CRSC · California Referenced Standards Code
What are the operator‑station shielding requirements?
If you operate or design an x‑ray control area, the operator must be placed behind a protective barrier (separate room, protected booth, or shield) that intercepts the primary (useful) beam and any single‑scattered radiation; observation windows must have the same attenuation as the surrounding barrier and a certified physicist must specify barrier amounts. **§ 3103C.1** and related sections set these requirements.
Last reviewed: July 6, 2026
What the code requires — plain English
The operator’s station (control position) must be behind a protective barrier — either in a separate room, a protected booth, or behind a shield — that will intercept the useful beam and any radiation that has been scattered only once. This requirement is set out in § 3103C.1.
The operator must remain in a shielded position so the barrier intercepts the primary x‑ray beam and any single‑scattered radiation before it reaches the operator. § 3103C.1 is the controlling rule.
Requirements in detail
Key defined terms (first mention)
- Protective barrier — any construction (room, booth or shield) intended to stop or attenuate radiation at the operator station. § 3103C.1.
- Useful beam — the useful diagnostic beam that issues from the tube housing/collimator. § 3101C (definitions).
- Scattered only once — radiation that has been scattered a single time (i.e., first‑order scatter); the barrier must intercept the useful beam and radiation scattered once. § 3103C.1.
Decision‑relevant dimensions and values
| Decision factor | Required value / description | Code Reference |
|---|---|---|
| Operator location | Separate room, protected booth, or behind shield that places the operator behind a barrier | § 3103C.1 |
| Beam interception | Barrier must intercept the useful beam and any radiation scattered only once (i.e., block primary and single scatter paths to operator) | § 3103C.1 |
| Observation window (if used) | Window must provide radiation attenuation equal to the surrounding barrier so the shielded position is continuous | § 3103C.2 |
| Where shielding specs come from | Shielding type, location and amount must comply with radiation shielding standards (see Standard 12‑31C‑1) and be specified by a qualified physicist for medical imaging layouts | § 3102C and Standard 12‑31C‑1; also see requirement for a certified physicist in § 1224.18.1.1. |
| Equipment >50 kVp (therapeutic/medical x‑ray) | Control station shielding must be integral to building or anchored; window attenuation equal to adjacent barrier or alternate viewing means (mirror/CCTV) | § 3104C.2 |
Notes on the table:
- The code sets placement and performance objectives (what the barrier must do) but does not list single universal thicknesses or lead‑equivalents in § 3103C.1 — those are determined by engineering/shielding calculations and the referenced shielding standard.
Who specifies the thickness/amount of shielding
- A certified physicist or other qualified expert must specify the type, location and amount of radiation protection to be installed in imaging areas; the construction documents must incorporate those requirements. § 1224.18.1.1.
- All shielding must meet the requirements of Standard 12‑31C‑1 (Radiation shielding standards). § 3102C references these standards.
Exceptions & special cases
- The code text of § 3103C.1 does not list explicit exceptions to the location/shielding requirement; variability in materials/thickness is handled by shielding calculations per Standard 12‑31C‑1 and by the responsible health agency.
- Variances to the referenced shielding standards may be granted only by the Department of Health Services (as noted for radiation shielding barriers). § 3102C notes the Department of Health Services as the agency authorized to grant variances.
- For equipment operating at higher energies (therapeutic machines) additional control‑station rules apply (anchoring, interlocks, viewing alternatives). See § 3104C.2–3104C.3 for these special provisions.
Common mistakes
- Assuming “a shield” can be an un‑specified screen: the barrier must intercept the useful beam and single scatter; merely being behind a partial partition that does not intercept the beam is noncompliant. § 3103C.1.
- Using an observation window without matching attenuation: any window used for patient observation must provide attenuation equal to the surrounding barrier per § 3103C.2.
- Designing barrier thickness by rule of thumb instead of calculation: the code expects a qualified physicist to specify shielding amounts and compliance with Standard 12‑31C‑1 — don’t invent lead‑equivalence numbers without calculation.
- Overlooking equipment‑specific rules: for machines >50 kVp or >150 kVp, the control station and interlocks have additional requirements in § 3104C.
Worked example
Scenario: A clinic installs a diagnostic fluoroscopy room. The operator will work from a control position with a view of the patient through a leaded‑glass window.
Step 1 — Location: Place the operator’s station so it is behind a protective barrier — here, a sealed control booth with leaded‑glass observation window. This meets the location options listed in § 3103C.1.
Step 2 — Window attenuation: Ensure the observation window provides radiation attenuation equal to the surrounding barrier so the operator remains continuously protected. That is the requirement of § 3103C.2.
