Loading (50 kb)...'
(continued)
At this time, there is no known method to determine the absolute accuracy of the asbestos analysis. Results of samples prepared through the Proficiency Analytical Testing (PAT) Program and analyzed by the OSHA-SLTC showed no significant bias when compared to PAT reference values. The PAT samples were analyzed from 1987 to 1989 (N=36) and the concentration range was from 120 to 1,300 fibers/mm 2.
4. Interferences
Fibrous substances, if present, may interfere with asbestos analysis. Some common fibers are:
fiberglass anhydrite plant fibers perlite veins gypsum some synthetic fibers membrane structures sponge spicules diatoms microorganisms wollastonite
The use of electron microscopy or optical tests such as polarized light, and dispersion staining may be used to differentiate these materials from asbestos when necessary.
5. Sampling
5.1. Equipment
5.1.1. Sample assembly. Conductive filter holder consisting of a 25-mm diameter, 3-piece cassette having a 50-mm long electrically conductive extension cowl. Backup pad: 25-mm, cellulose. Membrane filter: mixed-cellulose ester (MCE), 25-mm, plain, white, 0.4- to 1.2- m m pore size. Notes:
(a) DO NOT RE-USE CASSETTES. (b) Fully conductive cassettes are required to reduce fiber loss to the sides of the cassette due to electrostatic attraction. (c) Purchase filters which have been selected by the manufacturer for asbestos counting or analyze representative filters for fiber background before use. Discard the filter lot if more than 4 fibers/100 fields are found. (d) To decrease the possibility of contamination, the sampling system (filter-backup pad-cassette) for asbestos is usually preassembled by the manufacturer. (e) Other cassettes, such as the Bell-mouth, may be used within the limits of their validation.
5.1.2. Gel bands for sealing cassettes.
5.1.3. Sampling pump. Each pump must be a battery operated, self- contained unit small enough to be placed on the monitored employee and not interfere with the work being performed. The pump must be capable of sampling at the collection rate of 2.5 liters per minute (L/min) for the required sampling time.
5.1.4. Flexible tubing, 6 mm bore.
5.1.5. Pump calibration. Stopwatch and bubble tube/burette or electronic meter.
5.2. Sampling Procedure
5.2.1. Seal the point where the base and cowl of each cassette meet with a gel band or tape.
5.2.2. Charge the pumps completely before beginning.
5.2.3. Connect each pump to a calibration cassette with an appropriate length of 6 mm bore plastic tubing. Do not use luer connectors - the type of cassette specified above has built-in adapters.
5.2.4. Select an appropriate flow rate for the situation being monitored. The sampling flow rate must be between 0.5 and 5.0 L/min for personal sampling and is commonly set between 1 and 2 L/min. Always choose a flow rate that will not produce overloaded filters.
5.2.5. Calibrate each sampling pump before and after sampling with a calibration cassette in-line (Note: This calibration cassette should be from the same lot of cassettes used for sampling). Use a primary standard (e.g. bubble burette) to calibrate each pump. If possible, calibrate at the sampling site.
Note: If sampling site calibration is not possible, environmental influences may affect the flow rate. The extent is dependent on the type of pump used. Consult with the pump manufacturer to determine dependence on environmental influences. If the pump is affected by temperature and pressure changes, correct the flow rate using the formula shown in the section "Sampling Pump Flow Rate Corrections" at the end of this appendix.
5.2.6. Connect each pump to the base of each sampling cassette with flexible tubing. Remove the end cap of each cassette and take each air sample open face. Assure that each sample cassette is held open side down in the employee's breathing zone during sampling. The distance from the nose/mouth of the employee to the cassette should be about 10 cm. Secure the cassette on the collar or lapel of the employee using spring clips or other similar devices.
5.2.7. A suggested minimum air volume when sampling to determine TWA compliance is 25 L. For Excursion Limit (30 min sampling time) evaluations, a minimum air volume of 48 L is recommended.
5.2.8. The most significant problem when sampling for asbestos is overloading the filter with non-asbestos dust. Suggested maximum air sample volumes for specific environments are:
Environment Air Vol. (L)
Asbestos removal operations (visible dust) 100
Asbestos removal operations (little dust) 240
Office environments. 400 to 2,400
CAUTION: Do not overload the filter with dust. High levels of non- fibrous dust particles may obscure fibers on the filter and lower the count or make counting impossible. If more than about 25 to 30% of the field area is obscured with dust, the result may be biased low. Smaller air volumes may be necessary when there is excessive non-asbestos dust in the air.
While sampling, observe the filter with a small flashlight. If there is a visible layer of dust on the filter, stop sampling, remove and seal the cassette, and replace with a new sampling assembly. The total dust loading should not exceed 1 mg.
5.2.9. Blank samples are used to determine if any contamination has occurred during sample handling. Prepare two blanks for the first 1 to 20 samples. For sets containing greater than 20 samples, prepare blanks as 10% of the samples. Handle blank samples in the same manner as air samples with one exception: Do not draw any air through the blank samples. Open the blank cassette in the place where the sample cassettes are mounted on the employee. Hold it open for about 30 seconds. Close and seal the cassette appropriately. Store blanks for shipment with the sample cassettes.
5.2.10. Immediately after sampling, close and seal each cassette with the base and plastic plugs. Do not touch or puncture the filter membrane as this will invalidate the analysis.
