CRSC · California Referenced Standards Code

Which NCRP reports are mandatory for shielding design?

Q: Which NCRP report do I use for a dental operatory?

Use NCRP Report No. 35 ; dental X‑ray shielding must comply with its mandatory standards/appendices under § 12-31C-101 .

Q: What if my X‑ray tube is used for therapeutic beams above diagnostic energies?

If the medical photon energy is within up to 10 MeV , apply NCRP Report No. 49 (mandatory per § 12-31C-101 ). If you have a particle accelerator or sources in the 0.1–100 MeV range, NCRP Report No. 51 applies. § 12-31C-101 requires the listed reports.

Q: Can I substitute a different standard (e.g., international guidance) instead of these NCRP reports?

Not for the mandatory aspects referenced in § 12-31C-101 . These three NCRP reports and their mandatory standards/appendices are the required references. For any substitution or variance, follow the Department of Health Services process (see Building Code § 3102C). file

Q: What if my source energy falls into more than one report’s scope?

Because § 12-31C-101 lists multiple mandatory reports that may overlap in scope, consult the report(s) whose scope covers your equipment and document which mandatory sections/appendices you relied on. When in doubt, consult both mandatory reports and the Department of Health Services for interpretation. file

If a room houses X‑ray or accelerator equipment in California, its shielding design must follow the mandatory NCRP reports listed in **§ 12-31C-101**: Report 35 for dental, Report 49 for medical X‑rays up to 10 MeV, and Report 51 for particle accelerators 0.1–100 MeV.

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Last reviewed: July 6, 2026

What the code requires — plain English

All radiation shielding barriers used in rooms and enclosures that house radiation machines must follow the mandatory standards and appendices of three specific NCRP reports listed in the California Referenced Standards Code. The controlling provision is § 12-31C-101 — those reports are required for compliance.

The single most important rule: Designs for shielding must follow the mandatory standards and appendices of NCRP Reports 35, 49 and 51 as required by § 12-31C-101.

Requirements in detail

Which NCRP reports are mandatory

NCRP Report No. 35 — “Dental X‑RAY Protection.” Use this report for dental X‑ray operatory shielding guidance. § 12-31C-101.
NCRP Report No. 49 — “Structural Shielding Design and Evaluation for Medical use of X‑rays and Gamma Rays of Energies up to 10 MeV.” Use this for medical X‑ray and gamma installations whose energies are up to 10 MeV. § 12-31C-101.
NCRP Report No. 51 — “Radiation Protection Design Guidelines for 0.1–100 MeV Particle Accelerator Facilities.” Use this for particle accelerator facilities in the 0.1–100 MeV energy range. § 12-31C-101.

Decision table — which report to use

NCRP Report	Applicable equipment / facility	Key scope or threshold	When mandatory	Code Reference
Report No. 35	Dental X‑ray operatories	Dental X‑ray protection guidance	Always required for dental X‑ray shielding	§ 12-31C-101
Report No. 49	Medical X‑ray & gamma rooms	Up to 10 MeV photon energies	Required for medical X‑ray/gamma shielding within its scope	§ 12-31C-101
Report No. 51	Particle accelerator facilities	0.1–100 MeV particle accelerators	Required for accelerator facility shielding in its scope	§ 12-31C-101

How to apply the requirement

The code does not permit arbitrary substitution — the listed NCRP reports and their mandatory standards/appendices are the references you must use for shielding design where they apply. § 12-31C-101.
If an installation or radiation source falls inside the scope of more than one report (e.g., an accelerator used for medical therapy whose energies fall near both Report 49 and Report 51 scopes), both reports listed in § 12-31C-101 are mandatory references and should be consulted.

Exceptions & special cases

The text of § 12-31C-101 itself does not list exceptions to the requirement to use these NCRP reports; it states the reports are mandatory. § 12-31C-101.
Administrative variances or exceptions to the referenced standards are not granted by the CRSC text in § 12-31C-101. Note: the California Building Code Chapter that references these CRSC requirements indicates the Department of Health Services is the agency with authority to grant a variance to these standards; consult § 3102C of the California Building Code for variance/administration follow‑up.