Step 3 — Shielding amount: Contract a certified physicist to calculate the lead equivalence (or other material specification) based on workload, use factor, distances and occupancy factors. The certified physicist requirement and incorporation into construction documents is specified in § 1224.18.1.1, and the shielding calculations use Standard 12‑31C‑1 as the technical basis referenced by § 3102C.
Important caveat: the CRSC text in § 3103C.1 describes placement and performance expectations but does not list numeric lead‑thicknesses or mR limits in that section; those numbers are supplied by the shielding standard and by the physicist’s site‑specific calculations.
Related provisions
- § 3103C.2 — Patient observation and communication; windows must provide attenuation equal to surrounding barrier.
- § 3102C — All radiation shielding barriers must meet Standard 12‑31C‑1; variances granted by Department of Health Services.
- § 3104C.2 — For equipment operating above 50 kVp, control station shielding anchoring and window/viewing requirements.
- § 3104C.3 — Additional control‑station and interlock rules for equipment above 150 kVp.
- § 1224.18.1.1 — A certified physicist or qualified expert must specify type, location and amount of radiation protection; include these specs in construction documents.
- Standard 12‑31C‑1 (Chapter 12‑31C, Part 12) — The radiation‑shielding engineering standard that provides the technical criteria and calculation methods for barrier design.
Code references
Grounded in the retrieved California Referenced Standards Code — click a citation to read the verbatim passage:
CRSC § 1.11. High relevance — show source text
The state agency does not adopt sections identified with the following symbol: The Office of the State Fire Marshal’s adoption of this chapter or individual sections is applicable to structures regulated by other state agencies pursuant to Section 1.11.
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31C [DPH] RADIATION
SECTION 3101C—SCOPE
For the purpose of this chapter, the following terms shall have the meaning indicated:
PRIMARY PROTECTIVE BARRIER is a barrier to attenuate the useful beam.
SECONDARY PROTECTIVE BARRIER is a barrier to attenuate stray radiation.
STRAY RADIATION is radiation not serving any useful purpose, which includes leakage and scattered radiation.
USEFUL BEAM is the radiation which passes through the window, aperture, cone or other collimating device of the tube housing.
SECTION 3102C—RADIATION SHIELDING BARRIERS
All radiation shielding barriers in rooms and enclosures housing machines shall meet the requirements of Section 12-31C-101, Chapter 12-31C, Part 12, California Referenced Standards Code. The Department of Health Services is the only agency that may grant a variance or exception to these standards.
SECTION 3103C—MEDICAL RADIOGRAPHIC AND PHOTOFLUOROGRAPHIC INSTALLATIONS
3103C.1 Operator station. The operator’s station at the control shall be behind a protective barrier either in a separate room, in a protected booth or behind a shield which will intercept the useful beam and any radiation which has been scattered only once.
3103C.2 Patient observation and communication. Provision shall be made for the operator to observe and communicate with the patient without leaving the shielded position at the control panel. When an observation window is used, it must provide radiation atten- uation equal to that required in the surrounding barrier.
SECTION 3104C—MEDICAL THERAPEUTIC X-RAY INSTALLATIONS
3104C.1 General. All wall, floor and ceiling areas that can be struck by the useful beam, plus a border of 1 foot (305 mm), shall be provided with primary protective barriers.
3104C.2 Equipment operating above 50 kVp. Equipment operating above 50 kVp shall conform with the following: 1. The control station shielding shall either be an integral part of the building or anchored to the building. 2. The control station shall be provided with a window having radiation attenuation equal to that required by the adjacent barrier, or a mirror system, or a closed-circuit television viewing screen. The patient area must be visible to the operator with- out having to leave the protected area during exposure.
CRSC § 3103C.1 High relevance — show source text
SECTION 3103C—MEDICAL RADIOGRAPHIC AND PHOTOFLUOROGRAPHIC INSTALLATIONS
3103C.1 Operator station. The operator’s station at the control shall be behind a protective barrier either in a separate room, in a protected booth or behind a shield which will intercept the useful beam and any radiation which has been scattered only once.
3103C.2 Patient observation and communication. Provision shall be made for the operator to observe and communicate with the patient without leaving the shielded position at the control panel. When an observation window is used, it must provide radiation atten- uation equal to that required in the surrounding barrier.
SECTION 3104C—MEDICAL THERAPEUTIC X-RAY INSTALLATIONS
3104C.1 General. All wall, floor and ceiling areas that can be struck by the useful beam, plus a border of 1 foot (305 mm), shall be provided with primary protective barriers.
3104C.2 Equipment operating above 50 kVp. Equipment operating above 50 kVp shall conform with the following: 1. The control station shielding shall either be an integral part of the building or anchored to the building. 2. The control station shall be provided with a window having radiation attenuation equal to that required by the adjacent barrier, or a mirror system, or a closed-circuit television viewing screen. The patient area must be visible to the operator with- out having to leave the protected area during exposure.
