California Code of Regulations
Title 8 - Industrial Relations
Division 1 - Department of Industrial Relations
Chapter 4 - Division of Industrial Safety
Subchapter 7 - General Industry Safety Orders
Group 20 - Flammable Liquids, Gases and Vapors
Article 138 - Hydrogen
Section 5473 - Specific Requirements
Current through Register 2024 Notice Reg. No. 38, September 20, 2024
(a) The location of a system, as determined by the maximum total contained volume of hydrogen, shall be in the order of preference as indicated by Roman numerals in Table H-1.
Table H-1
| Size of Hydrogen System | |||
| Nature of Location | Less than 3,000 CF | 3,000 CF to 15,000 CF | In Excess of 15,000 CF |
| Outdoors | I | I | I |
| In a separate building | II | II | II |
| In a special room | III | III | Not Permitted |
| Inside buildings not in a special room and exposed to other occupancies | IV | Not Permitted | Not Permitted |
(b) The minimum distance in feet from a hydrogen system of indicated capacity located outdoors, in separate buildings or in special rooms to any specified outdoor exposure shall be in accordance with Table H-2.
(c) The distance in Table H-2, Items 1, 14 and 3 to 10 inclusive do not apply where protective structures such as adequate fire walls are located between the system and the exposure.
(d) Hydrogen systems of less than 3,000 CF when located inside buildings and exposed to other occupancies shall be situated in the building so that the system will be as follows:
Table H-2
| Size of Hydrogen System | ||||||
| Type of Outdoor Exposure | Less than 3,000 CF | 3,000 CF to 15,000 CF | In Excess of 15,000 CF | |||
| 1. | Building or | Wood Frame Construction* | 10 | 25 | 50 | |
| Structure | Heavy Timber, Noncombustible or Ordinary Construction* | 0 | 10 | 25* | ||
| Fire Resistive Construction* | 0 | 0 | 0 | |||
| 2. | Wall Openings | Not above any part of a system | 10 | 10 | 10 | |
| Above any part of a system | 25 | 25 | 25 | |||
| 3. | Flammable liquids | 0-1,000 gallons | 10 | 25 | 25 | |
| above ground | In excess of 1,000 gallons | 25 | 50 | 50 | ||
| 4. | Flammable liquids | Tank | 10 | 10 | 10 | |
| below ground-- | ||||||
| 0-1,000 gallons | Vent or fill opening of tank | 25 | 25 | 25 | ||
| 5. | Flammable liquids | Tank | 20 | 20 | 20 | |
| below ground-- | ||||||
| in excess of 1,000 gallons | Vent or fill opening of tank | 25 | 25 | 25 | ||
| 6. | Flammable gas storage | 0-15,000 CF capacity | 10 | 25 | 25 | |
| age, either high | ||||||
| pressure or low pressure | in excess of 15,000 CF capacity | 25 | 50 | 50 | ||
| 7. | Oxygen Storage | 12,000 CF or less | Refer to NFPA No. 51, Gas Systems for Welding and Cutting | |||
| More than 12,000 CF | Refer to NFPA No. 50, Bulk Oxygen Systems at Consumer Sites | |||||
| 8. | Fast burning solids such as ordinary lumber, excelsior or paper | 50 | 50 | 50 | ||
| 9. | Slow burning solids such as heavy timber or coal | 25 | 25 | 25 | ||
| 10. | Open flames and other sources of ignition | 25 | 25 | 25 | ||
| 11. | Air compressor intakes or inlets to ventilating or air-conditioning equipment | 50 | 50 | 50 | ||
| 12. | Concentration of people*** | 25 | 50 | 50 | ||
| 13. | Public Sidewalks | 15 | 15 | 15 | ||
| 14. | Line of adjoining property which may be built upon | 5 | 5 | 5 | ||
* Refer to NFPA No. 220, Standard Types of Building Construction for definitions of various types of construction.
** But not less than one-half the height of adjacent side wall of the structure.
*** In congested areas such as offices, lunchrooms, locker rooms, time-clock areas and places of public assembly.
1. Editorial correction of Table H-2 (Register 76, No. 9).
