California Code of Regulations › Title 8 - Industrial Relations › Division 1 - Department of Industrial Relations › Chapter 4 - Division of Industrial Safety › Subchapter 4 - Construction Safety Orders › Article 4 - Dusts, Fumes, Mists, Vapors, and Gases › Section 1532.3 - Occupational Exposures to Respirable Crystalline Silica

Current through Register 2024 Notice Reg. No. 28, July 12, 2024
(a) Scope and application. This section
					 applies to all occupational exposures to respirable crystalline silica in
					 construction work, except where employee exposure will remain below 25
					 micrograms per cubic meter of air (25 µg/m3)
					 as an 8-hour time-weighted average (TWA) under any foreseeable
					 conditions.
(b) Definitions. For
					 the purposes of this section the following definitions apply:
Action Level means a concentration of airborne respirable
						crystalline silica of 25 µg/m3, calculated as
						an 8-hour TWA.
Chief means the Chief of the Division of Occupational
						Safety and Health, or designee.
Director means the Director of the National Institute for
						Occupational Safety and Health (NIOSH), U.S. Department of Health and Human
						Services, or designee.
Competent Person means an individual who is capable of
						identifying existing and foreseeable respirable crystalline silica hazards in
						the workplace and who has authorization to take prompt corrective measures to
						eliminate or minimize them. The competent person must have the knowledge and
						ability necessary to fulfill the responsibilities set forth in subsection
						(g).
Employee Exposure means the exposure to airborne
						respirable crystalline silica that would occur if the employee were not using a
						respirator.
High-efficiency Particulate Air (HEPA) Filter means a
						filter that is at least 99.97 percent efficient in removing mono-dispersed
						particles of 0.3 micrometers in diameter.
Objective Data means information, such as air monitoring
						data from industry-wide surveys or calculations based on the composition of a
						substance, demonstrating employee exposure to respirable crystalline silica
						associated with a particular product or material or a specific process, task,
						or activity. The data must reflect workplace conditions closely resembling or
						with a higher exposure potential than the processes, types of material, control
						methods, work practices, and environmental conditions in the employer's current
						operations.
Physician or Other Licensed Health Care Professional
						(PLHCP) means an individual whose legally permitted scope of practice (i.e.,
						license, registration, or certification) allows him or her to independently
						provide or be delegated the responsibility to provide some or all of the
						particular health care services required by subsection (h).
Respirable Crystalline Silica means quartz, cristobalite,
						and/or tridymite contained in airborne particles that are determined to be
						respirable by a sampling device designed to meet the characteristics for
						respirable-particle-size-selective samplers specified in the International
						Organization for Standardization (ISO) 7708:1995: Air Quality--Particle Size
						Fraction Definitions for Health-Related Sampling.
Specialist means an American Board Certified Specialist
						in Pulmonary Disease or an American Board Certified Specialist in Occupational
						Medicine.
This Section means this respirable crystalline silica
						standard, Section
						1532.3.
(c) Specified exposure control methods.
(1) For each employee engaged in a task
					 identified on Table 1, the employer shall fully and properly implement the
					 engineering controls, work practices, and respiratory protection specified for
					 the task on Table 1, unless the employer assesses and limits the exposure of
					 the employee to respirable crystalline silica in accordance with subsection
					 (d).
Table 1--Specified Exposure
								  Control Methods When Working With Materials Containing Crystalline
								  Silica
Required respiratory protection and
								  minimum assigned protection factor (APF)
Equipment/task
Engineering and work practice
								  control methods
[LESS THAN EQUAL TO] 4
								  hours/shift
>4
								  hours/shift
(i) Stationary masonry saws
Use saw equipped with integrated water delivery
								  system that continuously feeds water to the blade
None
None.
Operate and maintain tool in accordance with
								  manufacturer's instructions to minimize dust emissions
(ii) Handheld power saws (any blade
								  diameter)
Use saw equipped with integrated water delivery
								  system that continuously feeds water to the blade
Operate and maintain tool in accordance with
								  manufacturer's instructions to minimize dust emissions:
--When used outdoors
None
APF 10.
--When used indoors or in an enclosed
								  area
APF 10
APF 10.