5.2.11. Attach and secure a sample seal around each sample cassette in such a way as to assure that the end cap and base plugs cannot be removed without destroying the seal. Tape the ends of the seal together since the seal is not long enough to be wrapped end-to-end. Also wrap tape around the cassette at each joint to keep the seal secure.
5.3. Sample Shipment
5.3.1. Send the samples to the laboratory with paperwork requesting asbestos analysis. List any known fibrous interferences present during sampling on the paperwork. Also, note the workplace operation(s) sampled.
5.3.2. Secure and handle the samples in such that they will not rattle during shipment nor be exposed to static electricity. Do not ship samples in expanded polystyrene peanuts, vermiculite, paper shreds, or excelsior. Tape sample cassettes to sheet bubbles and place in a container that will cushion the samples in such a manner that they will not rattle.
5.3.3. To avoid the possibility of sample contamination, always ship bulk samples in separate mailing containers.
6. Analysis
6.1. Safety Precautions
6.1.1. Acetone is extremely flammable and precautions must be taken not to ignite it. Avoid using large containers or quantities of acetone. Transfer the solvent in a ventilated laboratory hood. Do not use acetone near any open flame. For generation of acetone vapor, use a spark free heat source.
6.1.2. Any asbestos spills should be cleaned up immediately to prevent dispersal of fibers. Prudence should be exercised to avoid contamination of laboratory facilities or exposure of personnel to asbestos. Asbestos spills should be cleaned up with wet methods and/or a High Efficiency Particulate Air (HEPA) filtered vacuum.
CAUTION: Do not use a vacuum without a HEPA filter - It will disperse fine asbestos fibers in the air.
6.2. Equipment
6.2.1. Phase contrast microscope with binocular or trinocular head.
6.2.2. Widefield or Huygenian 10X eyepieces (NOTE: The eyepiece containing the graticule must be a focusing eyepiece. Use a 40X phase objective with a numerical aperture of 0.65 to 0.75).
6.2.3. Kohler illumination (if possible) with green or blue filter.
6.2.4. Walton-Beckett Graticule, type G-22 with 100 plus or minus 2 m m projected diameter.
6.2.5. Mechanical stage. A rotating mechanical stage is convenient for use with polarized light.
6.2.6. Phase telescope.
6.2.7. Stage micrometer with 0.01-mm subdivisions.
6.2.8. Phase-shift test slide, mark II (Available from PTR optics Ltd., and also McCrone).
6.2.9. Precleaned glass slides, 25 mm X 75 mm. One end can be frosted for convenience in writing sample numbers, etc., or paste-on labels can be used.
6.2.10. Cover glass #1 1/2.
6.2.11. Scalpel (#10, curved blade).
6.2.12. Fine tipped forceps.
6.2.13. Aluminum block for clearing filter (see Appendix D and Figure 4).
6.2.14. Automatic adjustable pipette, 100-to 500- m L.
6.2.15. Micropipette, 5 m L.
6.3. Reagents
6.3.1. Acetone (HPLC grade).
6.3.2. Triacetin (glycerol triacetate).
6.3.3. Lacquer or nail polish.
6.4. Standard Preparation
A way to prepare standard asbestos samples of known concentration has not been developed. It is possible to prepare replicate samples of nearly equal concentration. This has been performed through the PAT program. These asbestos samples are distributed by the AIHA to participating laboratories.
Since only about one-fourth of a 25-mm sample membrane is required for an asbestos count, any PAT sample can serve as a "standard" for replicate counting.
6.5. Sample Mounting
Note: See Safety Precautions in Section 6.1. before proceeding. The objective is to produce samples with a smooth (non-grainy) background in a medium with a refractive index of approximately 1.46. The technique below collapses the filter for easier focusing and produces permanent mounts which are useful for quality control and interlaboratory comparison.
An aluminum block or similar device is required for sample preparation.
6.5.1. Heat the aluminum block to about 70 deg.C. The hot block should not be used on any surface that can be damaged by either the heat or from exposure to acetone.
6.5.2. Ensure that the glass slides and cover glasses are free of dust and fibers.
6.5.3. Remove the top plug to prevent a vacuum when the cassette is opened. Clean the outside of the cassette if necessary. Cut the seal and/or tape on the cassette with a razor blade. Very carefully separate the base from the extension cowl, leaving the filter and backup pad in the base.
6.5.4. With a rocking motion cut a triangular wedge from the filter using the scalpel. This wedge should be one-sixth to one-fourth of the filter. Grasp the filter wedge with the forceps on the perimeter of the filter which was clamped between the cassette pieces. DO NOT TOUCH the filter with your finger. Place the filter on the glass slide sample side up. Static electricity will usually keep the filter on the slide until it is cleared.
6.5.5. Place the tip of the micropipette containing about 200 m L acetone into the aluminum block. Insert the glass slide into the receiving slot in the aluminum block. Inject the acetone into the block with slow, steady pressure on the plunger while holding the pipette firmly in place. Wait 3 to 5 seconds for the filter to clear, then remove the pipette and slide from the aluminum block.
6.5.6. Immediately (less than 30 seconds) place 2.5 to 3.5 m L of triacetin on the filter (NOTE: Waiting longer than 30 seconds will result in increased index of refraction and decreased contrast between the fibers and the preparation. This may also lead to separation of the cover slip from the slide).