3104C.3 Equipment operating above 150 kVp. Equipment operating above 150 kVp shall conform to the following: 1. The treatment room shall be provided with interlocks so that when any door of the treatment room is opened, either the machine will shut off automatically or the radiation level within the room will be reduced to an average of not more than 2 milliroentgens per hour and a maximum of 10 milliroentgens per hour at a distance of one meter in any direction from the target. After such shutoff or reduction in output, it shall be possible to restore the machine to full operation only from the control panel. 2. The control station shall be within a protective booth or in an adjacent room.
3104C.4 A minimum of one door shall be provided with an auxiliary means for being opened in case of power failure or mechanical breakdown, where large power-driven doors offer the only access to the room.
3104C.5 A flashing red warning signal light energized only when the useful beam is on shall be located adjacent to the entrance(s) to a therapy room with equipment capable of operating above 500 kVp.
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CALIFORNIA BUILDING CODE – MATRIX ADOPTION TABLE
CHAPTER 31D – FOOD ESTABLISHMENTS
(Matrix Adoption Tables are nonregulatory, intended only as an aid to the code user. See Chapter 1 for state agency authority and building applications.)
CRSC § 1.11. Medium relevance — show source text
CALIFORNIA BUILDING CODE – MATRIX ADOPTION TABLE
CHAPTER 31C – RADIATION
(Matrix Adoption Tables are nonregulatory, intended only as an aid to the code user. See Chapter 1 for state agency authority and building applications.)
Adopting agency BSC BSC-
CGSFM HCD Col6 Col7 DSA Col9 Col10 OSHPD Col12 Col13 Col14 Col15 Col16 Col17 BSCC DPH AGR DWR CEC CA SL SLC Adopting agency BSC BSC-
CGSFM 1 2 1/AC AC SS SS/CC 1 1R 2 3 4 5 6 6 6 6 6 6 6 6 6 Adopt entire chapter X Adopt entire chapter as
amended (amended
sections listed below)Adopt only those sections
that are listed belowChapter / Section The state agency does not adopt sections identified with the following symbol: The Office of the State Fire Marshal’s adoption of this chapter or individual sections is applicable to structures regulated by other state agencies pursuant to Section 1.11.
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31C [DPH] RADIATION
SECTION 3101C—SCOPE
For the purpose of this chapter, the following terms shall have the meaning indicated:
PRIMARY PROTECTIVE BARRIER is a barrier to attenuate the useful beam.
SECONDARY PROTECTIVE BARRIER is a barrier to attenuate stray radiation.
STRAY RADIATION is radiation not serving any useful purpose, which includes leakage and scattered radiation.
USEFUL BEAM is the radiation which passes through the window, aperture, cone or other collimating device of the tube housing.
SECTION 3102C—RADIATION SHIELDING BARRIERS
All radiation shielding barriers in rooms and enclosures housing machines shall meet the requirements of Section 12-31C-101, Chapter 12-31C, Part 12, California Referenced Standards Code. The Department of Health Services is the only agency that may grant a variance or exception to these standards.
SECTION 3103C—MEDICAL RADIOGRAPHIC AND PHOTOFLUOROGRAPHIC INSTALLATIONS
CRSC § 1224.18.4.1 Medium relevance — show source text
The room or_ area shall be outside the restricted areas of the MRI’s magnetic field. 3. Safety Zones One through Four shall be identified. a) Zone One consists of all areas freely accessible to the general public. This zone includes the entrance to the MR facility. b) Zone Two acts as a buffer between Zone One and the more restrictive Zone Three. Patients are under the general supervision of MR personnel. Zone Two may include the reception area, dressing room and interview room. c) Zone Three should be restricted by a physical barrier. The MR control room and/or computer room are located within Zone Three.
d) Zone Four is strictly the area within the walls of the MR scanner room. Access into the MR scanner room should only be available by passing through Zone Three. 4. An imaging equipment room shall be provided if needed for the operation of the MRI.
1224.18.4.1 Handwashing station. Handwashing station(s) shall be immediately accessible to the MRI scanner room.
1224.18.4.2 Wall, floor and ceiling assemblies. Wall, floor and ceiling assemblies shall accommodate the installation of required radio frequency (RF)-shielded assemblies. All doors, windows and penetrations into the RF-shielded enclosure shall be RF- shielded. As well as RF shielding, individual sites may also require magnetic shielding on some or all surfaces to contain portions of the magnetic field not contained by the RF shield.
1224.18.4.3 Lighted sign. MRI rooms shall be clearly marked with a red light and lighted sign stating, “The Magnet Is On”. This light and sign are to be lighted at all times and have a backup energy source to remain illuminated for at least 24 hours in the event of a loss of power.
