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 109 - Hazardous Substances and Processes › Appendix A - Air Sampling and Analytical Procedures for Determining Concentrations of Cotton Dust

Current through Register 2024 Notice Reg. No. 28, July 12, 2024
I. SAMPLING LOCATIONS
The sampling procedures must be designed so that
						  samples of the actual dust concentrations are collected accurately and
						  consistently and reflect the concentrations of dust at the place and time of
						  sampling. Sufficient number of 6-hour area samples in each distinct work area
						  of the plant should be collected at locations which provide representative
						  samples of air to which the worker is exposed. In order to avoid filter
						  overloading, sampling time may be shortened when sampling in dusty areas.
						  Samples in each work area should be gathered simultaneously or sequentially
						  during a normal operating period. The daily time-weighted average (TWA)
						  exposure of each worker can then be determined by using the following
						  formula:
(T1C1
								  + T2C2 .... + Tn Cn),
TWA
								  =
_______________________________________________
Total Hours Exposed
where:
T1,T2..........................
Tn=the number of hours spent in a given location; and
C1,C2..........................
Cn=the dust concentration in the same location.
A time-weighted average concentration should be
						  computed for each worker and properly logged and maintained on file for
						  review.
II. SAMPLING EQUIPMENT
A. Sampler:
The instrument selected for monitoring is the
						  Lumsden-Lynch vertical elutriator. It should operate at a flow rate of 7.4 plus
						  or minus 0.2 liters/minute.
The samplers should be cleaned prior to sampling. The
						  pumps should be monitored during sampling.
B. Filter Holder:
A three-piece cassette constructed of polystyrene
						  designed to hold a 37 mm diameter filter should be used. Care must be exercised
						  to assure that an adequate seal exists between elements of the cassette.
C. Filters and Support Pads:
The membrane filters used should be polyvinyl chloride
						  with a 5-[MICRO]m pore size and 37 mm diameter. A support pad, commonly called
						  a backup pad, should be used under the filter membrane in the field monitor
						  cassette.
D. Balance:
A balance sensitive to 10 micrograms should be
						  used.
III. INSTRUMENT CALIBRATION PROCEDURE
Samplers shall be calibrated when first received from
						  the factory, after repair, and after receiving any abuse. The samplers should
						  be calibrated in the laboratory both before they are used in the field and
						  after they have been used to collect a large number of field samples. The
						  primary standard, such as a wet test meter, should be used. Instructions of
						  calibration with the wet test meter follow. If another calibration device is
						  selected, equivalent procedures should be used:
(a) Level wet test meter. Check the water level which
						  should just touch the calibration point at the left side of the meter. If water
						  level is low, add water 1-2° F warmer than room temperature to the fill
						  point. Run the meter for 30 minutes before calibration;
(b) Place the polyvinyl chloride membrane filter in the
						  filter cassette;
(c) Assemble the calibration sampling train;
(d) Connect the wet test meter to the train. The
						  pointer on the meter should run clockwise and a pressure drop of not more than
						  1.0 inch of water indicated. If the pressure drop is greater than 1.0 inch,
						  disconnect and check the system;
(e) Operate the system for ten minutes before starting
						  the calibration;
(f) Check the vacuum gauge on the pump to assure that
						  the pressure drop across the orifice exceeds 17 inches of mercury;
(g) Record the following on calibration data
						  sheets;
(1) Wet test meter reading, start and finish;
(2) Elapsed time, start and finish (at least two
						  minutes);
(3) Pressure drop at manometer;
(4) Air temperature;
(5) Barometric pressure; and
(6) Limiting orifice number;
(h) Calculate the flow rate and compare against the
						  flow of 7.4 plus or minus 0.2 liters/minute. If flow is between these limits
						  perform calibration again, average results, and record orifice number and flow
						  rate. If flow is not within these limits, discard or modify orifice and repeat
						  procedure.
(i) Record the name of the person performing the
						  calibration, the date, serial number of the wet test meter, and the number of
						  the critical orifices being calibrated.
IV. SAMPLING PROCEDURE
A. Sampling data sheets should include a log of:
1. The date of the sample collection;
2. The time of sampling;
3. The location of the sampler;
4. The sampler serial number;
5. The cassette number;
6. The time of starting and stopping the sampling and
						  the duration of sampling;
7. The weight of the filter before and after
						  sampling;
8. The weight of the dust collected (corrected for
						  controls);
9. The dust concentration measured;
10. Other pertinent information; and
11. Name of person taking sample;
B. Assembly of filter cassette should be as
						  follows:
1. Loosely assemble 3-piece cassette;
2. Number cassette;
3. Place absorbent pad in cassette;
4. Weigh filter to an accuracy of 10 [MICRO]g;
5. Place filter in cassette;
6. Record weight of filter in log, using cassette
						  number for identification;
7. Fully assemble cassette, using pressure to force
						  parts tightly together;
8. Install plugs top and bottom;
9. Put shrink band on cassette, covering joint between
						  center and bottom parts of cassette; and
10. Set cassette aside until shrink band dries
						  thoroughly.
C. Sampling collection should be performed as
						  follows:
1. Clean lint out of the motor and elutriator;
2. Install vertical elutriator in sampling locations
						  with inlet 4 ½ to 5 ½ feet from floor (breathing zone
						  height);
3. Remove top section of cassette;
4. Install cassette in ferrule of elutriator;
5. Tape cassette to ferrule with masking tape or
						  similar material for air-tight seal;
6. Remove bottom plug of cassette and attach hose
						  containing critical orifice;
7. Start elutriator pump and check to see if gauge
						  reads above 17 inches of Hg vacuum;
8. Record starting time, cassette number, and sampler
						  number;
9. At end of sampling period, stop pump and record
						  time;
10. Controls with each batch of samples collected; two
						  additional filter cassettes should be subjected to exactly the same handling as
						  the samples, except that they are not opened. These control filters should be
						  weighted in the same manner as the sample filters.
Any difference in weight in the control filters would
						  indicate that the procedure for handling sample filters may not be adequate and
						  should be evaluated to ascertain the cause of the difference, whether and what
						  necessary corrections must be made, and whether additional samples must be
						  collected.
D. Shipping:
The cassette with samples should be collected along
						  with the appropriate number of blanks, and shipped to the analytical laboratory
						  in a suitable container to prevent damage in transit.
E. Weighing of the sample should be achieved as
						  follows:
1. Remove shrink band;
2. Remove top and middle sections of the cassette and
						  bottom plug;
3. Remove filter from cassette and weigh to an accuracy
						  of 10 [MICRO]g; and
4. Record weight in log against original weight.
F. Calculation of volume of air sampled should be
						  determined as follows:
1. From starting and stopping times of sampling period,
						  determine length of time in minutes of sampling period;
2. Multiply sampling time in minutes by flow rate of
						  critical orifices in liters per minute divide by 1000 to find air quality in
						  cubic meters.
G. Calculation of dust concentrations should be made as
						  follows:
1. Subtract weight of clean filter from dirty filter
						  and apply control correction to find actual weight of sample. Record this
						  weight (in [MICRO]g) in log; and
2. Divide mass of sample in ug by air volume in cubic
						  meters to find dust concentration in [MICRO]g/m3.
						  Record in log.