256 notifying the fire department, the building occupants, or both of an emergency; preventing a 257 fire from occurring; extinguishing small fires; or protecting the public from fire or life safety 258 changes. 259

f. Hot Work – Work involving welding, brazing, open flame soldering, heat treating, grinding, 261 thawing pipes, powder-driven fasteners, hot riveting, torch-applied roofing, or any other 262 process requiring use of a spark, flame, or heat that is capable of initiating fires or 263 explosions. 264

g. Hot Work Equipment – Electric or gas welding, cutting, and heating equipment used for hot 266 work. 267

h. Hot Work Permit – A document issued by a PAI pursuant to approving a permit-required 269 area. 270

4 See requirements for Office of Personnel Management Fire Protection Engineering Series 0804.

5 Nature of enforcement is dependent upon the severity of the violation, e.g., stop work, revoke permit, denial of use and occupancy, etc.

https://www.opm.gov/policy-data-oversight/classification-qualifications/general-schedule-qualification-standards/0800/fire-protection-engineering-series-0804/

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i. NIST Space – A space that is owned, operated, and under the control of NIST. 271

j. Noncombustible – A material that, in the form in which it is used and under conditions 273 anticipated, will not ignite, burn, support combustion, or release flammable vapors when 274 subjected to fire or heat. Materials that are reported as passing ASTM E136 shall be 275 considered noncombustible materials (extracted from NFPA Glossary of Terms). 276

k. Non-R&D Contractor – A NIST associate who performs non-R&D work at a NIST 278 workplace in accordance with the safety requirements of a contract or other legal 279 arrangement, such as a Memorandum of Understanding, with NIST Non-R&D contractors 280 include, but are not limited to, construction contractors; facilities contractors; equipment 281 installation, service, and maintenance contractors; Health Unit contractors; contract cafeteria 282 workers; and janitorial contractors. 283

l. Official First-Level Supervisor (of Another Employee or of a Covered Associate) – The 285

Rating Official on the performance plan of another employee or the supervisor of a covered 286 associate. 287

m. Permit Authorizing Individual (PAI) – An individual authorized to approve hot work requests 289 by virtue of completing the training provided by OSHE on NFPA 51B and this suborder 290

n. Permit-Required Area – Any location other than a designated area that has been approved for 292 hot work by a PAI based on their inspection of the area against the requirements of Appendix 293 C. 294

o. Welding Blanket – A heat–resistant fabric designed to be placed in the vicinity of hot work 296 operations. Intended for use in horizontal applications with light to moderate exposures such 297 as that resulting from chipping, grinding, heat treating, sand blasting, and light horizontal 298 welding. Designed to protect machinery and prevent ignition of combustibles such as wood 299 located on the underside of the blanket. (Extracted from NFPA Glossary of Terms) 300

p. Welding Curtain – A heat–resistant fabric designed to be placed in the vicinity of hot work 302 operations. Intended for use in vertical applications with light to moderate exposures such as 303 that resulting from chipping, grinding, heat treating, sand blasting, and light horizontal 304 welding. Designed to prevent sparks from escaping the area. (Extracted from NFPA Glossary 305 of Terms) 306

q. Welding Pads – A heat–resistant fabric designed to be placed directly under a hot work 308 operation such as welding or cutting. Intended for use in horizontal applications with severe 309 exposures such as that resulting from molten substances or heavy horizontal welding. 310

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Designed to prevent ignition of combustibles that are located to the underside of the pad. 311 (Extracted from NFPA Glossary of Terms) 312

8. ACRONYMS 315

a. AHJ – Authority Having Jurisdiction 316

b. ANSI – American National Standards Institute 318

c. CFR – Code of Federal Regulations 320

d. COR – Contracting Officers Representative 322

e. CSO – Chief Safety Officer 324

f. FPG – Fire Protection Group, Emergency Services Office 326

g. NFPA – National Fire Protection Association 328

h. OFPM – Office of Facilities and Property Management 330

i. OSHA – Occupational Safety and Health Administration 332

j. OSHE – Office of Safety, Health, and Environment 334

k. OU – Organizational Unit 336

l. PAI – Permit Authorizing Individual 338

m. SPA – Safety Permit Application 340

9. RESPONSIBILITIES 343

Roles and responsibilities common to all NIST Fire and Life Safety suborders are delineated in 344 NIST O 7401.00. The roles and responsibilities specific to this suborder are as follows: 345

a. OU Directors are responsible for ensuring OU activities involving hot work and those 347 conducting that work are authorized in accordance with the requirements of this suborder and 348

NIST S 7101.20. 349

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b. Official First-Level Supervisors of NIST Employees and Covered Associates Performing Hot 351 Work are responsible for: 352

