Washington Administrative Code › Title 296 - Labor and Industries, Department of › Chapter 296-62 - General occupational health standards › Part N - COTTON DUST › Section 296-62-14541 - Appendix D-Pulmonary function standards for cotton dust standard

Current through Register Vol. 24-14, July 15, 2024
The spirometric measurements of pulmonary function must
				  conform to the following minimum standards, and these standards are not
				  intended to preclude additional testing or alternate methods which can be
				  determined to be superior.
(1)
Apparatus.
(a)  The instrument
				must be accurate to within ± 50 milliliters or within ± 3 percent
				of reading, whichever is greater.
(b)
				 The instrument should be capable of measuring vital capacity from
				0 to 7 liters BTPS.
(c)  The
				instrument must have a low inertia and offer low resistance to airflow such
				that the resistance to airflow at 12 liters per second must be less than 1.5
				cm. H2O/liter/sec.
(d)
				 The zero time point for the purpose of timing the
				FEV1 must be determined by extrapolating the steepest
				portion of the volume time curve back to the maximal inspiration volume (1, 2,
				3, 4) or by an equivalent method.
(e)
				 Instruments incorporating measurements of airflow to determine
				volume must conform to the same volume accuracy stated in (a) of this
				subsection when presented with flow rates from at least 0 to 12 liters per
				second.
(f)  The instrument or user
				of the instrument must have means of correcting volumes to a body temperature
				saturated with water vapor (BTPS) under conditions of varying ambient
				spirometer temperatures and barometric pressures.
(g)  The instrument used must provide a
				tracing or display of either flow versus volume or volume versus time during
				the entire forced expiration. A tracing or display is necessary to determine
				whether the patient has performed the test properly. The tracing must be stored
				and available for recall and must be of sufficient size that hand measurements
				may be made within requirement of (a) of this subsection. If a paper record is
				made it must have a paper speed of at least 2 cm/sec and a volume sensitivity
				of at least 10.0 mm of chart per liter of volume.
(h)  The instrument must be capable of
				accumulating volume for a minimum of ten seconds and must not stop accumulating
				volume before (i) the volume change for a 0.5 second interval is less than 25
				milliliters or (ii) the flow is less than 50 milliliters per second for a 0.5
				second interval.
(i)  The forced
				vital capacity (FVC) and forced expiratory volume in l second
				FEV1.0 measurements must comply with the accuracy
				requirements stated in (a) of this subsection. That is, they should be
				accurately measured to within ± 50 ml or within ± 3 percent of
				reading, whichever is greater.
(j) 
				The instrument must be capable of being calibrated in the field with respect to
				the FEV1 and FVC. This calibration of the
				FEV1 and FVC may be either directly or indirectly
				through volume and time base measurements. The volume calibration source should
				provide a volume displacement of at least 2 liters and should be accurate to
				within ± 30 milliliters.