If you need to claim an exception or variance, follow the Department of Health Services process (see the Building Code cross‑reference) — do not assume an alternative standard replaces the NCRP reports cited in § 12-31C-101.

Common mistakes

Assuming any NRC/NCRP publication is acceptable — only Report Nos. 35, 49 and 51 are mandated by § 12-31C-101.
Using an older or non‑applicable NCRP report in place of the listed reports without documentation or approval. The mandatory reports and their appendices in § 12-31C-101 must be the bases for design.
Ignoring scope overlap (e.g., accelerator vs. medical machine energies). When scope overlaps, consult the applicable mandatory reports from § 12-31C-101 rather than choosing one arbitrarily.
Failing to note/report in design documents which NCRP report(s) were used. The plans and calculations should explicitly cite the applicable NCRP report(s) required by § 12-31C-101.

Worked example — applying the rule (concrete scenario)

Scenario: A clinic is planning two adjacent rooms:

Room A: two dental intraoral units and a panoramic dental unit.
Room B: a new medical radiography room with a general radiographic X‑ray system operating at 150 kVp (diagnostic radiography).

Which mandatory NCRP reports apply?

For Room A (dental): follow NCRP Report No. 35 for dental X‑ray protection; this is mandatory under § 12-31C-101.
For Room B (medical diagnostic at 150 kVp): this is a medical X‑ray application with photon energies well below 10 MeV, so NCRP Report No. 49 is the mandatory report to use for structural shielding design under § 12-31C-101.

How to document on plans:

In the shielding design report and on construction drawings, state: “Shielding design based on mandatory standards/appendices of NCRP Report No. 35 (dental) and NCRP Report No. 49 (medical X‑ray ≤10 MeV) as required by § 12-31C-101.”

(If the clinic later installs an electron accelerator or higher‑energy therapy equipment, identify the energy and then apply NCRP Report No. 51 for accelerators in the 0.1–100 MeV range — § 12-31C-101.)

Related provisions

§ 12-31C-101 (Radiation shielding barriers must comply with NCRP Reports 35, 49 and 51.)
California Building Code — § 3102C (Cross‑reference: states that shielding barriers must meet the requirements of Section 12-31C-101 and identifies the Department of Health Services as the agency that may grant a variance).

Note: The CRSC text provided contains § 12-31C-101 as the controlling requirement; no other CRSC shielding sections were located in the supplied files.

Code references

Grounded in the retrieved California Referenced Standards Code — click a citation to read the verbatim passage:

CRSC § 436.5. High relevance — show source text
DEPARTMENT OF HEALTH SERVICES

Authority: Sections 102, 208 and 25811.

Reference: Sections 102, 208 and 436.5.

ALL HEALING ARTS X-RAY INSTALLATIONS

Sec. 12-31C-101. All radiation shielding barriers in rooms and enclosures housing radiation machines shall comply with the mandatory standards and appendices in Report No. 35, “Dental X-RAY Protection”; Report 49, “Structural Shielding Design and Evaluation for Medical use of X-rays and Gamma Rays of Energies up to 10 MeV”; and Report No. 51, “Radiation Protection Design Guidelines for 0.1-100 MeV Particle Accelerator Facilities.” Published by the National Council on Radiation Protection and Measurements, 7910 Woodmont Avenue, Bethesda, Maryland 20814.

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12-71 AIR FILTERS

STANDARD 12-71-1

STATE FIRE MARSHAL

DESCRIPTION OF TEST APPARATUS, METHOD AND CLASSIFICATION REQUIREMENTS FOR AIR FILTERS

Sec. 12-71-100.