6.5.7. Lower a cover slip gently onto the filter at a slight angle to reduce the possibility of forming air bubbles. If more than 30 seconds have elapsed between acetone exposure and triacetin application, glue the edges of the cover slip to the slide with lacquer or nail polish.
6.5.8. If clearing is slow, warm the slide for 15 min on a hot plate having a surface temperature of about 50 deg.C to hasten clearing. The top of the hot block can be used if the slide is not heated too long.
6.5.9. Counting may proceed immediately after clearing and mounting are completed.
6.6. Sample Analysis
Completely align the microscope according to the manufacturer's instructions. Then, align the microscope using the following general alignment routine at the beginning of every counting session and more often if necessary.
6.6.1. Alignment
(1) Clean all optical surfaces. Even a small amount of dirt can significantly degrade the image.
(2) Rough focus the objective on a sample.
(3) Close down the field iris so that it is visible in the field of view. Focus the image of the iris with the condenser focus. Center the image of the iris in the field of view.
(4) Install the phase telescope and focus on the phase rings. Critically center the rings. Misalignment of the rings results in astigmatism which will degrade the image.
(5) Place the phase-shift test slide on the microscope stage and focus on the lines. The analyst must see line set 3 and should see at least parts of 4 and 5 but, not see line set 6 or 7. A microscope/microscopist combination which does not pass this test may not be used.
6.6.2. Counting Fibers
(1) Place the prepared sample slide on the mechanical stage of the microscope. Position the center of the wedge under the objective lens and focus upon the sample.
(2) Start counting from one end of the wedge and progress along a radial line to the other end (count in either direction from perimeter to wedge tip). Select fields randomly, without looking into the eyepieces, by slightly advancing the slide in one direction with the mechanical stage control.
(3) Continually scan over a range of focal planes (generally the upper 10 to 15 m m of the filter surface) with the fine focus control during each field count. Spend at least 5 to 15 seconds per field.
(4) Most samples will contain asbestos fibers with fiber diameters less than 1 m m. Look carefully for faint fiber images. The small diameter fibers will be very hard to see. However, they are an important contribution to the total count.
(5) Count only fibers equal to or longer than 5 m m. Measure the length of curved fibers along the curve.
(6) Count fibers which have a length to width ratio of 3:1 or greater.
(7) Count all the fibers in at least 20 fields. Continue counting until either 100 fibers are counted or 100 fields have been viewed; whichever occurs first. Count all the fibers in the final field.
(8) 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 a count of 1/2. 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. If a fiber touches the circle, it is considered to cross the line.
(9) Count bundles of fibers as one fiber unless individual fibers can be clearly identified and each individual fiber is clearly not connected to another counted fiber. See Figure 1 of this appendix for counting conventions.
(10) Record the number of fibers in each field in a consistent way such that filter non-uniformity can be assessed.
(11) Regularly check phase ring alignment.
(12) When an agglomerate (mass of material) covers more than 25% of the field of view, reject the field and select another. Do not include it in the number of fields counted.
(13) Perform a "blind recount" of 1 in every 10 filter wedges (slides). Re-label the slides using a person other than the original counter.
6.7. Fiber Identification
As previously mentioned in Section 1.3., PCM does not provide positive confirmation of asbestos fibers. Alternate differential counting techniques should be used if discrimination is desirable. Differential counting may include primary discrimination based on morphology, polarized light analysis of fibers, or modification of PCM data by Scanning Electron or Transmission Electron Microscopy.
A great deal of experience is required to routinely and correctly perform differential counting. It is discouraged unless it is legally necessary. Then, only if a fiber is obviously not asbestos should it be excluded from the count. Further discussion of this technique can be found in reference 8.10. If there is a question whether a fiber is asbestos or not, follow the rule: "WHEN IN DOUBT, COUNT."
6.8. Analytical Recommendations - Quality Control System
6.8.1. All individuals performing asbestos analysis must have taken the NIOSH course for sampling and evaluating airborne asbestos or an equivalent course.
6.8.2. Each laboratory engaged in asbestos counting shall set up a slide trading arrangement with at least two other laboratories in order to compare performance and eliminate inbreeding of error. The slide exchange occurs at least semiannually. The round robin results shall be posted where all analysts can view individual analyst's results.
6.8.3. Each laboratory engaged in asbestos counting shall participate in the Proficiency Analytical Testing Program, the Asbestos Analyst Registry or equivalent.
6.8.4. Each analyst shall select and count prepared slides from a "slide bank". These are quality assurance counts. The slide bank shall be prepared using uniformly distributed samples taken from the workload. Fiber densities should cover the entire range routinely analyzed by the laboratory. These slides are counted blind by all counters to establish an original standard deviation. This historical distribution is compared with the quality assurance counts. A counter must have 95% of all quality control samples counted within three standard deviations of the historical mean. This count is then integrated into a new historical mean and standard deviation for the slide.
The analyses done by the counters to establish the slide bank may be used for an interim quality control program if the data are treated in a proper statistical fashion.