1224.18.4.4 Magnetic field strength identification. Facilities shall use finishes or markings to identify the critical values of the magnetic field surrounding the MRI scanner, including the 5-gauss exclusion zone or other magnetic field strength values that may impair the operation of equipment.
1224.18.4.5 Special ventilation requirements. Where superconducting MRI scanners are installed, an insulated cryogen quench exhaust pipe as well as room exhaust and pressure equalization shall be provided to protect occupants in the event of a cryogen breach.
1224.18.4.6 Intraoperative magnetic resonance imaging. If provided, the intraoperative magnetic resonance imaging (iMRI) suite shall comply with Section 1224.28.5.
1224.18.5 Ultrasound. When provided, the ultrasound room shall comply with the following:
1224.18.5.1 Space requirements. 1. Area. Rooms used for ultrasound examination/treatment shall have a minimum clear floor area of 120 square feet (11.15 m [2] ). 2. Clearances. A minimum clear dimension of 3 feet (914 mm) shall be provided on three sides of the table/stretcher.
1224.18.5.2 Handwashing station. A handwashing station shall be provided within the exam room.
CRSC § 12-16 Medium relevance — show source text
12-16-1 ENGINEERING REGULATIONS—QUALITY AND
DESIGN OF THE MATERIALS OF CONSTRUCTION
CALIFORNIA STANDARD FOR EARTHQUAKE-ACTUATED AUTOMATIC GAS SHUTOFF SYSTEMS (SEE CCR TITLE 24, PART 2, CHAPTERS 16 AND 16A, AND CCR TITLE 24, PART 5, CHAPTER 12) STANDARD 12-16-1
DIVISION OF THE STATE ARCHITECT
Authority: Sections 19180–19183, Health and Safety Code. Reference: Section 19182, Health and Safety Code.
DIVISION 1—CONSTRUCTION
SCOPE
Sec. 12-16-101. The American Society of Civil Engineers (ASCE) requirements for “Earthquake-Actuated Automatic Gas Shutoff Devices,” ANSI/ASCE/SEI 25-16 (copyright 2016 by ASCE), shall be the applicable standard used by the Division of the State Architect for the certification of these devices.
Sec. 12-16-101.1. Each installation of a customer-owned device that satisfies this standard shall be in accordance with the California Plumbing Code (CCR Title 24, Part 5).
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12-16-2 ENGINEERING REGULATIONS—QUALITY AND
DESIGN OF THE MATERIALS OF CONSTRUCTION
CALIFORNIA STANDARD FOR RESIDENTIAL EXCESS FLOW ACTUATED AUTOMATIC GAS SHUTOFF VALVES (SEE CCR TITLE 24, PART 5, CHAPTER 12) STANDARD 12-16-2
DIVISION OF THE STATE ARCHITECT
Authority: Sections 19200–19204, Health and Safety Code. Reference: Sections 19201.5 and 19202, Health and Safety Code.
DIVISION 1—CONSTRUCTION
SCOPE
Sec. 12-16-201. The American Society for Testing and Materials (ASTM) F2138-12(2017) Standard Specification for Excess Flow Valves for Natural Gas Service, and the American National Standards Institute (ANSI) Z21.93-2017/CSA 6.30-2017 Excess Flow Valves for Natural and LP Gas with Pressure up to 5 psig, shall be the applicable standards used by the Division of the State Architect for certification of these devices.
Sec. 12-16-201.1. Each installation of a customer-owned device that satisfies this standard shall be in accordance with the California Plumbing Code (CCR Title 24, Part 5).
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12-31C RADIATION SHIELDING STANDARDS
STANDARD 12-31C-1
DEPARTMENT OF HEALTH SERVICES
CRSC § 7.62 Medium relevance — show source text
- For occupancies in Groups R-2 and R-3, within the interior conditioned space of individual dwelling units, where the open-sided walking surface is located not more than 25 feet (7.62 meters) measured vertically to the floor or walking surface below, required guards shall not be less than 36 inches (914 mm) in height measured vertically above the adjacent walking surface. 3. For occupancies in Group R-3, and within individual dwelling units in occupancies in Group R-2, where the top of the guard serves as a handrail on the open sides of stairs, the top of the guard shall be not less than 34 inches (864 mm) and not more than 38 inches (965 mm) measured vertically from a line connecting the nosings. 4. The guard height in assembly seating areas shall comply with Section 1030.17 as applicable. 5. Along alternating tread devices and ship’s ladders, guards where the top rail serves as a handrail shall have height not less than 30 inches (762 mm) and not more than 34 inches (864 mm), measured vertically from a line connecting the leading edge of the treads. 6. In Group F occupancies where exit access stairways serve fewer than three stories and such stairways are not open to the public, and where the top of the guard also serves as a handrail, the top of the guard shall be not less than 34 inches (864 mm) and not more than 38 inches (965 mm) measured vertically from a line connecting the nosings.