(iii) Handheld power saws for cutting
								  fiber-cement board (with blade diameter of 8 inches or less)
For tasks performed outdoors only: Use saw
								  equipped with commercially available dust collection system
None
None.
Operate and maintain tool in accordance with
								  manufacturer's instructions to minimize dust emissions
Dust collector must provide the air flow
								  recommended by the tool manufacturer, or greater, and have a filter with 99% or
								  greater efficiency
(iv) Walk-behind saws
Use saw equipped with integrated water delivery
								  system that continuously feeds water to the blade
Operate and maintain tool in accordance with
								  manufacturer's instructions to minimize dust emissions:
--When used outdoors
None
None.
--When used indoors or in an enclosed
								  area
APF 10
APF 10.
(v) Drivable saws
For tasks performed outdoors
								  only:
Use saw equipped with integrated water delivery
								  system that continuously feeds water to the blade
None
None.
Operate and maintain tool in accordance with
								  manufacturer's instructions to minimize dust emissions
(vi) Rig-mounted core saws or
								  drills
Use tool equipped with integrated water delivery
								  system that supplies water to cutting surface
None
None.
Operate and maintain tool in accordance with
								  manufacturer's instructions to minimize dust emissions
(vii) Handheld and stand-mounted drills
								  (including impact and rotary hammer drills)
Use drill equipped with commercially available
								  shroud or cowling with dust collection system
None
None.
Operate and maintain tool in accordance with
								  manufacturer's instructions to minimize dust emissions
Dust collector must provide the air flow
								  recommended by the tool manufacturer, or greater, and have a filter with 99% or
								  greater efficiency and a filter-cleaning mechanism
Use a HEPA-filtered vacuum when cleaning
								  holes
(viii) Dowel drilling rigs for
								  concrete
For tasks performed outdoors
								  only:
Use shroud around drill bit with a dust
								  collection system. Dust collector must have a filter with 99% or greater
								  efficiency and a filter-cleaning mechanism
APF 10
APF 10.
Use a HEPA-filtered vacuum when cleaning
								  holes
(ix) Vehicle-mounted drilling rigs for rock and
								  concrete
Use dust collection system with close capture
								  hood or shroud around drill bit with a low-flow water spray to wet the dust at
								  the discharge point from the dust collector
None
None.
OR
Operate from within an enclosed cab and use water
								  for dust suppression on drill bit
None
None.
(x) Jackhammers and handheld powered chipping
								  tools
Use tool with water delivery system that supplies
								  a continuous stream or spray of water at the point of impact:
--When used outdoors
None
APF 10.
--When used indoors or in an enclosed
								  area
APF 10
APF 10.
OR
Use tool equipped with commercially available
								  shroud and dust collection system
Operate and maintain tool in accordance with
								  manufacturer's instructions to minimize dust emissions
Dust collector must provide the air flow
								  recommended by the tool manufacturer, or greater, and have a filter with 99% or
								  greater efficiency and a filter-cleaning mechanism:
--When used outdoors
None
APF 10.
--When used indoors or in an enclosed
								  area
APF 10
APF 10.
(xi) Handheld grinders for mortar removal
								  (
i.e.
, tuckpointing)
Use grinder equipped with commercially available
								  shroud and dust collection system
APF 10
APF 25.
Operate and maintain tool in accordance with
								  manufacturer's instructions to minimize dust emissions
Dust collector must provide 25 cubic feet per
								  minute (cfm) or greater of airflow per inch of wheel diameter and have a filter
								  with 99% or greater efficiency and a cyclonic pre-separator or filter-cleaning
								  mechanism
(xii) Handheld grinders for uses other than
								  mortar removal
For tasks performed outdoors only: Use grinder
								  equipped with integrated water delivery system that continuously feeds water to
								  the grinding surface
None
None.
Operate and maintain tool in accordance with
								  manufacturer's instructions to minimize dust emissions
OR
Use grinder equipped with commercially available
								  shroud and dust collection system
Operate and maintain tool in accordance with
								  manufacturer's instructions to minimize dust emissions
Dust collector must provide 25 cubic feet per
								  minute (cfm) or greater of airflow per inch of wheel diameter and have a filter
								  with 99% or greater efficiency and a cyclonic pre-separator or filter-cleaning
								  mechanism:
--When used outdoors
None
None.