(1) Ensuring the requirements established by PAIs in designated area certificates and hot 354 work permits are incorporated into the hazard reviews of the activities involving hot 355 work; 356

(2) Ensuring the requirements of Section 6.a(4) are incorporated into the hazard reviews of 358 activities involving hot work; 359

(3) Ensuring the training specified in Section 6.e is completed prior to NIST employees and 361 covered associates engaging in hot work; 362

(4) Completing the training required by Section 6.c; 364

(5) Ensuring designated area certificates are prominently displayed immediately outside the 366 designated area; and 367

(6) Ensuring hot work permits are prominently displayed in the work area during the period 369 of authorized work performance. 370

c. NIST Employees and Covered Associates Performing Hot Work are responsible for: 372

(1) Completing the training specified in Section 6.e; and 374

(2) Ensuring the requirements established by PAIs in designated area certificates and hot 376 work permits are followed. 377

d. CORs are responsible for: 379

(1) Completing the training specified in Section 6.e; 381

(2) Submitting requests for designated areas and permit-required areas using SPA; 383

(3) Ensuring the requirements established by the PAI in designated area certificates or hot 385 work permits are incorporated into the non-R&D contractor safety plans; 386

(4) Ensuring non-R&D contractors are aware of the hazards in the area where hot work will 388 be performed; 389

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(5) Ensuring non-R&D contractors are qualified to do the hot work; and 391

(6) Ensuring non-R&D contractors comply with the requirements of hot work permits and 393 their safety plans. 394

e. NIST AHJ is responsible for: 396

(1) Approving OSHE and OFPM PAIs based on their completion of training; 398

(2) Maintaining a current list of approved PAIs; and 400

(3) Annually auditing designated area certificates and hot work permits to ensure that 402 program requirements are being met and records are being appropriately maintained. 403

f. PAIs are responsible for: 405

(1) Completing the PAI training module provided by OSHE on NFPA 51B and this suborder; 407

(2) Inspecting requested designated areas and permit-required areas against the requirements 409 of Appendix C; 410

(3) Upon determining that all applicable designated area or permit-required area 412 requirements have been met, issuing designated area certificates and hot work permits; 413

(4) Maintaining electronic or hard copies of all designated area certificates and hot work 415 permits for a minimum of one (1) year; and 416

(5) Making electronic or hard copies of all designated area certificates and hot work permits 418 available to the AHJ upon request. 419

g. NIST Employees Assigned to Conduct Fire Watches are responsible for: 421

(1) Completing the training provided by OSHE on this program; 423

(2) Completing annual training provided or approved by OSHE on the use of required fire 425 extinguishers; 426

(3) Stopping hot work and notifying the PAI if unsafe conditions develop; and 428

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(4) Knowing how to summon emergency help. 430

10. AUTHORITIES 433

For authorities applicable to all NIST Fire and Life Safety suborders, see NIST O 7401.00. 434

11. DIRECTIVE OWNER 437

Chief Safety Officer 438

12. APPENDICES 441

A. Revision History 442 B. Designated area certificate 443 C. Requirements for Designated Areas and Permit-Required Areas 444 D. Hot Work permit 445

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Appendix A. Revision History 448

Version No.

Approval Date

Effective Date Brief Description of Change; Rationale

1 09/30/17 04/01/2020 • None – Initial document

2 01/12/21 01/12/21 • Updated CFR links and NIST Suborder links.

3 04/25/25 04/25/25

• Reassigned responsibilities for Gaithersburg PAI from FPG to OSHE.

• Updated request procedure to reflect SPA website.

• Updated forms in Appendix B & D to reflect visual differences on the SPA website forms.

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Appendix B: Designated Area Certificate 452

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Appendix C. Requirements for Designated Areas and Permit-Required Areas 458

a. Designated Areas 460

(1) Designated areas shall be constructed of noncombustible or fire-resistive materials and 462 shall be free of combustible and flammable contents. 463

(a) All openings, holes, penetrations, or cracks in the fire-resistive construction shall be 465 sealed with fire-rated or noncombustible material to prevent the passage of sparks to 466 adjacent areas. 467

(2) Designated areas shall also meet the requirements for permit-required areas listed 469 below. 470

(3) Enclosed designated areas shall have a working ventilation system. The ductwork must 472 be noncombustible and not capable of transmitting sparks out of the area. 473

(4) A fire extinguisher having the appropriate classification for the hazard shall be 475 specified by the PAI for mounting immediately adjacent to the designated area. 476

b. Permit-Required Areas 478

(1) Floors shall be swept clean for a radius of 35 feet6,7 (11 meters) of the hot work site to 480 ensure combustible material, such as paper clippings, wood shavings, or textile fibers, 481 are not present. 482

(2) Floors constructed of a combustible material (e.g., wood) shall be kept wet, covered 484 with damp sand, or protected by a listed or approved welding blanket, welding pad, or 485 equivalent for a radius of 35 feet6, 7 (11 meters) of the hot work site. 486

6 In instances where the scope of work, tools used to conduct hot work, or size of the room/space in which hot work is conducted, are known to be incapable of generating or allowing slag, sparks, splatter, or similar mobile sources of ignition to travel farther than 35 feet (11 meters) from the hot work site, the PAI shall be permitted to reduce the distance. The approved distance shall be documented on the permit.