(a) Test apparatus.
1. The test duct, made of M.S. gage galvanized sheet metal reinforced with angle irons, is 21 inches square (13 548 mm [2] ) and 13 [1] / 2 feet (4114 mm) long.
2. One end of the duct is tapered to the discharge of a variable-speed blower and the other end is open to discharge. A metal filter frame is provided near the middle of the length of the duct to receive one 20 by 20 inches (508 mm by 508 mm) (nominal) filter unit. Two tightfitting doors, located to permit access to the filter frame, are each provided with a mica window to permit observation of both faces of the filter and conditions in the duct downstream from the filter.
3. Two 1-inch (25 mm) pipe elbows, about 18 inches (457 mm) from the base of the test filter, form gas burner outlets adjusted to provide yellow, wavering flames. The burners consume approximately 4 cubic feet (approximately 1,000 Btu/cubic feet) of gas per minute.
4. With the filter in place the air velocity is adjusted to approximately 200 linear feet per minute as measured at the discharge end of the duct by an Alnor Velometer Anemometer.
(b) Test method.
1. Filters are tested clean, that is, unused. The flames are applied for 3 minutes during which time observations are made of both faces of the filter as to the downstream travel of flame or sparks and the density, duration and character of the products of combustion.
CRSC § 12-16 High relevance — show source text
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

Authority: Sections 102, 208 and 25811.

Reference: Sections 102, 208 and 436.5.

ALL HEALING ARTS X-RAY INSTALLATIONS

Sec. 12-31C-101. All radiation shielding barriers in rooms and enclosures housing radiation machines shall comply with the mandatory standards and appendices in Report No. 35, “Dental X-RAY Protection”; Report 49, “Structural Shielding Design and Evaluation for Medical use of X-rays and Gamma Rays of Energies up to 10 MeV”; and Report No. 51, “Radiation Protection Design Guidelines for 0.1-100 MeV Particle Accelerator Facilities.” Published by the National Council on Radiation Protection and Measurements, 7910 Woodmont Avenue, Bethesda, Maryland 20814.

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12-71 AIR FILTERS

STANDARD 12-71-1

STATE FIRE MARSHAL

DESCRIPTION OF TEST APPARATUS, METHOD AND CLASSIFICATION REQUIREMENTS FOR AIR FILTERS

Sec. 12-71-100.

(a) Test apparatus.
1. The test duct, made of M.S. gage galvanized sheet metal reinforced with angle irons, is 21 inches square (13 548 mm [2] ) and 13 [1] / 2 feet (4114 mm) long.
CRSC § 1206.2 High relevance — show source text
1206.2, 1206.2.1

E96/E96M—21: Standard Test Methods for Gravimetric Determination of Water Vapor Transmission Rate of Materials

202, 1202.3, 1404.3

E108—20a: Standard Test Methods for Fire Tests of Roof Coverings

1505.1, 2603.6, 2610.2, 2610.3

E119—20: Standard Test Methods for Fire Tests of Building Construction and Materials

705.8.5, 703.2.1.1, 703.2.1.3, 703.2.1.4, 703.2.1.5, 703.2.2, 703.4, 703.6, 704.11, 705.8, 707.6, 712.1.13.2, 714.4.1, 714.5.1, 715.3, 715.4, 715.4.1, Table 716.1(1), Table 716.1(2), Table 716.1(3), 716.1.2.3, 716.2.5.1.1, 716.2.5.4, 716.3.2.1.1, 717.3.1, 717.5.2, 717.5.3, 717.6.1, 717.6.2, Table 721.1(1), 2103.1, 2603.5.1

E136—2022: Standard Test Method for Assessing Combustibility of Materials Using a Vertical Tube Furnace at 750 Degrees C

703.3.1

E283/E283M—19: Standard Test Method for Determining Rate of Air Leakage Through Exterior Windows, Curtain Walls, and Doors Under Specified Pressure Differences Across the Specimen

202

E330/E330M—14(2021): Test Method for Structural Performance of Exterior Windows, Doors, Skylights and Curtain Walls by Uniform Static Air Pressure Difference

1709.5.2, 1709.5.2.1, 1709.5.3.1

E331—2000(2016): Standard Test Method for Water Penetration of Exterior Windows, Skylights, Doors and Curtain Walls by Uniform Static Air Pressure Difference

1402.2, 1403.2

E336—20: Standard Test Method for Measurement of Airborne Sound Attenuation between Rooms in Buildings