[BE] 1015.4 Opening limitations. Required guards shall not have openings that allow passage of a sphere 4 inches (102 mm) in diameter from the walking surface to the required guard height.
Exceptions:
- From a height of 36 inches (914 mm) to 42 inches (1067 mm), guards shall not have openings that allow passage of a sphere 4 [3] / 8 inches (111 mm) in diameter.
- The triangular openings at the open sides of a stair, formed by the riser, tread and bottom rail shall not allow passage of a sphere 6 inches (152 mm) in diameter.
- At elevated walking surfaces for access to and use of electrical, mechanical or plumbing systems or equipment, guards shall not have openings that allow passage of a sphere 21 inches (533 mm) in diameter.
- In areas that are not open to the public within occupancies in Group I-3, F, H or S, and for alternating tread devices and ship’s ladders, guards shall not have openings that allow passage of a sphere 21 inches (533 mm) in diameter.
- In assembly seating areas, guards required at the end of aisles in accordance with Section 1030.17.4 shall not have openings that allow passage of a sphere 4 inches (102 mm) in diameter up to a height of 26 inches (660 mm). From a height of 26 inches (660 mm) to 42 inches (1067 mm) above the adjacent walking surfaces, guards shall not have openings that allow passage of a sphere 8 inches (203 mm) in diameter.
- Within individual dwelling units and sleeping units in Group R-2 and R-3 occupancies, guards on the open sides of stairs shall not have openings that allow passage of a sphere 4 [3] / 8 (111 mm) inches in diameter. 7. [SFM] In lifeguard towers not open to the public, guards shall not have openings which allow passage of a sphere 21 inches (533 mm) in diameter.
CRSC § 1224.15.2.1 Medium relevance — show source text
Where imaging procedures meeting Class 3 criteria are performed, rooms that meet the requirements_ for the applicable imaging suite and for an operating room per Section 1224.15.2.1 or hybrid operating room per Section 1224.28.5 shall be provided. If Class 3 interventional or image-guided procedures are performed in the imaging services area, additional provisions shall be as described in Section 1224.28 Supplemental Surgery and other Special Procedure Services. If nuclear medicine is provided in the imaging services area, spaces shall also comply with the requirements described in Section 1224.34 Nuclear Medicine.
1224.18.1 Minimum requirements. Hospital shall provide a minimum of: 1. One fluoroscopy room or CT room on approval of Licensing Agency, which can also provide x-ray examination services. 2. Space for processing or viewing images. 3. A toilet room shall adjoin and be directly accessible to each fluoroscopy room. In addition to the fluoroscopy toilet rooms, common patient toilet room facilities shall be located in the radiological/diagnostic imaging service space. 4. An office or other suitable area for viewing and reporting radiographic examination. 5. Storage spaces for all image equipment, supplies and copies of reports. 6. Handwashing stations located within the unit. a) Handwashing station(s) shall be provided within the unit to serve imaging spaces not served by a dedicated hand- washing station within the imaging room or scrub facility located directly outside the imaging/procedure room. b) A handwashing station shall be provided in Class 1 imaging rooms, unless specified otherwise for a specific imaging modality. c) A handwashing station or hand scrub facility shall be provided for Class 2 imaging rooms. If a handwashing station is provided, it shall be directly accessible to the imaging room. If a hand scrub facility is provided, it shall be directly outside the entrance to the imaging room. d) Hand scrub facilities shall be provided directly outside the entrance to a Class 3 imaging room. 7. Dressing room facilities.
1224.18.1.1 Radiation protection. A certified physicist or other qualified expert shall specify the type, location and amount of radiation protection to be installed in accordance with the final approved department layout and equipment selections. Where protected alcoves with view windows are required, a minimum of 1'-6" (0.45 meter) between the view window and the outside partition edge shall be provided. Radiation protection requirements shall be incorporated into the construction documents and comply with Chapter 31C and the requirements of California Radiation Control Regulations, California Code of Regulations, Title 17, Division 1, Chapter 5 and Subchapter 4. 1. The control alcove or room shall be, at minimum, sized and configured in compliance with the manufacturer’s recom- mendations for installation, service and maintenance.
2. A control alcove or room shall be permitted to serve more than one imaging room, provided the manufacturer’s recom- mendations for installation, service and maintenance are accommodated for all rooms served.