7. Calculations
7.1. Calculate the estimated airborne asbestos fiber concentration on the filter sample using the following formula:
where:
AC = Airborne fiber concentration FB = Total number of fibers greater than 5 m m counted FL = Total number of fields counted on the filter BFB = Total number of fibers greater than 5 m m counted in the blank BFL = Total number of fields counted on the blank ECA = Effective collecting area of filter (385 mm 2 nominal for a 25 - mm filter.) FR = Pump flow rate (L/min) MFA = Microscope count field area (mm 2). This is 0.00785 mm 2 for a Walton-Beckett Graticule. T = Sample collection time (min) 1,000 = Conversion of L to cc
Note: The collection area of a filter is seldom equal to 385 mm 2 . It is appropriate for laboratories to routinely monitor the exact diameter using an inside micrometer. The collection area is calculated according to the formula:
Area = P (d/2) 2
7.2. Short-Cut Calculation
Since a given analyst always has the same interpupillary distance, the number of fields per filter for a particular analyst will remain constant for a given size filter. The field size for that analyst is constant (i.e. the analyst is using an assigned microscope and is not changing the reticle).
For example, if the exposed area of the filter is always 385 mm 2 and the size of the field is always 0.00785 mm 2 the number of fields per filter will always be 49,000. In addition it is necessary to convert liters of air to cc. These three constants can then be combined such that ECA/(1,000 x MFA)=49. The previous equation simplifies to:
7.3. Recount Calculations
As mentioned in step 13 of Section 6.6.2., a "blind recount" of 10% of the slides is performed. In all cases, differences will be observed between the first and second counts of the same filter wedge. Most of these differences will be due to chance alone, that is, due to the random variability (precision) of the count method. Statistical recount criteria enables one to decide whether observed differences can be explained due to chance alone or are probably due to systematic differences between analysts, microscopes, or other biasing factors.
The following recount criterion is for a pair of counts that estimate AC in fibers/cc. The criterion is given at the type-I error level. That is, there is 5% maximum risk that we will reject a pair of counts for the reason that one might be biased, when the large observed difference is really due to chance.
Reject a pair of counts if:
Where:
AC(1) = lower estimated airborne fiber concentration
AC(2) = higher estimated airborne fiber concentration
AC(avg) = average of the two concentration estimates
CV(FB) = CV for the average of the two concentration estimates
If a pair of counts are rejected by this criterion then, recount the rest of the filters in the submitted set. Apply the test and reject any other pairs failing the test. Rejection shall include a memo to the industrial hygienist stating that the sample failed a statistical test for homogeneity and the true air concentration may be significantly different than the reported value.
7.4. Reporting Results
Report results to the industrial hygienist as fibers/cc. Use two significant figures. If multiple analyses are performed on a sample, an average of the results is to be reported unless any of the results can be rejected for cause.
8. References
8.1. Dreesen, W.C., et al., U.S. Public Health Service: A Study of Asbestosis in the Asbestos Textile Industry (Public Health Bulletin No. 241), U.S. Treasury Dept., Washington, DC, 1938.
8.2. Asbestos Research Council: The Measurement of Airborne Asbestos Dust by the Membrane Filter Method (Technical Note), Asbestos Research Council, Rockdale, Lancashire, Great Britain, 1969.
8.3. Bayer, S.G., Zumwalde, R.D., Brown, T.A., Equipment and Procedure for Mounting Millipore Filters and Counting Asbestos Fibers by Phase Contrast Microscopy, Bureau of Occupational Health, U.S. Dept. of Health, Education and Welfare, Cincinnati, OH, 1969.
8.4. NIOSH Manual of Analytical Methods, 2nd ed., Vol. 1 (DHEW/ NIOSH Pub. No. 77-157-A). National Institute for Occupational Safety and Health, Cincinnati, OH, 1977. pp. 239-1 - 239-21.
8.5. Asbestos, Code of Federal Regulations 29 CFR 1910.1001. 1971.
8.6. Occupational Exposure to Asbestos, Tremolite, Anthophyllite, and Actinolite. Final Rule, Federal Register 51:119 (20 June 1986). pp. 22612- 22790.
8.7. Asbestos, Tremolite, Anthophyllite, and Actinolite, Code of Federal Regulations 1910.1001. 1988. pp. 711-752.
8.8. Criteria for a Recommended Standard - Occupational Exposure to Asbestos (DHEW/NIOSH Pub. No. HSM 72-10267), National Institute for Occupational Safety and Health, NIOSH, Cincinnati, OH, 1972. pp. III-1 - III-24.
8.9. Leidel, N.A., Bayer, S.G., Zumwalde, R.D., Busch, K.A., USPHS/NIOSH Membrane Filter Method for Evaluating Airborne Asbestos Fibers (DHEW/NIOSH Pub. No. 79-127). National Institute for Occupational Safety and Health, Cincinnati, OH, 1979.
8.10. Dixon, W.C., Applications of Optical Microscopy in Analysis of Asbestos and Quartz, Analytical Techniques in Occupational Health Chemistry, edited by D.D. Dollberg and A.W. Verstuyft. Wash. D.C.: American Chemical Society, (ACS Symposium Series 120) 1980. pp. 13-41.
Quality Control
The OSHA asbestos regulations require each laboratory to establish a quality control program. The following is presented as an example of how the OSHA-SLTC constructed its internal CV curve as part of meeting this requirement. Data is from 395 samples collected during OSHA compliance inspections and analyzed from October 1980 through April 1986.