1206.2

E492—2009(2016)E1: Test Method for Laboratory Measurement of Impact Sound Transmission Through Floor-Ceiling Assemblies Using the Tapping Machine

1206.3

E580/E580M—22: Standard Practice for Installation of Ceiling Suspension Systems for Acoustical Tile and Lay-in Panels in Areas Subject to Earthquake Ground Motions

1617.12.13, 1617A.1.21

E605/E605M—19: Test Method for Thickness and Density of Sprayed Fire-Resistive Material (SFRM) Applied to Structural Members

1705.15.4.1, 1705.15.4.2, 1705.15.4.5, 1705.15.5

E648—2017A: Standard Test Method for Critical Radiant Flux of Floor-Covering Systems Using a Radiant Heat Energy Source

CRSC § 03-25 High relevance — show source text

Table 7 Codes for Subsurface Round, Single-Phase With 3 Secondary Bushings, Neutral May be Permanently Grounded. Use to Supply Single-Phase Load. (reference Document 035313 and Spec. 91) − Self-Protected, Stainless Steel

kVA	4160/7200Y 240/120 V 4 Primary Bushings	4,160GrdY/2,400 240/120 V 2 Primary Bushings	Col4
kVA	No Switch	No Switch	With Single-Phase Switch
100	2623711, E	2621201, E	2621431, E

(See Table 36 on Page 14 for other single-phase round transformers.)

1 Current standard design and may be purchased. 2

4 Use for replacement only and may be purchased. E Included in Emergency Stock 5

062111 Page 6 of 26 Rev. #27: 03-25-22

UG-1: Transformers Greenbook Application of Underground Distribution Transformers EDM

Single-Phase, Subsurface, for New Construction (continued)

Table 8 Codes for Subsurface Subway-LB, Single-Phase, (reference Document 072139 and Spec. 91) − Self-Protected, Stainless Steel

kVA	2,400/4,160Y-120/240 3 Primary Bushings 4 Secondary Bushings	12,000/20,780Y − 120/240	Col4
kVA	2,400/4,160Y-120/240 3 Primary Bushings 4 Secondary Bushings	2 Primary Bushings 4 Secondary Bushings	3 Primary Bushings 4 Secondary Bushings
50	2613881, E	2613841	2613911
100	2613891	2613851, E	2613921, E
167	2613901, E	2613861	2613931
250	−	2613871, E	2613941, E

Three-Phase, Pad-Mount, for New Construction

Table 9 Codes for Duplex-Style DF, Three-Phase, Pad-Mount, No Loop Switch, With Transformer Switch With 6 Primary Bushings and 4 Secondary Bushings Including the Insulated Neutral (reference Document 064307 and Spec. 86) − Self-Protected

California Referenced Standards Code High relevance — show source text
|100 psf|1 hr
23 min|||7|1, 2|11/3| |F/C-4-RC-9|4″|4″ deep (4370 psi);1/4″ reinforcement bars
at 6″ pitch with3/4″ cover;1/4″ main rein-
forcement bars at 4″ pitch perpendicular
with1/2″ cover; 13′1″ span restrained.|150 psf|2 hrs|||7|1, 3|2| |F/C-4-RC-10|4″|4″ thick (5140 psi) deck;1/4″ reinforce-
ment bars at 71/2″ pitch with7/8″ cover;3/8″
main reinforcement bars at 33/4″ pitch
perpendicular with1/2″ cover; 13′1″ span
restrained.|140 psf|1 hr
16 min|||7|1, 5|11/4| |F/C-4-RC-11|4″|4″ thick (4000 psi) concrete deck;
3″ × 11/2″ × 4 lbs R.S.J.; 2′6″ C.R.S.; flush
with top surface; 4″ × 6″ x 13 SWG mesh
reinforcement 1″ from bottom of slab; 6′6″
span restrained.|150 psf|2 hrs|||7|1, 3|2| |F/C-4-RC-12|4″|4″ deep (2380 psi) concrete deck;
3″ × 11/2″ × 4 lbs R.S.J.; 2′6″ C.R.S.; flush
with top surface; 4″ × 6″ x 13 SWG mesh
reinforcement 1″ from bottom surface;
6′6″ span restrained.|150 psf|1 hr
3 min|||7|1, 2|1| |F/C-4-RC-13|41/2″|41/2″ thick (5200 psi) deck;1/4″ reinforce-
ment bars at 71/4″ pitch with7/8″ cover;3/8″
main reinforcement bars at 33/4″ pitch
perpendicular with1/2″ cover; 13′1″ span
restrained.|140 psf|2 hrs|||7|1, 3|2| |F/C-4-RC-14|41/2″|41/2″ deep (2525 psi) concrete deck;1/4″
reinforcement bars at 71/2″ pitch with7/8″
cover;3/8″ main reinforcement bars at
33/8″ pitch perpendicular with1/2″ cover;
13′1″ span restrained.|150 psf|42 min|||7|1, 5|2/3| |F/C-4-RC-15|41/2″|41/2″ deep (4830 psi) concrete deck;
11/2″ × No.
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 § 12-16 High relevance — show source text