CRSC § 1.5 Medium relevance — show source text
2, or as rated
in accordance with AHRI Standard 680 for the design airflow rate for the return grille.| |SYSTEM NOMINAL
COOLING CAPACITY
(Ton)*|RETURN DUCT 1
MINIMUM NOMINAL DIAMETER
(inch)|RETURN DUCT 2
MINIMUM NOMINAL DIAMETER
(inch)|MINIMUM TOTAL RETURN
FILTER GRILLE NOMINAL AREA
(inch2)| |1.5|12|10|500| |2.0|14|12|600| |2.5|14|14|800| |3.0|16|14|900| |3.5|16|16|1000| |4.0|18|18|1200| |5.0|20|20|1500| |*Not applicable to systems with nominal cooling capacity greater than 5.0 tons or less than 1.5 tons.|*Not applicable to systems with nominal cooling capacity greater than 5.0 tons or less than 1.5 tons.|*Not applicable to systems with nominal cooling capacity greater than 5.0 tons or less than 1.5 tons.|*Not applicable to systems with nominal cooling capacity greater than 5.0 tons or less than 1.5 tons.|2025 CALIFORNIA ENERGY CODE 169
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SINGLE-FAMILY RESIDENTIAL BUILDINGS— MANDATORY FEATURES AND DEVICES
TABLE 150.0-D—INFILTRATION EFFECTIVENESS WEATHER AND SHIELDING FACTORS [ASHRAE 62.2:TABLE B1] Col2 Col3 Col4 Col5 Col6 TMY3 WSF WEATHER STATION LATITUDE LONGITUDE STATE 690150 0.50 Twentynine Palms 34.30 –116.17 California 722860 0.43 March AFB 33.90 –117.25 California 722868 0.45 Palm Springs Intl 33.83 –116.50 California 722869 0.42 Riverside Muni 33.95 –117.45 California 722880 0.39 Burbank–Glendale–Pasadena AP 34.20 –118.35 California 722885 0.39 Santa Monica Muni 34.02 –118.45 California 722886 0.39 Van Nuys Airport 34.22 –118.48 California 722895 0.55 Lompoc (AWOS) 34.67 –120.47 California 722897 0.51 San Luis Co Rgnl 35.23 –120.63 California 722899 0.45 Chino Airport 33.97 –117.63 California 722900 0.38 San Diego Lindbergh Field 32.73 –117.17 California 722903 0.39 San Diego/Montgomery 32.82 –117.13 California 722904 0. CRSC § 2.2.6 Medium relevance — show source text
Tabulated values are for clear-span roof supported solely by exterior bearing walls.
b. Spans are based on No. 2 Grade lumber of Douglas fir-larch, Southern pine, hem-fir and spruce-pine-fir for repetitive (three or more) members.
c. Ratio of backspan to cantilever span shall be not less than 3:1.
d. Connections capable of resisting the indicated uplift force shall be provided at the backspan support.
e. Uplift force is for a backspan to cantilever span ratio of 3:1. Tabulated uplift values are permitted to be reduced by multiplying by a factor equal to 3 divided by the actual
backspan ratio provided (3/backspan ratio).
f. See Section R301.2.2.6, Item 1, for additional limitations on cantilevered floor joists for detached one- and two-family dwellings in Seismic Design Category D0, D1 or D2 and
townhouses in Seismic Design Category C, D0, D1 or D2.
g. Linear interpolation shall be permitted for building widths and ground snow loads other than shown.|For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot = 0.0479 kPa.
a. Tabulated values are for clear-span roof supported solely by exterior bearing walls.
b. Spans are based on No. 2 Grade lumber of Douglas fir-larch, Southern pine, hem-fir and spruce-pine-fir for repetitive (three or more) members.
c. Ratio of backspan to cantilever span shall be not less than 3:1.
d. Connections capable of resisting the indicated uplift force shall be provided at the backspan support.
e. Uplift force is for a backspan to cantilever span ratio of 3:1. Tabulated uplift values are permitted to be reduced by multiplying by a factor equal to 3 divided by the actual
backspan ratio provided (3/backspan ratio).
f. See Section R301.2.2.6, Item 1, for additional limitations on cantilevered floor joists for detached one- and two-family dwellings in Seismic Design Category D0, D1 or D2 and
townhouses in Seismic Design Category C, D0, D1 or D2.
g. Linear interpolation shall be permitted for building widths and ground snow loads other than shown.|For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot = 0.0479 kPa.
a. Tabulated values are for clear-span roof supported solely by exterior bearing walls.
b. Spans are based on No. 2 Grade lumber of Douglas fir-larch, Southern pine, hem-fir and spruce-pine-fir for repetitive (three or more) members.
c. Ratio of backspan to cantilever span shall be not less than 3:1.
d. Connections capable of resisting the indicated uplift force shall be provided at the backspan support.
e. Uplift force is for a backspan to cantilever span ratio of 3:1. Tabulated uplift values are permitted to be reduced by multiplying by a factor equal to 3 divided by the actual
backspan ratio provided (3/backspan ratio).
f.CRSC § 3501.4 Medium relevance — show source text
Areas where the automatic sprinkler system is impaired.
Areas where there exists the potential of an explosive atmosphere, such as locations where flammable gases, liquids or vapors are present.