Each sample was counted by 2 to 5 different counters independently of one another. The standard deviation and the CV statistic was calculated for each sample. This data was then plotted on a graph of CV vs. fibers/mm 2. A least squares regression was performed using the following equation:
CV = antilog 10 [A(log 10 (x)) 2 +B(log 10 (x))+C]
where:
x = the number of fibers/mm 2
Application of least squares gave:
A = 0.182205 B = 0.973343 C = 0.327499
Using these values, the equation becomes:
CV = antilog 10 [0.182205(log 10 (x)) 2 + 0.973343(log 10 (x)) + 0.327499]
Sampling Pump Flow Rate Corrections
This correction is used if a difference greater than 5% in ambient temperature and/or pressure is noted between calibration and sampling sites and the pump does not compensate for the differences.
Where:
Q(act) = actual flow rate
Q(cal) = calibrated flow rate (if a rotameter was used, the rotameter value)
P(cal) = uncorrected air pressure at calibration
P(act) = uncorrected air pressure at sampling site
T(act) = temperature at sampling site (K)
T(cal) = temperature at calibration (K)
Walton-Beckett Graticule
When ordering the Graticule for asbestos counting, specify the exact disc diameter needed to fit the ocular of the microscope and the diameter (mm) of the circular counting area. Instructions for measuring the dimensions necessary are listed:
(1) Insert any available graticule into the focusing eyepiece and focus so that the graticule lines are sharp and clear.
(2) Align the microscope.
(3) Place a stage micrometer on the microscope object stage and focus the microscope on the graduated lines.
(4) Measure the magnified grid length, PL ( m m), using the stage micrometer.
(5) Remove the graticule from the microscope and measure its actual grid length, AL (mm). This can be accomplished by using a mechanical stage fitted with verniers, or a jeweler's loupe with a direct reading scale.
(6) Let D = 100 m m. Calculate the circle diameter, d c (mm), for the Walton-Beckett graticule and specify the diameter when making a purchase:
AL X D
d c = ________
PL
Example: If PL = 108 m m, AL = 2.93 mm and D = 100 m m, then,
2.93 x 100
d c = ___________ =2.71mm
108
(7) Each eyepiece-objective-reticle combination on the microscope must be calibrated. Should any of the three be changed (by zoom adjustment, disassembly, replacement, etc.), the combination must be recalibrated. Calibration may change if interpupillary distance is changed.
Measure the field diameter, D (acceptable range: 100 plus or minus 2 m m) with a stage micrometer upon receipt of the graticule from the manufacturer. Determine the field area (mm(2)).
Field Area = PI(D/2) 2
If D = 100 mu = 0.1 mm then
Field Area = PI (0.1 mm/2) 2 = 0.00785mm 2
The Graticule is available from: Graticules Ltd., Morley Road, Tonbridge TN9 IRN, Kent, England (Telephone 011-44-732-359061). Also available from PTR Optics Ltd., 145 Newton Street, Waltham, MA 02154 [telephone (617) 891-6000] or McCrone Accessories and Components, 2506 S. Michigan Ave., Chicago, IL 60616 [phone (312)- 842-7100]. The graticule is custom made for each microscope.
Figure 1: Walton-Beckett Graticule with some explanatory fibers.
Counts for the Fibers in the Figure
Structure No. Count Explanation
1 to 6 1 Single fibers all contained within the Circle.
7 1/2 Fiber crosses circle once.
8 0 Fiber too short.
9 2 Two crossing fibers.
10 0 Fiber outside graticule.
11 0 Fiber crosses graticule twice.
12 1/2 Although split, fiber only crosses once.
Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.
Appendix C
Qualitative and Quantitative Fit Testing Procedures
Mandatory
[See Section 5144, Appendix A]
Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.
Appendix D
Medical Questionnaires
Manditory
This mandatory appendix contains the medical questionnaires that must be administered to all employees who are exposed to asbestos above the permissible exposure limit, and who will therefore be included in their employer's medical surveillance program. Part 1 of the appendix contains the Initial Medical Questionnaire, which must be obtained for all new hires who will be covered by the medical surveillance requirements. Part 2 includes the abbreviated Periodical Medical Questionnaire, which must be administered to all employees who are provided periodic examinations under the medical surveillance provisions of the standard.
Part 1 INITIAL MEDICAL QUESTIONNAIRE
1. NAME______________________________________________________
2. SOCIAL
SECURITY# _____ _____ _____ _____ _____ _____ _____ _____ _____
1 2 3 4 5 6 7 8 9
3. CLOCK
NUMBER _____ _____ _____ _____ _____ _____
10 11 12 12 14 15
4. PRESENT OCCUPATION________________________________________
5. PLANT_____________________________________________________
6. ADDRESS___________________________________________________
7. __________________________________________________________
(Zip Code)
8. TELEPHONE NUMBER__________________________________________
9. INTERVIEWER_______________________________________________
10. DATE
____________ _____ _____ _____ _____ _____ _____
16 17 18 19 20 21
11. Date of Birth _____ _____ _____
Month Day Year
_____ _____ _____ _____ _____ _____
22 23 24 25 26 27
12. Place of Birth ___________________________________________
13. Sex 1. Male _____
2. Female _____
14. What is your marital status? 1. Single _____
2. Married _____
3. Widowed _____
4. Separated/Divorced _____
15. Race 1. White _____
2. Black _____
3. Asian _____
4. Hispanic _____
5. Indian _____
6. Other _____
16. What is the highest grade completed in school?
___________________________________________________
(For example 12 years is completion of high school)
OCCUPATIONAL
Appendix E
Interpretation and Classification of Chest Roentgenograms Mandatory
(a) Chest roentgenograms shall be interpreted and classified in accordance with a professionally accepted classification system and recorded on an interpretation form following the format of the CDC/NIOSH (M) 2.8 form. As a minimum, the content within the bold lines of this form (items 1 through 4) shall be included. This form is not to be submitted to NIOSH.
