California Code of Regulations › Title 8 - Industrial Relations › Division 1 - Department of Industrial Relations › Chapter 4 - Division of Industrial Safety › Subchapter 18 - Ship Building, Ship Repairing and Ship Breaking Safety Orders › Article 4 - Control of Hazardous Work › 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 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
						Method 7400) 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 (f) 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 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. Other cassettes such as the Bell-mouth may be used
						within the limits of their validation. 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% 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. In the absence of other information, count all
						particles as asbestos that have a length-to-width ratio (aspect ratio) of 3 to
						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. Intralaboratory 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, anthopyllite, 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,
						anthopyllite, and actinolite analysis must have taken the NIOSH course for
						sampling and evaluating airborne asbestos, tremolite, anthopyllite, 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.
Note: Authority cited: Section
						  142.3, Labor
						  Code. Reference: Section
						  142.3, Labor
						  Code.