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 16 - Control of Hazardous Substances › Article 110 - Regulated Carcinogens › Appendix A - OSHA Reference Method Mandatory

Current through Register 2024 Notice Reg. No. 28, July 12, 2024
This mandatory appendix specifies the procedure for
						  analyzing air samples for asbestos, tremolite, anthophyllite, and actinolite
						  and specifies quality control procedures that must be implemented by
						  laboratories performing the analysis. The sampling and analytical methods
						  described below represent the elements of the available monitoring methods
						  (such as appendix B to this section, the most current version of the OSHA
						  method ID-60, or the most current version of the NIOSH 7400 method) which OSHA
						  considers to be essential to achieve adequate employee exposure monitoring
						  while allowing employers to use methods that are already established within
						  their organizations. All employers who are required to conduct air monitoring
						  under subsection (d) of this section are required to utilize analytical
						  laboratories that use this procedure, or an equivalent method, for collecting
						  and analyzing samples.
Sampling and Analytical Procedure
1. The sampling medium for air samples shall be mixed
						  cellulose ester filter membranes. These shall be designated by the manufacturer
						  as suitable for asbestos, tremolite, anthophyllite, and actinolite counting.
						  See below for rejection of blanks.
2. The preferred collection device shall be the 25-mm
						  diameter cassette with an open-faced 50-mm extension cowl. The 37-mm cassette
						  may be used if necessary but only if written justification for the need to use
						  the 37-mm filter cassette accompanies the sample results in the employee's
						  exposure monitoring record. Do not reuse or reload cassettes for asbestos
						  sample collection.
3. An air flow rate between 0.5 liter/min and 2.5
						  liters/min shall be selected for the 25-mm cassette. If the 37-mm cassette is
						  used, an air flow rate between 1 liter/min and 2.5 liters/min shall be
						  selected.
4. Where possible, a sufficient air volume for each air
						  sample shall be collected to yield between 100 and 1,300 fibers per square
						  millimeter on the membrane filter. If a filter darkens in appearance or if
						  loose dust is seen on the filter, a second sample shall be started.
5. Ship the samples in a rigid container with
						  sufficient packing material to prevent dislodging the collected fibers. Packing
						  material that has a high electrostatic charge on its surface (e.g., expanded
						  polystyrene) cannot be used because such material can cause loss of fibers to
						  the sides of the cassette.
6. Calibrate each personal sampling pump before and
						  after use with a representative filter cassette installed between the pump and
						  the calibration devices.
7. Personal samples shall be taken in the "breathing
						  zone" of the employee (i.e., attached to or near the collar or lapel near the
						  worker's face).
8. Fiber counts shall be made by positive phase
						  contrast using a microscope with an 8 to 10 X eyepiece and a 40 to 45 X
						  objective for a total magnification of approximately 400 X and a numerical
						  aperture of 0.65 to 0.75. The microscope shall also be fitted with a green or
						  blue filter.
9. The microscope shall be fitted with a Walton-Beckett
						  eyepiece graticule calibrated for a field diameter of 100 micrometers (+/- 2
						  micrometers).
10. The phase-shift detection limit of the microscope
						  shall be about 3 degrees measured using the HSE phase shift test slide as
						  outlined below.
a. Place the test slide on the microscope stage and
						  center it under the phase objective.
b. Bring the blocks of grooved lines into focus.
Note:
The slide consists of seven sets of
						  grooved lines (ca. 20 grooves to each block) in descending order of visibility
						  from sets 1 to 7, seven being the least visible. The requirements for asbestos,
						  tremolite, anthophyllite, and actinolite counting are that the microscope
						  optics must resolve the grooved lines in set 3 completely, although they may
						  appear somewhat faint, and that the grooved lines in sets 6 and 7 must be
						  invisible. Sets 4 and 5 must be at least partially visible but may vary
						  slightly in visibility between microscopes. A microscope that fails to meet
						  these requirements has either too low or too high a resolution to be used for
						  asbestos, tremolite, anthophyllite, and actinolite.
c. If the image deteriorates, clean and adjust the
						  microscope optics. If the problem persists, consult the microscope
						  manufacturer.