--When used indoors or in an enclosed
								  area
None
APF 10.
(xiii) Walk-behind milling machines and floor
								  grinders
Use machine equipped with integrated water
								  delivery system that continuously feeds water to the cutting
								  surface
None
None.
Operate and maintain tool in accordance with
								  manufacturer's instructions to minimize dust emissions
OR
Use machine equipped with dust collection system
								  recommended by the manufacturer
None
None.
Operate and maintain tool in accordance with
								  manufacturer's instructions to minimize dust emissions
Dust collector must provide the air flow
								  recommended by the manufacturer, or greater, and have a filter with 99% or
								  greater efficiency and a filter-cleaning mechanism
When used indoors or in an enclosed area, use a
								  HEPA-filtered vacuum to remove loose dust in between passes
(xiv) Small drivable milling machines (less than
								  half-lane)
Use a machine equipped with supplemental water
								  sprays designed to suppress dust. Water must be combined with a
								  surfactant
None
None.
Operate and maintain machine to minimize dust
								  emissions
(xv) Large drivable milling machines (half-lane
								  and larger)
For cuts of any depth on asphalt only: Use
								  machine equipped with exhaust ventilation on drum enclosure and supplemental
								  water sprays designed to suppress dust
None
None.
Operate and maintain machine to minimize dust
								  emissions
For cuts of four inches in depth or less on any
								  substrate:
Use machine equipped with exhaust ventilation on
								  drum enclosure and supplemental water sprays designed to suppress
								  dust
None
None.
Operate and maintain machine to minimize dust
								  emissions
OR
Use a machine equipped with supplemental water
								  spray designed to suppress dust. Water must be combined with a
								  surfactant
None
None.
Operate and maintain machine to minimize dust
								  emissions
(xvi) Crushing machines
Use equipment designed to deliver water spray or
								  mist for dust suppression at crusher and other points where dust is generated
								  (
e.g.
, hoppers, conveyers, sieves/sizing or vibrating
								  components, and discharge points)
None
None.
Operate and maintain machine in accordance with
								  manufacturer's instructions to minimize dust emissions
Use a ventilated booth that provides fresh,
								  climate-controlled air to the operator, or a remote control
								  station
(xvii) Heavy equipment and utility vehicles used
								  to abrade or fracture silica-containing materials (
e.g.
,
								  hoe-ramming, rock ripping) or used during demolition activities involving
								  silica-containing materials
Operate equipment from within an enclosed cab
								  When employees outside of the cab are engaged in the task, apply water and/or
								  dust suppressants as necessary to minimize dust emissions
None
None.
(xviii) Heavy equipment and utility vehicles for
								  tasks such as grading and excavating but not including:
Apply water and/or dust suppressants as necessary
								  to minimize dust emissions OR
None
None.
Demolishing, abrading, or fracturing
								  silica-containing materials
When the equipment operator is the only employee
								  engaged in the task, operate equipment from within an enclosed
								  cab
None
None.
(2) When implementing the control measures
					 specified in Table 1, each employer shall:
(A)
					 For tasks performed indoors or in enclosed areas, provide a means of exhaust as
					 needed to minimize the accumulation of visible airborne dust;
(B) For tasks performed using wet methods,
					 apply water at flow rates sufficient to minimize release of visible
					 dust;
(C) For measures implemented
					 that include an enclosed cab or booth, ensure that the enclosed cab or booth:
1. Is maintained as free as practicable from
					 settled dust;
2. Has door seals and
					 closing mechanisms that work properly;
3. Has gaskets and seals that are in good
					 condition and working properly;
4.
					 Is under positive pressure maintained through continuous delivery of fresh
					 air;
5. Has intake air that is
					 filtered through a filter that is 95% efficient in the 0.3-10.0 µm range
					 (
e.g.
, MERV-16 or better); and
6. Has heating and cooling
					 capabilities.
(3) Where an employee performs more than one
					 task on Table 1 during the course of a shift, and the total duration of all
					 tasks combined is more than four hours, the required respiratory protection for
					 each task is the respiratory protection specified for more than four hours per
					 shift. If the total duration of all tasks on Table 1 combined is less than four
					 hours, the required respiratory protection for each task is the respiratory
					 protection specified for less than four hours per shift.