7 In instances where the scope of work and tools used to conduct hot work may result in the possible travel of slag, sparks, splatter, or similar mobile sources of ignition farther than 35 feet (11 meters) from the hot work site, the PAI shall extend the distance. The approved distance shall be documented on the permit.

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(3) Walls, partitions, ceilings, or roofs of combustible construction shall be protected from 488 hot works occurring near them by a listed or approved welding curtain, welding 489 blanket, welding pad, or equivalent. 490

(4) Ducts and conveyor systems located within 35 feet6, 7 (11 meters) of the hot work site 492 that might carry sparks to distant combustibles shall be shielded, shut down, or both. 493

(5) Openings, holes, penetrations, or cracks in walls, floors, or ducts within 35 feet6, 7 (11 495 meters) of the hot work site shall be covered or sealed with listed or approved fire-rated 496 or noncombustible material. 497

(6) All combustibles within 35 feet6, 7 (11 meters) of the hot work site shall be relocated. 499

(a) If relocation of combustibles is impractical, combustibles shall be protected by a 501 listed or approved welding curtain, welding blanket, welding pad, or equivalent. 502

(b) To prevent the entrance of sparks or slag, the edges of covers at the floor shall be 504 tight, including at the point at which several covers may overlap. 505

(7) For hot work performed in close proximity to a wall, partition, ceiling, or roof, 507 precautions shall be specified by the PAI to prevent ignition of combustibles that may 508 be located on the other side of the wall, partition, ceiling, or roof. 509

(8) For hot work performed in close proximity8 to a fire protection device, precautions 511 shall be specified by the PAI to prevent accidental operation of an automatic fire 512 detection or suppression system9. 513

(9) Fully charged and operable fire extinguishers appropriate for the type of possible fire 515 shall be specified by the PAI and available in the work area (e.g., within the 35-foot 516 perimeter or limits of the room/space). 517

(10) If existing hose lines are located within the hot work area defined by permit, they shall 519 be connected and ready for service but shall not be required to be unrolled or charged. 520

8 If sufficient heat, smoke, or particulate could be developed such that activation of fire protection devices would be likely, then the hot work would be deemed to be in “close proximity” to the fire protection devices.

9 Where fire alarm or fire suppression system impairments are necessary, the requirements of NIST S7401.03 shall be followed.

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c. Fire Watches 524

(1) The PAI may require a fire watch when hot work is performed under any of the 526 following circumstances: 527

(a) A fire protection system is impaired; 529

(b) A life safety system is impaired; or 531

(c) The requirements for a hot work permit are met, but the PAI is still concerned that 533 ignition from spark or slag could occur. 534

(2) A fire watch shall be maintained for a minimum of 30 minutes after completion of hot 536 work operations. 537

(a) The duration of a fire watch may be extended if the PAI determines the conditions 539 warrant an extension. 540

(3) The PAI shall determine the number of individuals needed to conduct a fire watch. 542

i. In some cases, it may be necessary to assign more than one employee to conduct 544 fire watch duties, e.g., where multiple floors are affected. 545

(4) The PAI shall determine the location(s) of the fire watch. 547

d. Non-Permissible Areas 549

(1) Hot work shall not be performed in the following areas.10 551

(a) In sprinklered buildings where sprinklers are impaired, unless the requirements of 553 NFPA 25, Standard for the Inspection, Testing, and Maintenance of Water-Based 554 Fire Protection are met and a fire watch is provided; 555

(b) In areas where explosive atmospheres may be present, i.e., where mixtures of 557 flammable gases, vapors, liquids, or dusts with air exist; 558

(c) In areas where contaminated equipment, drums, tanks, or other containers that have 560 previously contained materials that could develop explosive atmospheres may be 561 present; 562

10 In such areas, techniques other than hot works must be utilized.

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(d) On a partition, wall, ceiling, or roof with a combustible covering and/or insulation, 563 or combustible sandwich-type panel construction; and 564

(e) On pipes or other metal that is in contact with combustible walls, ceilings, roofs, or 566 other combustibles if the work is close enough to cause ignition by conduction. 567

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Appendix D: Hot Work Permit 569

Appendix A. Revision History