(b) Roentgenograms shall be interpreted and classified only by a B-reader, a board eligible/certified radiologist, or an experienced physician with known expertise in pneumoconioses.
(c) All interpreters, whenever interpreting chest roentgenograms made under this section, shall have immediately available for reference a complete set of the ILO-U/C International Classification of Radiographs for Pneumoconioses, 1980.
Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.
Appendix F
Work Practices and Engineering Controls for Automotive Brake and Clutch
Inspection, Disassembly, Repair, and Assembly
Mandatory
This mandatory appendix specifies engineering controls and work practices that must be implemented by the employer during automotive brake and clutch inspection, disassembly, repair, and assembly operations. Proper use of these engineering controls and work practices by trained employees will reduce employees' asbestos exposure below the permissible exposure level during clutch and brake inspection, disassembly, repair, and assembly operations. The employer shall institute engineering controls and work practices using either the method set forth in paragraph [A] or paragraph [B] of this appendix, or any other method which the employer can demonstrate to be equivalent in terms of reducing employee exposure to asbestos, as defined, and which meets the requirements described in paragraph [C] of this appendix. For those facilities in which no more than 5 pairs of brakes or 5 clutches are inspected, disassembled, reassembled, and/or repaired per week, the method set forth in paragraph [D] of this appendix may be used.
[A] Negative Pressure Enclosure/HEPA Vacuum System Method:
(1) The brake and clutch inspection, disassembly, repair, and assembly operations shall be enclosed to cover and contain the clutch or brake assembly and to prevent the release of asbestos fibers into the worker's breathing zone.
(2) the enclosure shall be sealed tightly and thoroughly inspected for leaks before work begins on brake and clutch inspection, disassembly, repair, and assembly.
(3) The enclosure shall be such that the worker can clearly see the operation and shall provide impermeable sleeves through which the worker can handle the brake and clutch inspection, disassembly, repair and assembly. The integrity of the sleeves and ports shall be examined before work begins.
(4) A HEPA-filtered vacuum shall be employed to maintain the enclosure under negative pressure throughout the operation. Compressed-air may be used to remove asbestos fibers or particles from the enclosure.
(5) The HEPA vacuum shall be used first to loosen the asbestos-containing residue from the brake and clutch parts, and then to evacuate the loosened asbestos-containing material from the enclosure and capture the material in the vacuum filter.
(6) The vacuum's filter, when full, shall be first wetted with a fine mist of water, then removed and placed immediately in an impermeable container, labeled according to subsection (j) (4) of this section, and disposed of according to subsection (k) of this section.
(7) Any spills or releases of asbestos-containing waste material from inside of the enclosure or vacuum hose or vacuum filter shall be immediately cleaned up and disposed of according to subsection (k) of this section.
[B] Low Pressure/Wet Cleaning Method:
(1) A catch basin shall be placed under the brake assembly, positioned to avoid splashes and spills.
(2) The reservoir shall contain water containing an organic solvent or wetting agent. The flow of liquid shall be controlled such that the brake assembly is gently flooded to prevent the asbestos-containing brake dust from becoming airborne.
(3) The aqueous solution shall be allowed to flow between the brake drum and brake support before the drum is removed.
(4) After removing the brake drum, the wheel hub and back of the brake assembly shall be thoroughly wetted to suppress dust.
(5) The brake support plate, brake shoes and brake components used to attach the brake shoes shall be thoroughly washed before removing the old shoes.
(6) In systems using filters, the filters when full shall be first wetted with a fine mist of water, then removed and placed immediately in an impermeable container labeled according to subsection (j) (4) of this section, and disposed of according to subsection (k) of this section.
(7) Any spills of asbsetos-containing aqueous solution or any asbsetos-containing waste material shall be cleaned up immediately and disposed of according to subsection (k) of this section.
(8) The use of dry brushing during low pressure/wet cleaning operations is prohibited.
[C] Equivalent Methods:
An equivalent method is one which has sufficient written detail so that it can be reproduced, and for which it has been demonstrated that the exposures resulting from the equivalent method are equal to or less than the exposures which would result from the use of the method described in paragraph [A] of this appendix. For purposes of making this comparison, the employer shall assume that exposures resulting from the use of the method described in paragraph [A] of this appendix shall not exceed 0.016 f/cc, as measured by the OSHA reference method and as averaged over at least 18 personal samples.
[D] Wet Method:
(1) A spray bottle, hose nozzle, or other implement capable of delivering a fine mist of water or amended water, or other deliverysystem capable of delivering water at low pressure, shall be used to first thoroughly wet the brake and clutch parts. Brake and clutch components shall then be wiped clean with a cloth.