Areas with readily ignitable materials, such as storage of large quantities of bulk sulfur, baled paper, cotton, lint, dust or loose combustible materials.
On board ships at dock or ships under construction or repair.
At other locations as specified by the fire code official.
3501.4 Cylinders and containers. Compressed gas cylinders and fuel containers shall comply with this chapter and Chapter 53.
3501.5 Design and installation of oxygen-fuel gas systems. An oxygen-fuel gas system with two or more manifolded cylinders of oxygen shall be in accordance with NFPA 51.
SECTION 3502—DEFINITIONS
3502.1 Definitions. The following terms are defined in Chapter 2:
HOT WORK.
HOT WORK AREA.
HOT WORK EQUIPMENT.
HOT WORK PERMITS.
HOT WORK PROGRAM.
RESPONSIBLE PERSON.
SECTION 3503—GENERAL REQUIREMENTS
3503.1 General. Hot work conditions and operations shall comply with this chapter.
3503.2 Temporary and fixed hot work areas. Temporary and fixed hot work areas shall comply with this section.
3503.3 Hot work program permit. Hot work permits, issued by an approved responsible person under a hot work program, shall be available for review by the fire code official at the time the work is conducted and for 48 hours after work is complete.
3503.4 Qualifications of operators. A permit for hot work operations shall not be issued unless the individuals in charge of performing such operations are capable of performing such operations safely. Demonstration of a working knowledge of the provisions of this chapter shall constitute acceptable evidence of compliance with this requirement.
3503.5 Records. The individual responsible for the hot work area shall maintain “prework check” reports in accordance with Section 3504.3.1. Such reports shall be maintained on the premises for not less than 48 hours after work is complete.
3503.6 Signage. Visible hazard identification signs shall be provided where required by Chapter 50. Where the hot work area is open to persons other than the operator of the hot work equipment, conspicuous signs shall be posted to warn others before they enter the hot work area. Such signs shall display the following warning:
CAUTION
HOT WORK IN PROGRESS
STAY CLEAR
2025 CALIFORNIA FIRE CODE 35-3
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
WELDING AND OTHER HOT WORK
SECTION 3504—FIRE SAFETY REQUIREMENTS
3504.1 Protection of combustibles. Protection of combustibles shall be in accordance with Sections 3504.1.1 through 3504.1.9.
3504.1.1 Combustibles. Hot work areas shall not contain combustibles or shall be provided with appropriate shielding to prevent sparks, slag or heat from igniting exposed combustibles.
3504.1.2 Openings. Openings or cracks in walls, floors, ducts or shafts within the hot work area shall be tightly covered to prevent the passage of sparks to adjacent combustible areas, or shielded by metal fire-resistant guards, or curtains shall be provided to prevent passage of sparks or slag.
CRSC § 1207.6 Medium relevance — show source text
TABLE 1207.6—ELECTROCHEMICAL ESS TECHNOLOGY-SPECIFIC REQUIREMENTS Col2 Col3 Col4 Col5 Col6 Col7 Col8 Col9 Col10 COMPLIANCE REQUIREDb COMPLIANCE REQUIREDb BATTERY TECHNOLOGY BATTERY TECHNOLOGY BATTERY TECHNOLOGY BATTERY TECHNOLOGY BATTERY TECHNOLOGY BATTERY TECHNOLOGY OTHER ESS
AND BATTERY
TECHNOLOGIESbCAPACITOR
ESSbFeature Section Lead-
acidNickel
cadmium
(Ni-Cd),
nickel-metal
hydride
(Ni-MH) and
nickel zinc
(Ni-Zn)Zinc-
manganese
dioxide
(Zn-MnO2)Lithium-ion Flow Sodium
nickel
chlorideSodium
nickel
chlorideSodium
nickel
chlorideExhaust
ventilation1207.6.1 Yes Yes Yes No Yes No Yes Yes Explosion control 1207.6.3 Yesa Yesa Yes Yes No Yes Yes Yes Safety caps 1207.6.4 Yes Yes No No No No Yes Yes Spill control and
neutralization1207.6.2 Yesc Yesc Yesf No Yes No Yes Yes Thermal
runaway1207.6.5 Yesd Yes Yese Yese No Yes Yese Yes a. Not required for lead-acid and nickel-cadmium batteries at facilities under the exclusive control of communications utilities that comply with NFPA 76 and operate at less
than 50 VAC and 60 VDC.
b. Protection shall be provided unless documentation acceptable to the fire code official is provided in accordance with Section 104.2.2 that provides justification why the
protection is not necessary based on the technology used.
c. Applicable to vented-type (i.e., flooded) nickel-cadmium and lead-acid batteries.
d. Not required for vented-type (i.e., flooded) batteries.