CHAPTER 12-16-1 ENGINEERING REGULATIONS—QUALITY

AND DESIGN OF THE MATERIALS OF

CONSTRUCTION . . . . . . . . . . . . . . . . . . . 101

CHAPTER 12-16-2 ENGINEERING REGULATIONS—QUALITY

AND DESIGN OF THE MATERIALS OF

CONSTRUCTION . . . . . . . . . . . . . . . . . . . 103

CHAPTER 12-31C RADIATION SHIELDING STANDARDS . . 105

CHAPTER 12-71 AIR FILTERS. . . . . . . . . . . . . . . . . . . . . . . 107

CHAPTER 12-72-1 PROTECTIVE SIGNALING SYSTEMS . . . 109

CHAPTER 12-72-2 PROTECTIVE SIGNALING SYSTEMS . . . 123

CHAPTER 12-72-3 PROTECTIVE SIGNALING SYSTEMS . . . 133

HISTORY NOTE APPENDIX . . . . . . . . . . . . . . . . . . . . . . . . . . . 157

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PART 12 CROSS REFERENCE TABLE

(Cross reference table is nonregulatory, intended only as an aid to the code user.)

PART 12 STANDARD	SUBJECT	ADOPTING AGENCY	ASSOCIATED TITLE 24 BUILDING STANDARD
Chapter 12-3	Releasing systems for security bars in dwellings	SFM	Part 2, Sections 1031.2.1, 1031.6, 1032.7 Part 2.5, Sections R319.1.1 and R319.4.4 Part 9, Sections 1031.2.1, 1031.6, 1032.7 Appendix 4 Section 452.1.5 and Title 19 provisions 4.1, 4.2, 4.3, 4.4, 4.5, 4.6 reprinted in Part 9 Part 10, Section 505.4
Chapter 12-4A	Laboratory animal quarters standards	DPH	Part 2, Section 1236
Chapter 12-4-1	Stage and Platforms	SFM	Part 2, Sections 410.2.7, 410.2.7.1, 410.2.7.2 Part 9, Sections 105.6.51, 4809
Chapter 12-7-1	Fire-resistive standards.

CRSC § 12-16 High 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 § 1009.12 High relevance — show source text
Emergency exit and panic hardware.
|SFM|Part 9, Section 1009.12| |Chapter 12-11A,
12-11B|Detectable warning products and directional
surfaces|DSA|Part 2, Sections 1112A.9, 1116A.5, 11B-247,
11B-406.5.12, 11B-705, 11B-810.5.2| |Chapter 12-12|Reserved||| |Chapter 12-13|Standards for insulating material|CA/SFM|Part 2.5, Section R302.10.1
Part 6, Section 110.8
Part 9, Section 720, Table 721.1(1)
Part 11, Section A5.504.4.8| |Chapter 12-16-1|California standard for earthquake-actuated
automatic gas shutoff systems|DSA|Part 2, Chapters 16 and 16A
Part 5, Section 1211.8| |Chapter 12-16-2|California standard for residential excess flow
actuated automatic gas shutoff valves|DSA|Part 5, Section 1209.1| |Chapter 12-31C|Radiation shielding|DPH|Part 2, Section 3102C| |Chapter 12-71|Air filters|SFM|Part 4, Sections 401.2, 509.2.3, 509.2.3.4
Part 6, Section 120.1| |Chapter 12-72-1|Protective signaling systems.
Standard test procedures.|SFM|| |Chapter 12-72-2|Protective signaling systems. Single-and
multiple-station fire alarm devices
mechanically operated type.|SFM|| |Chapter 12-72-3|Protective signaling systems. Smoke detectors,
combustion products type.|SFM||