(2) The cloth shall be placed in an impermeable container, labeled according to subsection (j) (4) of this section, and then disposed of according to subsection (k) of this section; or the cloth shall be laundered in a way to prevent the release of asbestos fibers in excess of 0.1 fiber per cubic centimeter of air.
(3) Any spills of solvent or any asbstos-containing waste material shall be cleaned up immediately according to subsection (k) of this section.
(4) The use of dry brushing during the wet method operations is prohibited.
Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.
Appendix G
Substance Technical Information for Asbestos Non-Mandatory
I. Substance Identification
A. Substance: "Asbestos" is the name of a class of magnesium-silicate minerals that occur in fibrous form. Minerals that are included in this group are chrysotile, crocidolite, amosite, anthophyllite asbestos, tremolite asbestos, and actinolite asbestos.
B. Asbestos is used in the manufacture of heat-resistant clothing, automotive brake and clutch linings, and a variety of building materials including floor tiles, roofing felts, ceiling tiles, asbestos-cement pipe and sheet, and fire-resistant drywall. Asbestos is also present in pipe and boiler insulation materials, and in sprayed-on materials located on beams, in crawlspaces, and between walls.
C. The potential for an asbestos-containing product to release breathable fibers depends on its degree of friability. "Friable" means that the material can be crumbled with hand pressure and is therefore likely to emit fibers. The fibrous fluffy sprayed-on materials used for fireproofing, insulation, or sound proofing are considered to be friable, and they readily release airborne fibers if disturbed. Materials such as vinyl-asbestos floor tile or roofing felt are considered non-friable if intact and generally do not emit airborne fibers unless subjected to sanding, sawing and other aggressive operations. Asbestos-cement pipe or sheet can emit airborne fibers if the materials are cut or sawed, or if they are broken.
D. Permissible exposure: Exposure to airborne asbestos fibers may not exceed 0.1 fibers per cubic centimeter of air (0.1 f/cc) averaged over the 8-hour workday, and 1 fiber per cubic centimeter of air (1.0 f/cc) averaged over a 30 minute work period.
II. Health Hazard Data
A. Asbestos can cause disabling respiratory disease and various types of cancers if the fibers are inhaled. Inhaling or ingesting fibers from contaminated clothing or skin can also result in these diseases. The symptoms of these diseases generally do not appear for 20 or more years after initial exposure.
B. Exposure to asbestos has been shown to cause lung cancer, mesothelioma, and cancer of the stomach and colon. Mesothelioma is a rare cancer of the thin membrane lining of the chest and abdomen. Symptoms of mesothelioma include shortness of breath, pain in the walls of the chest, and/or abdominal pain.
III. Respirators and Protective Clothing
A. Respirators: You are required to wear a respirator when performing tasks that result in asbestos exposure that exceeds the permissible exposure limit (PEL) of 0.1 f/cc and when performing certain designated operations. Air-purifying respirators equipped with a high-efficiency particulate air (HEPA) filter can be used where airborne asbestos fiber concentrations do not exceed 1.0 f/cc; otherwise, more protective respirators such as air-supplied, positive-pressure, full facepiece respirators must be used. Disposable respirators or dust masks are not permitted to be used for asbestos work. For effective protection, respirators must fit your face and head snugly. Your employer is required to conduct fit tests when you are first assigned a respirator and annually thereafter. Respirators should not be loosened or removed in work situations where their use is required.
B. Protective Clothing: You are required to wear protective clothing in work areas where asbestos concentrations exceed the permissible exposure limit (PEL) of 0.1 f/cc.
IV. Disposal Procedures and Clean-up
A. Wastes that are generated by processes where asbestos is present include:
1. Empty asbestos shipping containers.
2. Process wastes such as cuttings, trimmings, or reject material.
3. Housekeeping waste from wet-sweeping or HEPA-vacuuming.
4. Asbestos fireproofing or insulating material that is removed from buildings.
5. Asbestos-containing building products removed during building renovation or demolition.
6. Contaminated disposable protective clothing.
B. Empty shipping bags can be flattened under exhaust hoods and packed into airtight containers for disposal. Empty shipping drums are difficult to clean and should be sealed.
C. Vacuum bags or disposable paper filters should not be cleaned, but should be sprayed with a fine water mist and placed into a labeled waste container.
D. Process waste and housekeeping waste should be wetted with water, or a mixture of water, and surfactant prior to packaging in disposable containers.
E. Asbestos-containing material that is removed from buildings must be disposed of in leak-tight 6-mil plastic bags, plastic-lined cardboard containers, or plastic-lined metal containers. These wastes, which are removed while wet, should be sealed in containers before they dry out to minimize the release of asbestos fibers during handling.
V. Access to Information
A. Each year, your employer is required to inform you of the information contained in this standard, and appendices, for asbestos. In addition, your employer must instruct you in the proper work practices for handling asbestos-containing materials, and the correct use of protective equipment.
B. Your employer is required to determine whether you are being exposed to asbestos. Your employer must treat exposure to thermal system insulation and sprayed-on and troweled-on surfacing material as asbestos exposure, unless results of laboratory analysis show that the material does not contain asbestos. You or your representative has the right to observe employee measurements and to record the results obtained. Your employer is required to inform you of your exposure, and, if you are exposed above the permissible exposure limit, he or she is required to inform you of the actions that are being taken to reduce your exposure to within the permissible limit.