e. The thermal runaway protection is permitted to be part of a battery management system that has been evaluated with the battery as part of the evaluation to UL 1973.
f. Not required for batteries with jelled electrolyte.a. Not required for lead-acid and nickel-cadmium batteries at facilities under the exclusive control of communications utilities that comply with NFPA 76 and operate at less
than 50 VAC and 60 VDC.
b. Protection shall be provided unless documentation acceptable to the fire code official is provided in accordance with Section 104.2.2 that provides justification why the
protection is not necessary based on the technology used.
c.CRSC § 37.28 Medium relevance — show source text
46|Merced/Macready Fld|37.28|–120.52|California| |724830|0.51|Sacramento Executive Arpt|38.50|–121.50|California| |724837|0.45|Beale AFB|39.13|–121.43|California| |724838|0.50|Yuba Co|39.10|–121.57|California| |724839|0.51|Sacramento Metropolitan AP|38.70|–121.58|California| |724915|0.49|Monterey Naf|36.60|–121.87|California| |724917|0.54|Salinas Municipal AP|36.67|–121.60|California| |724920|0.50|Stockton Metropolitan Arpt|37.90|–121.23|California| |724926|0.47|Modesto City–County AP|37.63|–120.95|California| |724927|0.53|Livermore Municipal|37.70|–121.82|California| |724930|0.54|Oakland Metropolitan Arpt|37.72|–122.22|California| |724935|0.47|Hayward Air Term|37.67|–122.12|California| |724936|0.53|Concord–Buchanan Field|38.00|–122.05|California|
170 2025 CALIFORNIA ENERGY CODE
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
SINGLE-FAMILY RESIDENTIAL BUILDINGS— MANDATORY FEATURES AND DEVICES
TABLE 150.0-D—INFILTRATION EFFECTIVENESS WEATHER AND SHIELDING FACTORS [ASHRAE 62.2:TABLE B1]—continued Col2 Col3 Col4 Col5 Col6 TMY3 WSF WEATHER STATION LATITUDE LONGITUDE STATE 724940 0.60 San Francisco Intl AP 37.62 –122.40 California 724945 0.48 San Jose Intl AP 37.37 –121.93 California 724955 0.55 Napa Co. Airport 38.22 –122.28 California 724957 0.49 Santa Rosa (AWOS) 38.52 –122.82 California 725845 0.44 Blue Canyon AP 39.30 –120.72 California 725846 0.66 Truckee–Tahoe 39.32 –120.13 California 725847 0.64 South Lake Tahoe 38.90 –120.00 California 725905 0.47 Ukiah Municipal AP 39.13 –123.20 California 725910 0.50 Red Bluff Municipal Arpt 40.15 –122.25 California 725920 0.47 Redding Municipal Arpt 40.52 –122.32 California 725945 0.56 Arcata Airport 40.98 –124.10 California 725946 0.
Frequently asked questions
Who determines how thick the barrier must be?
A certified medical physicist or other qualified expert must specify the type, location and amount of shielding; the code requires these specifications be incorporated into the construction documents. § 1224.18.1.1 and Standard 12‑31C‑1 are the technical references.
Can the operator stand behind a partial partition instead of a full room or booth?
Only if that partition functions as a protective barrier that will intercept the useful beam and any radiation scattered only once. The code lists a separate room, protected booth or behind a shield as acceptable options in § 3103C.1; whether a partial partition suffices depends on the shielding calculation.
Is a mirror or CCTV acceptable instead of a lead window?
For certain equipment (see § 3104C.2 for equipment above 50 kVp) the control station may use a mirror system or closed‑circuit television as an alternative to a viewing window; confirm which alternatives are permitted for the specific equipment and energy.
Who can grant a variance from the shielding standard?
The Department of Health Services is the only agency that may grant a variance or exception to the radiation shielding standards referenced by the code. § 3102C.
Does § 3103C.1 give specific lead thicknesses?
No. § 3103C.1 specifies placement and performance (intercept useful beam and single scatter) but does not supply numeric thicknesses; the required amounts come from shielding calculations using Standard 12‑31C‑1 and the certified physicist’s specification.
More in California Referenced Standards Code
- Administration and scope — CRSC Chapter 12 overview
- Air filter standards (Chapter 12‑71)
- Building and facility access / accessibility standards (Chapters 12‑11A, 12‑11B)
- Engineering regulations — quality and design of construction materials (12‑16 series)
- Exits and means of egress (Chapters 12‑10 series)
- Protective signaling systems and detectors (Chapters 12‑72‑1, ‑2, ‑3)
- Radiation shielding standards (Chapter 12‑31C)
- Referenced standards index / cross‑reference table (Part 12 listing of referenced standards)
- Releasing systems for security bars (egress-release standards)
- Standards for insulating materials (Chapter 12‑13)
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