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12-1 ADMINISTRATION

RESERVED

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12-3 RELEASING SYSTEMS FOR SECURITY BARS IN DWELLINGS

(This standard includes provisions of Underwriters Laboratories Subject 2326, Appendix B, dated December 17, 1999, reprinted with their permission.)

INTRODUCTION

SECTION 12-3-1—SCOPE

12-3-1.1 These requirements cover releasing systems for bars, grilles, mesh, glazing or other items intended to provide security at doors and windows required for emergency escape from dwelling units. When actuated by the occupant, the system allows the obstructions over the door or window to be moved so occupants can escape in the event of an emergency.

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- CG	SFM	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- CG	SFM	1	2	1/AC	AC	SS	SS/CC	1	1R	2	3	4	5	6	6	6	6	6	6	6	6	6
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Adopt entire chapter as amended (amended sections listed below)
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Chapter / 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.

2025 CALIFORNIA BUILDING CODE 31C-1

on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.

31C-2 2025 CALIFORNIA BUILDING CODE

on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.

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 § 308.5 Medium relevance — show source text
For Group I-3 Occupancies see Section 308.5 of the California Building Code._

[MP] RETURN AIR. Air removed from an approved conditioned space or location and recirculated or exhausted.

[RB] RIDGE. With respect to topographic wind effects, an elongated crest of a hill characterized by strong relief in two directions.

[MP] RISER (PLUMBING). A water pipe that extends vertically one full story or more to convey water to branches or to a group of fixtures.

[RB] RISER (STAIR). The vertical component of a step or stair.

[RB] ROOF ASSEMBLY. A system designed to provide weather protection and resistance to design loads. The system consists of a roof covering and roof deck or a single component serving as both the roof covering and the roof deck. A roof assembly can include an underlayment, thermal barrier, ignition barrier, insulation or a vapor retarder.

[RB] ROOF COATING. A fluid-applied, adhered coating used for roof maintenance or roof repair, or as a component of a roof covering system or roof assembly.

[RB] ROOF COVERING. The covering applied to the roof deck for weather resistance, fire classification or appearance.

[RB] ROOF COVERING SYSTEM. See “Roof assembly.”

[RB] ROOF DECK. The flat or sloped surface not including its supporting members or vertical supports.

[RB] ROOF RECOVER. The process of installing an additional roof covering over an existing roof covering without removing the existing roof covering.

[RB] ROOF REPAIR. Reconstruction or renewal of any part of an existing roof for the purposes of its maintenance.

[RB] ROOF REPLACEMENT. The process of removing the existing roof covering, repairing any damaged substrate and installing a new roof covering.

[MP] ROOM HEATER. A free-standing heating appliance installed in the space being heated and not connected to ducts.

[MP] ROUGH-IN. The installation of the parts of the plumbing system that must be completed prior to the installation of fixtures. This includes DWV, water supply and built-in fixture supports.

[RB] RUNNING BOND. The placement of masonry units such that head joints in successive courses are horizontally offset not less than one-quarter the unit length.

[MP] SANITARY SEWER. A sewer that carries sewage and excludes storm, surface and groundwater.

[RB] SCUPPER. An opening in a wall or parapet that allows water to drain from a roof.

[RB] SEISMIC DESIGN CATEGORY (SDC). A classification assigned to a structure based on its occupancy and the severity of the design earthquake ground motion at the site.