11. Each set of samples taken will include 10 percent
						  field blanks or a minimum of 2 field blanks. These blanks must come from the
						  same lot as the filters used for sample collection. The field blank results
						  shall be averaged and subtracted from the analytical results before reporting.
						  A set consists of any sample or group of samples for which an evaluation for
						  this standard must be made. Any samples represented by a field blank having a
						  fiber count in excess of the detection limit of the method being used shall be
						  rejected.
12. The samples shall be mounted by the
						  acetone/triacetin method or a method with an equivalent index of refraction and
						  similar clarity.
13. Observe the following counting rules.
a. Count only fibers equal to or longer than 5
						  micrometers. Measure the length of curved fibers along the curve.
b. Count all particles as asbestos, tremolite,
						  anthophyllite, and actinolite that have a length-to-width ratio (aspect ratio)
						  of 3:1 or greater.
c. Fibers lying entirely within the boundary of the
						  Walton-Beckett graticule field shall receive a count of 1. Fibers crossing the
						  boundary once, having one end within the circle, shall receive the count of one
						  half ( ½ ). Do not count any fiber that crosses the graticule boundary
						  more than once. Reject and do not count any other fibers even though they may
						  be visible outside the graticule area.
d. Count bundles of fibers as one fiber unless
						  individual fibers can be identified by observing both ends of an individual
						  fiber.
e. Count enough graticule fields to yield 100 fibers.
						  Count a minimum of 20 fields; stop counting at 100 fields regardless of fiber
						  count.
14. Blind recounts shall be conducted at the rate of 10
						  percent.
Quality Control Procedures
1. Intra-laboratory program. Each laboratory and/or
						  each company with more than one microscopist counting slides shall establish a
						  statistically designed quality assurance program involving blind recounts and
						  comparisons between microscopists to monitor the variability of counting by
						  each microscopist and between microscopists. In a company with more than one
						  laboratory, the program shall include all laboratories and shall also evaluate
						  the laboratory-to-laboratory variability.
2. a. Interlaboratory program. Each laboratory
						  analyzing asbestos, tremolite, anthophyllite, and actinolite samples for
						  compliance determination shall implement an interlaboratory quality assurance
						  program that as a minimum includes participation of at least two other
						  independent laboratories. Each laboratory shall participate in round robin
						  testing at least once every 6 months with at least all the other laboratories
						  in its interlaboratory quality assurance group. Each laboratory shall submit
						  slides typical of its own work load for use in this program. The round robin
						  shall be designed and results analyzed using appropriate statistical
						  methodology.
b. All laboratories should participate in a national
						  sample testing scheme such as the Proficiency Analytical Testing Program (PAT),
						  the Asbestos Registry sponsored by the American Industrial Hygiene Association
						  (AIHA).
3. All individuals performing asbestos, tremolite,
						  anthophyllite, and actinolite analysis must have taken the NIOSH course for
						  sampling and evaluating airborne asbestos, tremolite, anthophyllite, and
						  actinolite dust or an equivalent course.
4. When the use of different microscopes contributes to
						  differences between counters and laboratories, the effect of the different
						  microscope shall be evaluated and the microscope shall be replaced, as
						  necessary.
5. Current results of these quality assurance programs
						  shall be posted in each laboratory to keep the microscopists
						  informed.
1. New
						  Appendix A to section
						  5208 filed 2-15-91; operative
						  2-15-91 pursuant to Government Code section
						  11346.2(d)
						  (Register 91, No. 19).
2. Editorial correction of HISTORY 1.
						  (Register 91, No. 45).
3. Amendment of appendix and NOTE filed
						  5-3-96; operative 7-3-96 (Register 96, No. 18).
Note: Authority cited: Section
							 142.3, Labor
							 Code. Reference: Section
							 142.3, Labor
							 Code.