C. Your employer is required to keep records of your exposures and medical examinations. These exposure records must be kept for at least thirty (30) years, Medical records must be kept for the period of your employment plus thirty (30) years.
D. Your employer is required to release your exposure and medical records to your physician or designated representative upon your written request.
Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.
Appendix H
Medical Surveillance Guidelines for Asbestos Non-Mandatory
I. Route of Entry: Inhalation, Ingestion
II. Toxicology
Clinical evidence of the adverse effects associated with exposure to asbestos is present in the form of several well-conducted epidemiological studies of occupationally exposed workers, family contacts of workers, and persons living near asbestos mines. These studies have shown a definite association between exposure to asbestos and an increased incidence of lung cancer, pleural and peritoneal mesothelioma, gastrointestinal cancer, and asbestosis. The latter is a disabling fibrotic lung disease that is caused only by exposure to asbestos. Exposure to asbestos has also been associated with an increased incidence of esophageal, kidney, laryngeal, pharyngeal, and buccal cavity cancers. As with other known chronic occupational diseases, disease associated with asbestos generally appears about 20 years following the first occurrence of exposure. There are no known acute effects associated with exposure to asbestos.
Epidemiological studies indicate that the risk of lung cancer among exposed workers who smoke cigarettes is greatly increased over the risk of lung cancer among non-exposed smokers or exposed nonsmokers. These studies suggest that cessation of smoking will reduce the risk of lung cancer for a person exposed to asbestos but will not reduce it to the same level of risk as that existing for an exposed worker who has never smoked.
III. Signs and Symptoms of Exposure-Related Disease
The signs and symptoms of lung cancer or gastrointestinal cancer induced by exposure to asbestos are not unique, except that a chest X-ray of an exposed patient with lung cancer may show pleural plaques, pleural calcification, or pleural fibrosis. Symptoms characteristic of mesothelioma include shortness of breath, pain in the walls of the chest, or abdominal pain. Mesothelioma has a much longer latency period compared with lung cancer (40 years versus 15-20 years), and mesothelioma is therefore likely to be found among workers who were first exposed to asbestos at an early age. Mesothelioma is always fatal.
Asbestosis is pulmonary fibrosis caused by the accumulation of asbestos fibers in the lungs. Symptoms include shortness of breath, coughing, fatigue, and vague feelings of sickness. When the fibrosis worsens, shortness of breath occurs even at rest. The diagnosis of asbestosis is based on a history of exposure to asbestos, the presence of characteristic radiologic changes, end inspiratory crackles (rales), and other clinical features of fibrosing lung disease. Pleural plaques and thickening are observed on X-rays taken during the early stages of the disease. Asbestosis is often a progressive disease even in the absence of continued exposure, although this appears to be a highly individualized characteristic. In severe cases, death may be caused by respiratory or cardiac failure.
IV. Surveillance and Preventive Considerations
As noted above, exposure to asbestos has been linked to an increased risk of lung cancer, mesothelioma, gastrointestinal cancer, and asbestosis among occupationally exposed workers. Adequate screening tests to determine an employee's potential for developing serious chronic diseases, such as cancer, from exposure to asbestos do not presently exist. However, some tests, particularly chest X-rays and pulmonary function tests, may indicate that an employee has been overexposed to asbestos, thus increasing his or her risk of developing exposure-related chronic disease. It is important for the physician to become familiar with the operating conditions in which occupational exposure to asbestos is likely to occur. This is particularly important in evaluating medical and work histories and in conducting physical examinations. When an active employee has been identified as having been overexposed to asbestos, measures taken by the employer to eliminate or mitigate further exposure should also lower the risk of serious long-term consequences.
The employer is required to institute a medical surveillance program for all employees who are or will be exposed to asbestos at or above the permissible exposure limit (0.1 fiber per cubic centimeter of air). All examinations and procedures must be performed by or under the supervision of a licensed physician, at a reasonable time and place, and at no cost to the employee.
Although broad latitude is given to the physician in prescribing specific tests to be included in the medical surveillance program, OSHA requires inclusion of the following elements in the routine examination:
(i) Medical and work histories with special emphasis directed to symptoms of the respiratory system, cardiovascular system, and digestive tract.
(ii) Completion of one of the respiratory disease questionnaires contained in Appendix D: Part 1 for the initial examination and part 2 for periodic examinations.
(iii) A physical examination including a chest X-ray (at the discretion of the examining physician for construction work) and pulmonary function testing that includes measurement of the employee's forced vital capacity (FVC) and forced expiratory volume at one second (FEV 1).
(iv) Any laboratory or other test that the examining physician deems by sound medical practice to be necessary or appropriate.
The employer is required to make the prescribed tests available at least annually to those employees covered; more often than specified if recommended by the examining physician; and upon termination of employment.
The employer is required to provide the physician with the followinginformation: a copy of this standard and appendices; a description of the employee's work assignments as they relate to asbestos exposure; the employee's representative level of exposure to asbestos; a description of any personal protective and respiratory equipment used; and information from previous medical examinations of the affected employee that is not otherwise available to the physician. Making this information available to the physician will aid in the evaluation of the employee's health in relation to assigned duties and fitness to wear personal protective equipment, if required. (continued)