[MP] SEPTIC TANK. A watertight receptor that receives the discharge of a building sanitary drainage system and is constructed so as to separate solids from the liquid, digest organic matter through a period of detention, and allow the liquids to discharge into the soil outside of the tank through a system of open joint or perforated piping or a seepage pit.

[MP] SEWAGE. Any liquid waste containing animal matter, vegetable matter or other impurity in suspension or solution.

[MP] SEWAGE PUMP. A permanently installed mechanical device for removing sewage or liquid waste from a sump.

[RB] SHALL. The term, where used in the code, is construed as mandatory.
CRSC § 31B-22 Medium relevance — show source text
3162B Anti-Entrapment Devices and Systems . . . . . . . . . . 31B-22

CHAPTER 31C RADIATION . . . . . . . . . . . . . . . . . . . . . . . . . .31C-1

3101C Scope. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31C-3

3102C Radiation Shielding Barriers . . . . . . . . . . . . . . . . . . . . . 31C-3

3103C Medical Radiographic and Photofluorographic Installations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31C-3

3104C Medical Therapeutic X-Ray Installations. . . . . . . . . . 31C-3

CHAPTER 31D FOOD ESTABLISHMENTS. . . . . . . . . . . . . . .31D-1

3101D Scope. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31D-3

3102D Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31D-3

3103D Buildings and Structures. . . . . . . . . . . . . . . . . . . . . . . . . 31D-3

CHAPTER 31E RESERVED. . . . . . . . . . . . . . . . . . . . . . . . . . .31E-1

CHAPTER 31F MARINE OIL TERMINALS . . . . . . . . . . . . . . .31F-1

3101F Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31F-3

3102F Audit and Inspection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31F-6

3103F Structural Loading Criteria . . . . . . . . . . . . . . . . . . . . . 31F-19

3104F Seismic Analysis and Structural Performance. . . . 31F-34

3105F Mooring and Berthing Analysis and Design . . . . . . 31F-48

3106F Geotechnical Hazards and Foundations . . . . . . . . . 31F-55

Frequently asked questions

Which NCRP report do I use for a dental operatory?

Use NCRP Report No. 35; dental X‑ray shielding must comply with its mandatory standards/appendices under § 12-31C-101.

What if my X‑ray tube is used for therapeutic beams above diagnostic energies?

If the medical photon energy is within up to 10 MeV, apply NCRP Report No. 49 (mandatory per § 12-31C-101). If you have a particle accelerator or sources in the 0.1–100 MeV range, NCRP Report No. 51 applies. § 12-31C-101 requires the listed reports.

Can I substitute a different standard (e.g., international guidance) instead of these NCRP reports?

Not for the mandatory aspects referenced in § 12-31C-101. These three NCRP reports and their mandatory standards/appendices are the required references. For any substitution or variance, follow the Department of Health Services process (see Building Code § 3102C). file

Do I have to cite the NCRP report(s) on the construction drawings?

Yes — the code requires the designs to comply with the mandatory standards/appendices in the listed NCRP reports, so explicitly citing which report(s) and editions were used on the drawings and calculations is standard practice and helps demonstrate compliance with § 12-31C-101.

What if my source energy falls into more than one report’s scope?

Because § 12-31C-101 lists multiple mandatory reports that may overlap in scope, consult the report(s) whose scope covers your equipment and document which mandatory sections/appendices you relied on. When in doubt, consult both mandatory reports and the Department of Health Services for interpretation. file

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Scope and mandatory referenced standards

California Referenced Standards Code

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Code references

12-71 AIR FILTERS

12-31C RADIATION SHIELDING STANDARDS

12-71 AIR FILTERS

31C [DPH] RADIATION

12-16-1 ENGINEERING REGULATIONS—QUALITY AND

12-16-2 ENGINEERING REGULATIONS—QUALITY AND

12-31C RADIATION SHIELDING STANDARDS

12-1 ADMINISTRATION

12-3 RELEASING SYSTEMS FOR SECURITY BARS IN DWELLINGS

31C [DPH] RADIATION

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